Suzuki GSX-R Motorcycle Forums banner

Do I need to tune after replacing a slip in exhaust?

2200 Views 12 Replies 6 Participants Last post by  BillV
I’m about to swap slip on exhausts. Bike came with a two bros exhaust with the cat deleted. It has a PCIII. I’m new to super sports so I’m not sure if it was custom mapped or what. It seems to run fine , maybe a bit of puttering at low rpms but I think that’s mainly because it’s just begging to have the throttle twisted at all times.

But now with a replacement to a scorpion exhaust, should I be getting this thing professionally tuned? Is a PCIII still functional in 2022? What do you recommend? Limited budget.
1 - 4 of 13 Posts
if you want it optimal bring it in to a dyno tuner.. or download the map

determine if your ECU has been zeroed out, and if the map is a zero map, match maps accordingly, if they still use zero maps in 22?
How do I confirm if my ECU has been zeroed out? What does that mean?
The Yoshimura slip-ons for the K7 1000 also involved removing the cat and they didn't recommend remapping so I'd expect your 750 to be the same. For such bikes the PCIII is an independent add-on. As far as I can tell, you can get it mapped for higher performance (at the expense of gas mileage) or leave it alone. Does the Scorpion exhaust require removal of the cat?

The slip-on exhausts from Two Bros and Yoshimura that involved removing the cat nearly bankrupted both companies after the EPA sued them for violating the Clean Air Act. They've since listed those systems as race-only and I think require you to sign something to that effect. I don't know how uptight Canada is about all this but there might be complications with whoever does your tuning.
Ya there is no cat anymore. The scorpion comes with the canister and a mid pipe. It would require removal if it was stock. Interesting about the tuning. I will check in on that. Or maybe my bike IS just a track bike if they ask... shhhh. ;)
You got a PC3 on it, might as well take the most advantage of it, get a custom tune

First of all:
No 2 bikes are the same, so if you want the best power out of your bike, what works for your neighbor's K7 might not work for yours

And dicking around with an online map that was originally for a 'similar' bike that had maybe less than 1k miles before dynojet made a map for it, while you're bike has seen 15 years wear and tear
will only magnify that difference

The good knews is that you have an O2 sensor standard, and this makes the ECU is capable of compensating the A/F somewhat by itself
You could simply disconnect the PC and leave it like that

Yup, especially at 1/3rd the price of a PCV

Then I guess it's too late to tell you you took up the wrong hobby if you wanted to save money 😜
Thanks, Nightbat. I may as well get a custom map. I have assumed it's set up properly for the two bros and cat delete, but something is telling me it was probably just a downloaded user map. lot's of popping. like a drive by is occurring every time I'm engine braking in town. people love it, I'm sure.

Lol... you're right. I've already spent more than expected on this bike. only 20k kms for a k7 though.. I hope it lasts a few years for me. Got a custom seat coming in too. My wife is going to roll her eyes when she sees it but I'll lie about how much it costs :)
1 - 4 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.