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Introducing EL TORO - THE TIRE KILLER

137K views 1K replies 106 participants last post by  JP1143 
#1 ·
Hey Guys

This thread is gonna be about building my bike - The one that shall forever be known as EL TORO - THE TIRE KILLER.

Why "El Toro" ? Because, as Borat would say, "It is STRONG, Like BULL". And the bull has great hunger for tires

I'm starting the thread because -
1. Its fun to share
2. I've learned so much from this site. Really seen some good threads on here. Its about time I start giving something back !!
3. Lots of smart guys on here. Never know when someone will give you

Anyways, I'm working on it right now, just starting the motor build. I'm going to start this thread off with some basic info, and throw some pics up. I'll keep adding pics

Basic info -

Motor -
1143 (4mm stroke, 3mm bore). Counterbalancer removed.
Pro ported head. Fresh valve job.
Carillo rods
1mm bigger intake valves
13.something compression ratio (haven't determined what I will be running exactly yet, I have 3 headgaskets to choose from - .028, .030, .036. And yes, I CC EVERYTHING to get the "true" static compression, I'm not just reading it off the box of the pistons!!
Big cams (.400 lift / 260 @ .040 intake, .358 242 @ .050 exhaust)
carpenter valve springs / yosh keepers (for durability)
Hindle full exhaust system (Superbike model, tapered headers, big dia through muffler)
Full studs
undercut tranny
Billet clutch basket
44mm throttlebodies (2mm overbore)
Powercommander
Velocity Stacks
Ceramic trans bearing
High volume oil pump gear (stock pressure relief valve though)
oil baffle
Carbon fiber ram air tubes
going to get Factory Pro to flow balance my injectors
Got a brand new K7 fuel pump that I'm going to use. Might modify the regulator for slightly higher fuel pressure (for finer fuel spray) - maybe aim for low/mid 50's
Putting in a brand new stock K4 oil pump too - never hurts .... good insurance

Extras -
16.5 inch forged mag marchesini's. Ceramic wheel bearings.
Have 16.5 cast mag Marvics for the track, stock wheel bearings. Got 5 of these really cheap, so i'd rather mess them up on the track than the nice Marchesini's!!
Road race slicks (200/70 Dunlop rear)
Superbike radiator (gonna take some work to make this work!!!)
Aluminum gas tank (ex superbike / endurance racer, 5 lbs lighter?). MIGHT run this tank, probably stick with stock tank this year due to time constraints
1.5lb battery (speedcell)
Quickshifter
Race bodywork for track. Have spare bodywork that I might convert to street bodywork for ease of swapping (also have nice clean stock bodywork that I use for the street)
2 shift lights (left one for about 10K, right for about 12K)
K5 forks, low mileage, with AK20's
Attack triple clamps, adjustable offset

Brakes -
Just bought an ISR master cylinder, can't WAIT to try it!!
Also got ZX14 Nissin calipers (8 pistons total, one pad per piston). Also haven't run, can't wait!
-2 stainless lines
Brembo 320mm rotors

Anyways. Thats just a start on the list..... theres more !!!!!!!! But that will come in time

OK, I'm going to throw some initial pics on. I'll keep adding to them, just gotta start somewhere!!

But first, lets get a few things out of the way -

A. YES, I KNOW THAT THIS BIKE IS COMPLETELY INSANE, COMPLETELY USELESS, THAT I CAN'T EVEN USE THE POWER OF THE STOCK MOTOR, OR EVEN MAX OUT THE STOCK CHASSIS.
B. YES, I KNOW THAT IF I WANTED TO GO FAST ON THE TRACK I'D BE BETTER OFF WITH A COMPLETELY STOCK GSXR600 (ok, maybe do fork springs and brake pads).
C. YES, I KNOW I'M PROBABLY VENTURING INTO AN AREA WHERE ONLY PROFESSIONAL MECHANICS SHOULD GO. I MAY BE BUILDING A TICKING TIME BOMB.
D. IF YOU DONT APPRECIATE OR ENJOY WHAT I'M DOING, I DONT GIVE A FUCK. THIS IS MY DREAM, THIS IS WHAT I'VE ALWAYS WANTED TO DO. I REALLY DONT HAVE ANYTHING ELSE IN MY LIFE THAT I REALLY CARE ABOUT. Doing this sort of thing is really the only reason I have to wake up in the morning. The rest of my life is kinda boring and shitty. That might sound pathetic, and maybe it is, but at the end of the day - at least I have ONE thing that I care about. That puts me one ahead of a lot of people.
E. Pointing out the uselessness of this build is probably just going to encourage me to do even more.... so dont waste your breath....

Anyways!! Enough of that....... Introducing EL TORO !
 

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#938 ·
Hey Guys

Sorry for the lack of updates. Been busy working on motor

Did test assembly of head & put it on block (using only the small inner Kibblewhite valve springs as "checkers", no valve seals, but basically complete head otherwise)

Leaving out the big outer valve springs, and also the valve seal, makes it really easy to push down on the lifter (I use a hardened wood rod, so as to not scratch anything). Makes it REAL easy to check PTV clearance - you can feel the valve hit the piston if they are fairly close

I leave the valve seals out, because there is no reason to be bashing the retainer onto the seal over and over as you check PTV. And, I'll have to disassemble the head again anyways to put the big outer springs in place. So seals go in at that time.

Also is a good time to get a start on doing the valve shimming. I do my cam timing on cyl #4, so I try to shim those valves to right at 0 clearance, or just slightly negative (as close as possible). I need 0 clearance for the most accurate cam timing, but I dont want to go too negative, because I'm just not sure at that point how far open the valve is, so it makes PTV a bit more fuzzy

When I do the PTV calc, I'll subtract the normal valve clearance on top of the PTV minimum for these valves. I'll use .040 / .070 as my absolute min PTV, but will aim for at least .050/.080". So, since the valve lash specs are .006-.008 intake, on this cylinder #4 with zero lash I'll aim for .044 (.050 minus .006 min clearance), exhaust on #4 then becomes .072", since the specs are .008-010" valve lash

The other valves I'm trying to set the lash to the specs, so I wont do any +/- on the PTV clearance

I'm going to start working on the cam timing. Prob gonna go for 107-109 or thereabouts.

When I get cam timing set, then I'll go back and check PTV. On cyl #4 (since thats where I'm basing my cam timing from), I'll start at... oh... probably about 16 to 18 degrees BTDC or ATDC (depending on whether I'm checking exh or int), then work towards TDC in 2 deg increments & measure PTV at each step. That will give me a nice little "map" of the piston / valve relationship

it will also tell me where the "tight" spot is (where the PTV is lowest, where the parts are the closest together). it might be 12 deg on intake, and 10 deg on exhaust (just making up numbers here)

I'll check PTV on each valve, each cylinder. Except for #4 cyl, I wont do the whole "mapping" process, unless I see something strange. If the intakes were tightest at 12 deg on cyl #4, on the other cylinders I'll just start my check a few degrees before /after that point. IE, for the intake there it would be maybe 14-12-10 deg

Also, when I check the PTV, I push down on the lifter, then put feeler gauges in between cam / lifter. Anything above a certain level I dont / cant measure, so I just put "over" on it. Such as .120". At some point the number is high enough it doesn't matter, and also, at some point, the retainer will start hitting the valve guide



Oh yeah, as you can guess, i pressed the cam sprockets on... the adjustable ones.... haha

Also, I'm using the "new style" APE manual cam chain tensioner. I believe its called the "pro" model. It really is different than the old style!!! Better ?? Dunno. I can't see it making any difference in accuracy of cam timing of course. But, it might be easier to adjust with the motor in frame.

Also, I believe they mentioned that the seals are better / more durable in this, and that might very well be true (the old style just had an Oring underneath the external lock nut). I dont recall seeing the old style leak, but I could see how it COULD have happened. The seal(s) on the new one are inside of it, so I can't really see how they are doing it, so I can't comment on whether its "better", just repeated what I was told / read

Why did I get the new "pro" model? Well, I needed one, and they suggested it, so.... *shrugs* thought I'd give it a try.

Btw, if you want a pic of the CCT, or more info, just go to APE's website, its so different than the old one you really need to see it!! I'll try to take photos of this one later


Anyways!!! Back to work. Gonna try to get cam timing (and hence PTV) done today :)
 
#939 ·
Hey guys

Sorry for lack of updates.

I swear this has been "the worlds slowest build"

I've had some non-bike related stuff thats taken up some time, but on the bike side, it seems like everything I've worked on has taken about 10x longer to do than I expected.

Part of that stems from the fact that I'm trying to bring this up to level of El Toro on the details (and it took me 3 rebuilds to finally get the details worked out).

Trying to do all of those things in a single pass (such as safety wiring - I safety wire a ton of stuff!! basically every bolt that holds fluid - oil / coolant - on the motor I wire. This excludes things like the main covers - clutch, ignition, etc)

But have had a ton of hold ups. Just stuff being a pain in the ass. I keep working through all of them, but it just takes time. And creates frustration / aggravation!!!

Theres been more than once when I've just said "I've had enough" and walked away and not done anything on it for a couple of days

Had lots of fun stuff like finding that the starter motor is damaged, the power terminal to it is broken (well, bent over at a steep angle, the insulation around it is broken, and it would only take a little shake for it to short out against the case) OK, I knew that already, so I ordered a new rear case for it, but I was gonna use the starter in the motor currently in the bike. Well, I just happened to spin that one over by hand, and it turns over pretty hard. About twice as hard as the one with the broken terminal. I know these things can have a fair amount of resistance / drag, but that one just seems too stiff

So I'm rebuilding the one with the broken terminal (putting on a new rear cover with terminal, new O rings, etc), giving it a good cleaning inside, etc. Nice thing is that the motor brushes are part of the rear cover, so it gets a set of new contact brushes. Electric motors tend to like new brushes :)

Be really good to have a good, clean, fresh, strong starter motor for this big engine!!

Anyways. Seems like everything has gone wrong that could... almost.... just been a huge pain in the ass. But I keep working away.

Motor is Jusssstttttt..... about done. Already been stripping down old motor somewhat, so I have some of the prep work done for yanking out old motor / putting new one in.

After I yank out old motor though, I'm not going to directly put new one in. I need to do some of the chassis work mentioned earlier. Some of it will be easier w/o motor in.

Or, I might put motor in, and leave it bare for a while (no exhaust, radiator, etc etc) and do the suspension / chassis work. btw, that work is mainly with rear swingarm / susp linkage.

I need to take swingarm out, replace swingarm pivots (with the +2mm offset Racetechs), then clean / lube the suspension pivot, both inside / outside

Also need to do same with suspension link - clean & lube it

Need to put on the Traxxion dynamics parts of the shock - like the manual preload adjuster (to replace the hydraulic Ohlins one), with torrington bearing (for easier adjustment, etc). Now that shock work is not contigent on whether or not the motor is in the frame.... that really doesn't matter for that part.....


Oh yeah, can't remember i mentioned, but I went with 107/110 for cam timing. The intake had TONS of PTV. So much I didn't directly measure it (it seemed like .080 at bare minimum, more like .100 everywhere). By that I mean, I started at about 20 degrees away from TDC and checked it every 2 degrees, but it had so much clearance I didn't try to -quantify- the amount.

I'm not sure if the CP's I'm using now have that much deeper valve pockets (.200 intake) than the JE's I used to use, I dont have my notes on the JE's anymore (little fire problem), or if its simply due to the difference in cams (web 483+6 deg vs 539), but PTV on the intake side is way different than my previous motor build.... or two...

Exhaust sure as hell was tight. I had to go to 110 on the exhaust (11i web cam) to get just slightly over .070". I was at say .072-074 give or take. with that tightness, I checked every single valve. I took one exhaust valve, mapped it every two degrees starting at 28 deg from TDC, and checked it every 2 degrees after that. For THAT, i used a dial indicator set on the valve bucket (actually a digital indicator versus a true analog / dial indicator, but you get the point). I used the same indicator, pickup, etc as I used to do the cam timing.

Based on the map of that one exhaust valve, i determined the "tight" range on the exhaust valve PTV. And with this cam, the PTV stays tight for a long time. From 12 to 6 degrees BTDC, the PTV clearance stays essentially the same - it might change 1 or 2 thousandths. Essentially "flat". Its not until you get 2 degrees on either side of that (such as 14 deg or 4 deg BTDC) that you even see any real "measurable" increase in PTV clearance, and even then its only about .005" or so...

So, I after mapping that one valve I checked every other exhaust valve from 14 deg to 4 deg BTDC, at 2 deg intervals. All of them were basically flat from 12 to 6 degs, all showed a slight pickup at the far ends of the measurement range (14 and 4 deg). That is good to see (the gap widening) because it shows that I've truly covered the tight range.... and that the tight range is centered in the middle of my measurement range.

anyways!!! I pulled out the camera today, was gonna take some more photos, and guess what?? Turned it on, and it just went "sizzzzzzz" and a little puff of smoke came out. I shit you not.

Doesn't seem like it destroyed the whole camera, seems like a lot of stuff still works on it (I have some pics stored that I'd like to pull off), but it will NOT focus. The screen is just one big messy blur.

My friend has a joke that smoke is the essential material that makes all things work. He's half joking of course, but he does make a point. Once you "let the smoke out of something" it typically stops working!!!!

So, yeah, digital camera gone, thank god it was older, used a fair amount, not that expensive........ but thats just how this build has gone!

So, back to work for me. Will keep ya posted.......... if all goes well I could have this on the road in less than a week. We'll have to see what else happens........

PS. When I get this thing running, I'm gonna run the shit outta this thing.... :)
 
#940 ·
how is big foxxie and the puff of smoke that came from the camera?

j
 
#943 ·
Iridium is out on the track with Big Foxie. Turns out that Big Foxie is a bad bad kitty. I will let him tell you all more about it when he gets back from tearing up the track.
 
#944 ·
Is he still alive and kicking? Curious about what numbers foxie is making

J
 
#945 · (Edited)
Jp anything new done to the motor? I've only put 1600 miles on the stroker in two yrs. How is your bike holding up against newer bikes such as the beemer zx10? I have lots of carbon built up on the valves. About to throw some bg44k and new plugs in there

J
 
#946 ·
Sent you a pm J. Don't want to high jack Iridium's thread since he's not posting or returning my calls.

Iridium met some hot stripper named Gigi, so thats been taking most of his time. He don't call but he sends me pics of her to rub it in my face.
 
#947 ·
Hey everybody

Yeah, I've been MIA. Sorry about that. JP has really been making an effort to get a hold of me, and I've blown him off a number of times. Sorry about that buddy, I really am....

Good news / bad news -

Bad news - Big Foxie needs wiring work. The bazzaz wiring has started to get loose and cause some issues - like the power cutting in / out on the track.

There are a couple of parts to that problem - 1. The bazzaz uses a TON of connectors - probably about 30 or so, if you run the full package (fueling, traction control, quick shifter, etc). A lot of this is because it interfaces in between the factory harness. For example - there is a factory wiring plug for the fuel injector. The BPD has a plug that goes into the factory plug, and then another plug that goes into the injector. The BPD sits "in between" the factory plug & injector - it intercepts the signal & then makes changes

So the BPD system has 2 plugs for everything it interfaces with. And it hits all the injectors, so 8 injectors x 2 = 16. Add in the factory plugs that it works with (8), and you end up with 24 plugged in connectors just for the fuel injectors. And thats a LOT of wiring in a very cramped space! And then you have another 8 BPD connectors for the ignition coils. Plus a bunch of other connectors that interface with sensors - like the gear position switch, throttle position switch, etc etc

2. Those plugs are starting to get loose. Some of that is because the system is just kinda old, and has had a lot of time / work on it. This was a serious racebike before i got it, and was torn down plenty of times. And, I've done the same.

And, I've probably been a bit rougher than i should have been on some of those connectors, esp on the throttle bodies. The problem is that the BPD system doesn't have what I would call a "bank disconnect" on the wiring - ie, there is no one big connector that you can unplug to disconnect all the BPD wiring on the throttlebodies for example. It all runs from the BPD box to the throttle bodies.

So, if you want to disconnecto the throttle bodies & take them off the bike, you have to go unplug about 20 connectors (16 just for the injectors) individually, and then hope you get them plugged back in just right

Anyways. What I'm going to do over the winter is hard wire the BPD box to the factory harness to eliminated almost all the small connectors, and then put in some big connectors so I can unhook / unplug the various subassemblies - like the TB's - as one piece. So instead of 20 BPD connectors and a dozen or so factory plugs for the TB's, I'll hardwire the BPD harness to the factory harness, permanently mating them, and then put a few big plug ins (like 30 or 40 pin connectors) so I can pull things off as subassemblies.

Like i said, some of the BPD connectors have gotten loose and are now creating intermittant issues - like a fuel injector cutting out for a few moments and then coming back

I ran big foxie at a few trackdays, dealt with some issues, thought I had it going well, then the power started going on/off

Violently going on/off. You can't have 30, 40, 50 hp disappear and then come back w/o warning on the track.... it will put you on your head

So I got pretty frustrated with it, and shut'er down for the season.

Been working on other stuff - doing a lot of work for my parents on their house. Did a bunch of work on their deck - seriously cleaning it (powerwashing it down to bare wood), restaining it with multiple coats, etc.

Since i was so frustrated with big foxie I just decided I would put her aside and get other stuff done....

But I'll fix big foxie over the winter. Track season is done anyways, so it wasn't a big rush.... and I needed time away



Here's the GOOD NEWS though - Big Foxie runs LIKE A BAT OUT OF HELL!!!

I had the long factory pro velocity stacks in it, because I was worried that with my super tall gearing (about 110 mph actual in first) the power might fall off in slow corners, so I figured the long FP stacks would add in some low end / midrange, and if i had it overgeared, it would help me pull out of those corners

And pull she did!

I had problems tuning her on the dyno. The connection between the laptop / desktop PC & the bazzaz unit works fine, UNTIL you start the bike. Then it works for a few seconds & then breaks connection. I think the USB plug connection on the BPD box has loosened up with time enough that when the bike is running, the vibration shakes it enough to make it lose connection.

So when I was on the dyno, we couldn't do any real time tuning. IE, couldn't run the bike, make changes, then re run it, w/o shutting down in between. Is possible to tune that way, but will take forever.....

So when i was at the dyno, we messed around with it for over an hour, trying to get the real time connection to work, and just couldn't get it

But, while I was there, and the bike was warmed up on the dyno, i said fuck it, lets do a dyno run

Now, the bike was running really lean on top, but still managed to pull out 167 FP horsepower, corrected of course.

Based on the bazzaz fuel/air sensor, I ended up adding about 15% fuel at full throttle, but this is AFTER the dynoing

So even with the top end really lean, it still pulled out 167 FP rwhp! And, honestly, with the fueling corrected it should pick up 3 or 4 hp. So I've been calling it 170 FP rwhp, which is significant. The BMW 1000's only do 160hp bone stock, and about 163, 164 with a good exhaust & some tuning

Oh, and btw, this was a step test of course (going up the tach 1000 rpm at a time, like 6000, 7000, etc, running it there for several seconds and letting readings stabilize) - not a sweep / acceleration test

Big Foxie has a SUPER wide powerband. From 8000 to 12000, the torque only varied 5% (3lb ft), and 7k and 13k were only 5% below that range

Torque looks like a tabletop. Power flattened out early, about 11,700 i'd guess, due



Big Foxie was a beast!!

Ran really, really hard on the track. NO lack of power coming out of the slow (40 to 50 mph corners). In fact, anything above about 1/2 throttle = tire spin / wheelie

And then, I decided I'd put the super short OEM velocity stacks in, I figured it might kill some midrange and add some RPMs on top

OH MY FUCKING GOD

I MEAN HOLY SHIT

BIG FOXIE RAN SO DAMN HARD WITH THE SHORT STACKS IT WAS SCARY

She didn't seem to lose any midrange / low end at all. Seemed like same killer midrange, and then the top end just went nuts !!!

Big Foxie went from scary fun fast to just scary fast!!!! I was spinning the tire all over the place and I was trying not to!! As in, spinning it at 100 mph + when I was straight up and down and rolling into the throttle carefully! And thats on a fully heated, new 200mm raceslick michelin

I wouldn't be surprised if Big Foxie made 175, 176 rwhp, factory pro, with optimized tuning and the short stacks

Those short stacks just.... seemed.... to make her a monster. Blew me away. She runs so hard with them that I bet I would have been happy with stock cams & still been able to out power about anything else on the track!! holy shit!

Anyways!! Have a buddy coming over, he had some surgery a few days ago on his sinuses so I need to hang out with him


I PROMISE I'll post more, and not be such a ghost. I just had to get away from the bike for a while, but that while is over

And I apologize to everyone, esp JP, for being such a pain in the ass. I just... needed some time off. Hope y'all forgive me

Will post more this weekend
 
#948 ·
As in, spinning it at 100 mph + when I was straight up and down and rolling into the throttle carefully! And thats on a fully heated, new 200mm raceslick michelin

I wouldn't be surprised if Big Foxie made 175, 176 rwhp, factory pro, with optimized tuning and the short stacks
Jesus...:punk
 
#949 ·
It's about f***ing time. I was getting worried that you were starting to fall for that stripper. Well, from the photos you sent me, I guess I wouldn't blame you if you did.

I told you not to use those long stacks.... they do nothing but kill power. Short ones are the only way to go. Man if your bike puts out 175hp on a fp dyno, thats freaking amazing power. If my math serves me right, that would be 175 x 1.2= 210hp on a dyno jet. I see people use the 1.23 conversion as well which would add another 5hp. Either way, your bike rocks man. I knew it would be badass man, there was no doubt in my mind.

Give me a shout this weekend. I'll be at the hospital this whole weekend wking, so I will be up all damn night.


And I forgive you for giving me the cold shoulder. Just don't let that shit happen again.
 
#950 ·
I'm putting down about 190whp or so on a dynojet and I've done some 120mph slides 15 degrees off center on pre-heated Dunlops and good pavement. Another 20hp ... OMFG.

BTW if you go with the short stacks you might find your lap times going up despite the extra power, because you'll have a hard time using it. I mean, I find myself short-shifting some very fast corners just to keep the tire from really blowing off (although this can have the opposite effect if you do lose grip, because the speed diff will be higher). Word to the wise: you have more than enough power as it is, the key to making the bike fast is making it work for you. I'm just sayin'... your milage may vary. If it puts a smile on your face, who cares, maybe!
 
#952 ·
I'm putting down about 190whp or so on a dynojet and I've done some 120mph slides 15 degrees off center on pre-heated Dunlops and good pavement. Another 20hp ... OMFG.

BTW if you go with the short stacks you might find your lap times going up despite the extra power, because you'll have a hard time using it. I mean, I find myself short-shifting some very fast corners just to keep the tire from really blowing off (although this can have the opposite effect if you do lose grip, because the speed diff will be higher). Word to the wise: you have more than enough power as it is, the key to making the bike fast is making it work for you. I'm just sayin'... your milage may vary. If it puts a smile on your face, who cares, maybe!
Yep!

I'm gonna put the long stacks back in. I did a couple of trackdays with them, and while the power was.... immense and crazy, i felt like i could control it.

With the short stacks, I just didn't feel like i could control it anymore. or, put it another way, i'd have to back off the throttle so far to be careful that I'd be going slower. Backing off 20% for control, while the bike / tires could handle a 10% backoff

So I'll go back to the long stacks and work on my riding. And, next year, I might start playing with the traction control. Its not something I WANT to rely on, but..... it might save me a bunch of money in tires. Even if I can control the bike when the tire spins & keep it up right, it only takes a good spin every few laps to really cut down on the life of the tire!

On a side note, I tried to work on my riding style some last year - I've always been a bit of a parker / screamer as the saying goes. Was better over the past couple of years, but this year I decided I would try to go as far the other direction as possible, because then the "happy place" would be somewhere in teh middle. I basically got there. I just rode the shit out of the front tire. Tried to go in as fast / hard as possible. Tried to ride the bike like a 600 (and taking it easy on throttle on exits).

I finally achieved that. An ex AMA racer told me "man, you are just hammering that bike on entries..... y ou're on a big 1000, go in slow, come out hard!!! Stop riding that like its a 600 with no power!!" hahahaha

BUT!! I did overcome my "fear" of the front tire. I have a lot more confidence for how much the front will grip, and I understand how much faster i can go into a corner, IF I want to. So that eases my anxiety on the track. I can enter at a pretty good speed w/o worry about whether I'll lose the front, b/c I've gone in a lot faster before. So I back off that crazy entry speed, get the bike turned mid corner, get it stood up quick on corner exit and blast my way out of the corner... :)

Pretty funny, for me, to have an ex AMA racer tell me, "go in slower, and just hammer the shit out of it on the exit!!" :)
 
#951 ·
Second gear goes to 129 actual, with a 13,100 rev limit

At Heartland Park, on the short "back straight" (after turn 7), I was pulling little powerwheelies down a long section of it, just for fun. I'm not a wheelie guy at all, but I was pulling the front up about 6 inches.... accelerating....

At about 10k, in 2nd gear, anything past maybe 60% throttle brings the front up, just rolling into the throttle (this is coming off a corner that is a bit of a sweeper). The front just comes up, and if you slowly roll into it more it keeps it up. I think i kept the front up for a good 200 feet on a few occasions, basically 100 to 130 mph, and still not even hitting full throttle

The bike just has "dial a wheelie" power. 3rd gear, which goes to 147 actual (13.1 rev), is reaaaaallly dicey to hit full throttle and keep the front down. I think I pulled it off a few times, but still 3rd gear is "a gear to be respected". Basically 3rd gear, even with the tall gearing, is a "wheelie / wheelspin gear"

And thats with the LONG stacks

With the OEM short stacks in, fuck me...... i couldn't believe the difference. I expected to lose some low end, kill a little midrange, and add top end rev's (with the long stacks, it revved out early.... a little below 12K peak.... the power didn't fall off after that, it just stayed flat... but it made me feel like i should be short shifting)

But.... with those short stacks.... I didn't feel like it lost power ANYWHERE. The slow corners (40 to 50 mph), it was the same feeling - anything above 1/2 throttle was wheelspin / wheelie. But above that, esp above 9k, the bike just completely FUCKED OFF

I really have to dyno the bike with the short & long stacks, back to back, to see what the dyno says. The old "butt dyno" isn't that accurate. maybe I DID lose some midrange, put a hole in the powerband, and then had a spike afterwards - and that will always seem like a big increase in power... the "butt dyno" seems to be good at sensing transitions in power...

But the bike just seemed to LOVE those short stacks. Seemed like a way bigger gain than I expected. BUT.... I will say that I did some measurements before I put the short stacks in. The effective stack height went from 50mm to about 15mm (these are the short stacks that barely intrude into the airbox). OK, that will make a difference, but.... you have to remember that while the velocity stack length was 70% shorter than the earlier amount, the velocity stacks are just part of the intake tract, and if the intake tract (from entry of the Vstack to the back of the intake valve) was say 8 inches (200mm), a 35mm difference in vstacks would be a 15% difference give or take in overall intake tract length. Which should definitely move the power band around some (biasing towards top, away from low end)

But.... The one thing that I saw when I measured the Vstacks, which really caught my attention wasn't the LENGTH... it was the INSIDE DIAMETER. The FP stacks were 50mm inside, while the OEM shorts were 54mm.

Oh, my, now THERE we have something. 8% bigger ID = 16% bigger area. All else being equal of course (which it never is). That bigger ID just might equal a higher % of flow increase as well, because you will have some "boundary layer" effects at the surface... ie, there is probably a 1 or 2mm section around the edge that doesn't flow much because the air is effectively "stuck" to the walls. Now, with a decreasing taper to the bore (above 1.5 degrees, inclusive), the boundary layer should probably get washed away by the high speed air as it narrows down through the taper... but this stuff is already way over my head, and I dont have the tools / knowledge to be able to predict / understand that.

Either way though, before I put the short stacks in, that big increase in ID & therefore intake area told me that it was -possible- that the short stacks could show a huge pickup in power. IE, the long FP stacks with their small inside diameter could, maybe, be somewhat choking off the flow..... So going to the short stacks would not only change WHERE the power occurred (ie, moving the power side to side on a dyno chart, but could also change the overall AREA / HEIGHT of the power)

And that might be right, because the bike just seemed to EXPLODE with the short stacks.

It seemed like the power "moved up a gear". IE, the bike started spinning the tire & pulling wheelies iin one gear taller at the same rpm, same throttle position, with same tires

Seemed like with the short stacks, the bike wanted to aggressively spin the tire and wheelie in 4th gear... and that goes to 167 actual!!

If Big Foxie is a dragon, then those short stacks woke up that dragon... and that dragon was pissed!!

Honestly, I'm gonna go back to the long stacks, for a while at least. The short stack power was just too much for me. And that takes a LOT for me to admit!!

PS. Tim Radley sort of predicted this. He told me he thought the FP long stacks would make the bike "not want to rev worth a shit".... and might not even give me any more midrange.... He told me to put the short stacks in, i'd make more power everywhere

Oh yeah, I'm still very impressed with Tim's headwork. Maybe more impressed than ever. If I had to guess.... I'd say that I bet .... 60% of the power gain that I got is from his headwork, esp ifyou talk about part throttle power. The other 40% is from the bore increase (to 1070) and cams....

So, I'm DEFINITELY a believer in Tim's headwork. I highly recommend it!! in all honesty, I bet I could have done his headwork, the 1070 kit, and kept stock cams (but retiming those cams of course), and been VERY happy with the power


One last thing, the HP figures I discussed before, were with 91 octane pump gas, stock air filter, a big, brand new 530 chain...... Think what this sucker would make with oxygenated race gas, a race only filter, a worn out lightweight chain, etc............hahahaha

:)
 
#954 ·
I know I showed you my stacks before or maybe I haven't. But are the short stacks you used shorter than mine?
 

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#955 ·
JP,

The vstacks I have in now are OEM, super shorts (I dont know if they make shorter ones, but I dont see how that would be possible). I'm not sure what they came out of, they were the stacks in the airbox when I got the bike - its what KWS put in when they were racing it in superstock. I THINK that they may be the outer stacks that come stock in the K7/K8 1000's (oem runs a longer pair in the middle, but I put in all 4 shorts)

They stick up only about ... 5mm, 10mm max, above the surface of the airbox. The effective length is a bit longer of course though, because some of the vstack goes through the airbox to mate with the throttlebodies of course

Btw, I think you might have told me before, but who made your stacks? Those look nice

My favorite stacks ever, at least for the K4's (not sure if they would fit the K7s) were the Attack velocity stacks. Pretty short, I'd say 10mm shorter than yours, but the design was really cool. Two piece aluminum that bolted together, and also had a bolt to tighten them to the throttlebodies. Big suckers too - the mouth was so big on them that they actually had a flat spot on each side so they butted up against each other in the box. I actually had to file down the flats a hair (maybe .005 or .010") so that they would fit!!

Those suckers sold for $500 new, i picked up my set for about $175 used.

Going out on a limb here, as I think about it, I THINK they would fit the throttlebodies in terms of ID, OD, but I think the K7's have a different spacing on the TB bores. I've heard that, haven't verified it. If the bore spacing was wider than the K4's, they might fit, but if it was narrower, no way....

Anyways. I'm not sure if they would have any performance gain over what you're running, except for the change that would occur due to different length, but they were just really cool from an engineering standpoint....

Yours look nice :)
 
#960 ·
Short stacks with the secondaries taken out is the only way to go. You have to get it mapped to feel the full benefit. It just seems like the power come on quicker. Thats my opinion anyway.
 
#961 ·
JP1143, did you find taking the secondaries out resulted in more off idle and midrange torque?

I did on a k7 750. It's not placebo or a non-linear torque curve making it feel more powerful IMO. Time to maximum power is noticeably shorter, that is I find myself having to shift through the gearbox much quicker when I give it WOT.

Is that why you are recommending the short stacks?
 
#964 ·
That's the quickest and easiest way to do it.

How much power will you lose with the shaft still in, maybe someone else knows exactly, my guess about 2hp? But you gain much more with the STV plates out. Some people don't like it though.

I've removed the shaft on mine and fabricated a small shaft from aluminium for coupling the STV motor to the STP sensor. I have two sets of throttle bodies, stock and modified and have AB'd them a few times.
 
#965 ·
Hey kwaka10r, what kind of bike do you have? I'm assuming by your screen name that I think I know what the answer is, but I could be wrong.
 
#967 ·
IridiumRed! Where the hell are you?! Update!! Big Foxie!!
 
#968 ·
Hey JP. Damn u JP. I've been fighting with Big Foxie for a while... just lots of details, lot of it wiring related

Was getting kinda burned out / depressed over the thing for a while.

But JP has gotten me fired up again (we chat via txt messages on the phone a fair amount). So i'm back up to speed

Gonna have the bike done / running soon. And I'll put on plenty of posts, I promise :)

As General Douglas Macarthur said in 1942, when the Japanese forced him to leave the Philippines - "I SHALL RETURN!" (as the Japanese tried to expand their pacific empire, and while we in the USA were still knocked back on our heels after Pearl Harbor).....


And he did return too. In 1944 we, led by Macarthur, went back to the Philippines, and kicked the living shit out of the Japanese who had made themselves a little too comfortable there :)

Barely a year later..... and the Japanese were signing the peace treaty ending WW2, Sept 2, 1945, ceremonies held on the deck of the USS Missouri, one of the greatest battleships that ever to sail the ocean :)
 
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