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Discussion Starter · #1 ·
Guys, I tried posting this in another forum with no results. I was informed by a reputable performance shop that I should remove my stock exhaust camshaft and replace it with a stock intake cam from a 03 750. They said this works great after the heads have been milled down in addition to a port and polish job which includes adjustable cam sprockets too. They claim this mod alone with a full system and a remap brings mid 170's in HP at the rear wheel. This shop does this all the time but they want too much money for the mod and they won't tell my how to time the cams together for max power. Some big secret I guess, they wont give me the minute detail since I'm doing all my own work. Any comments or experience with this? Any takers?
 

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yes, the 750 cam swap is a well known mod here on GDC. Some say its worth about 5 HP...You don't have to have all the head work done though (unless you want to). The Cam mod by its sels is only worth about 5 HP though...Thats about what you get from the Yosh St-1 Cams. I'm not sure on the timing. I know they say 105/105 for my setup. I know there are people here who have done this mod. Hopefully they all haven't sold theirs and bought the K5's....Seems like all of us "Dated" gixxer riders can't get the help that we used to around here...
 

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Pull the head because you will want to install 750 springs. The 1k springs suck. Yes, get the adjustable sprockets pressed on. From what I was told you will see about 13hp increase (flywheel).
 

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600 cam and springs work too.
600 cam will have a bit less top and a bit more torque.
You have to be careful with PTV if you keep your stock pistons. I would say the lowest #s for ex cam timing are 106 with the 600 and 107 with the 750. Try 104 for the intake.
Do the valve springs, 600 or 750.

PS- putting the adj sprocket on the ex cam is the tricky part. Standard directions are out the window since you have changed the application.
 

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Just how much are they charging?
Remember the head will have to come off (600/750 valve springs), you will definitely have to 'degree in' your cams, and listen to Flip and check the PTV.

PS- putting the adj sprocket on the ex cam is the tricky part. Standard directions are out the window since you have changed the application.
Thank MRMW for this picture:

 

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Pull the head because you will want to install 750 springs. The 1k springs suck. Yes, get the adjustable sprockets pressed on. From what I was told you will see about 13hp increase (flywheel).
No need to pull the head off and replace the springs. With the 750 intake cam you will be fine. Now if you use a set of WEB cams then yes you will want to replace the vavle springs.
I had this mod done with a few other things, and very happy with it, and was gauranteed it will very reliable. but it still comes down to how much more money you want to spend.

My results
 

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that curve is da-shit

is that with web cams

i wanna do it

not being able to see your stock graph - have you lost much lower down or is it still grunty as a mo-fo
 

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that curve is da-shit

is that with web cams

i wanna do it

not being able to see your stock graph - have you lost much lower down or is it still grunty as a mo-fo
That is with the 750 intake cam, manual cam chain, 750 stacks, pair vavle mod, TRE, and remap of the stock ECU. I never had the bike dynoed stock... but I did get it dynoed with a Tiforce slip-on, 750 stacks and tre and it pulled 155.5
 

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i have most of those mods and a pc3 usb too - you are confident the stock springs are up-to scratch,

i think i will have a talk to my local tuner to price the job up as ride in - ride out

ps what is the bottom end pull like - your mid range looks good pulling over 75 lb/ft right upto max

does it spin up quick - or are their any characteristics you feel are a downside......
 

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Lee from Lee's Performance in Charlotte N.C. did the work for, and he said out of the hundreds that he has done he has not had one single problem...not one. Basicaly he said it was like having a stock bike again. The 750 cam is OEM..... and another good thing about it is, it's all drop in stuff. So unless you really don't have a good person to trust or a good engine builder, you don't have to worry about someone going deep into your motor. If you have some mechanic skills you can actually do this yourself.

The bottom end feels really strong. The only thing I noticed is she has a slight hesitation if you nail it in the lower gears (1st,2nd). But this could be do to the fact I don't have a PC. And as you know there is only so much you can tune the stock ECU compared to a PC. But after that... oh she pulls like a freight train. You just gotta love that feeling when your going through the gears and you feel that pull on your arms and you start to slide back in the seat as you try to grip the tank.

The engine does spin up quick. And after the little hesitation power comes on quick....I mean quick. And the exhaust note has a completely different sound. It was deep and fairly loud before... now it's really deep and just screams.

The only downside is the little hesitation. Which can be cleared up with the addition of a PC which I might add later. But as far as now goes.. I am really pleased with it. Lets just say my buddy with a ZX12 with 182 hp can't get passed me now
 

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So the 750 intake cam needs the stronger 750 valve springs in it's original location in the GSXR750, but in its new
home on the 1000 exhuast side with reduced diameter buckets it needs softer springs?
Baloney comes to mind.
 

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you do not need to put in the 750 springs. i didnt do it to mine when i first did the mod and i rode on the street for about 6000 miles, no problems. I tested them when I took them out and they were still good. I then made it a race bike and since I would be in the higher rpms most of the time i decided to put the heavier springs in. I have done this mod on a lot of bikes half with half without none of them have come back with issues. I would run the numbers at 107 intake 104 exhaust. I would expect gains of about 5 to 8 hp with just this mod. Not all bikes have the same cam numbers out of the factory.
 

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So the 750 intake cam needs the stronger 750 valve springs in it's original location in the GSXR750, but in its new
home on the 1000 exhuast side with reduced diameter buckets it needs softer springs?
Baloney comes to mind.
Well as they say the proof is in the pudding. If you run balls to the wall 24/7 or have an all out race bike, then yes you might want to replace them. But for street riding or occasionaly track time then you don't need them. And with the many Lee has done and no problems out of one I guess that speaks for itself. And I do believe that with his reputation he would not build something that's going to make your bike shit. Sometime what's on paper does not always equal up to tested and prooved. If I have any problems then I will let you personally know.
 

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What I am hearing is that you have one recommendation for street squids who never rev their bikes and another for
users that will actually use what the new cam has to offer. If that is the case then a street squid doesn't need the cam
to begin with.

I know from experience what will happen if you don't change the springs.

 

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stam, I guess you are referring to my post. if so you got it wrong. i never said a street rider would not benefit from it. what i said was a street rider does not need to put them in there. a racer may not need to put them in there. i am telling you what I know about the springs. If I said that the street rider would not benefit from the cam because the horse power is in the upper rpms I could understand your point, but i didnt so I am not sure where you got that from. the mod is benefical from about 5k to 12k. I would guess even a street "squid" would ride somewhere in between that.
 

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I would like to add I have been doing this mod since the 1000 came out in '01. I would think if there was going to be a problem, it would have happend by now. Stam Ive seen cams like that in bikes that have no mods.
 

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What I am hearing is that you have one recommendation for street squids who never rev their bikes and another for
users that will actually use what the new cam has to offer. If that is the case then a street squid doesn't need the cam
to begin with.

I know from experience what will happen if you don't change the springs.

Is that a 750 intake cam and just what type of riding was the bike put through? Sure if you dog something out shit will fuck up or break. Also is your experience from building many many different bikes with different aplications...or is it from your own personal or on a friend here and there bikes? You very well should know from being on this board, many have used this application and have not had one problem. Like I said Lee is a reputable guy that has tested different aplications that work not just for h.p. alone.... reliability. I don't believe he would put something in your bike that is going to fuck up. Have you heard of any complaints about his work... on this board or any place else... oh his dyno reads high..... Sorry but I have delt with Lee and not heard a bad thing yet. But I don't know you from jack now who am I going to trust. ......
 

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Discussion Starter · #19 ·
Hey guys...sorry it toke so long to get back. The mod with cams, port and polish, retiming and remaping on dyno is right at $2000. I am doing all the work myself minus the remapping and dyno tuning...and also the milling of the heads. Thanks for all your replys and advice. I'll post my dyno runs once this is all done here in the next three weeks or so.
 
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