Hi Guys,
Can anyone out there inform me what diameter supercharger pulley should be on a '03 Z06?
System is a KB TS-9001
The kit I have, which was supposed to be for this car, has a 3.5" diameter, and some research I've done seems to suggest it should be 3.75" diameter.

Any help out there, greatly appreciated.

 

whatever one you want, just one will make more boost than the other.

 

Thanks, I'm aware of that, but I only wish to run standard boost as recomended by the makers.

I have no wish to unduly strain my motor.
A good starting point is determining the recomended, standard diameter, and right now, I'm a little confused on what that is.

Ross

 

I'll check and see if I have the actually pulley sizes.

If my memory serves me correctly:

I received a 3.75" pulley with my 2.6L KB kit. I put it on my '04 Z06 and the initial tune showed 9.0 psi at 6100 RPM and showed the kit supplied 43lb fuel injectors at 105%. My tuner shut it down at 6100 rpm because the AFR started to lean out.

I wanted to keep it closer to 7 psi, so I swapped out for a 4.00" pulley. I also put 60 lb motron injectors on the car. Now I have 7.4 psi max and can reach a full 6800 rpm with bigger injectors (11.5 AFR).





EDIT: I just checked my notes and the sizes listed are what I have written down in my notes. I believe I actually measured them at the time to confirm for my notes.

 

Thanks Hattitude, would appreciate your input.

My project car is more about looks than out and out grunt.
I would have thought 7.5psi boost would be plenty for a 11:1 comp engine, so 4" diameter pulley may be a better option for me.
My engine is low miles, and in real good shape:- would really like to keep it that way.

 

I updated the info in my first post, adding some additional info.

I'm currently at 507HP / 455TQ / 7.4 boost / 11.5 AFR (I wanted a safe tune), with the 4" pulley.

Quite frankly that is more fun than my tires will allow....

I have contacted Kenne Bell, via email, a couple times with questions after my purchase of the supercharger. They have always been incredibly helpful.

Or you can contact Jeff @ TPE, as he and Ken Christley of Kenne Bell, were major forces in KB offering a corvette kit. I'll warn you about Jeff though....... He'll try to get you to MAX OUT the HP......

Good Luck.....

 

You probably already know this, but..... the tune is going to be critical if this is your goal.

The box KB tune was a little too lean (probably because I was up around 9 psi). I strongly suggest getting it tuned by someone who KNOWS the LSx series of engines and Corvettes specifically.

The other key is street tires (equivalent to OEM). The supercharged motor will be putting out a lot more torque than stock. Street tires will spin before you over stress your drivetrain. Put on sticky compound tires or drag radials and hopefully your clutch will go before the diff and the tranny.

With a good tune and street tires, your car will last and be reliable in its stock configuration for a long time.

Disclaimer: The nut behind the wheel can destroy the best motor/ driveline set up in a matter of minutes...

Good Luck.....

 

Fantistic Hattitude, many thanks for that.

Your HP and torque figures with this boost is absolutely fine for my needs, so the 4" pulley appears to be the answer.

Please forgive my ignorance here, but your quoted AFR reading of 11.5 appears a little lean. I hasten to add thou, I have zero experience with superchargers, or tuning late gen 3 engines.
Do you possess the safe parameter AFR readings that are suitable for these Z06's.
Again, appreciate your help.

Any other member like to weigh in on this??

 

No mate, I didn't know this:- and you're scaring me.
I'm pouring over the instruction manual for this system, and KB emphatically infers you shouldn't get aftermarket tuners to mess witheir factory tune. In fact , they further claim that most of their perceived problems are by folk that mess with their factory tune and cause a miriad of problems.

It wouldn' be a problem to find someone to tune it, if I had too, but down here in Australia, and especially where I live in South Australia, they wouldn't have even seen a C5 Z06, let alone tune one. We've got plenty of gen 3's here in our local Holdens, but Corvettes are thin on the ground.

Not too worried about tyres, this car won't get used a lot, and certainly won't get beat on.
As mentioned previously, it's a project car that will eventually be just a show vehicle really. I've spent 4,500 hours fitting a heavily modified '63 SWC body ontop of the C5 frame/electronics/mechanicals, so the whole car is a bit out of left field really.

 

Well, this is a loaded question when talking tunes. There are a lot of opinions.

KB made their bones in the Ford world. They have an incredible amount of experience tuning the Ford engine family. I bought my kit when they were new to the Corvette market. I read their comments on tuning and I believe they speak mostly the truth. There are many "hack" tuners out there that would undoubtedly make their base tune worse or even dangerous. Since they can't control custom tunes and want their products to perform well, that's a great disclaimer. That's why I said have it tuned (or checked) by a knowledgeable corvette LS engine tuner. I know that KB doesn't have the knowledge and experience with corvette engine tuning that they have with the Ford's.

My experience:
When my installer/tuner finished with my kit. He did not like the way it was running. He has a reputation as a very good tuner and knows his stuff with the LSx corvettes. He contacted KB, and asked specific questions about their tune. He believed (this was 11/08) they were still learning about the LSx tune and strongly urged me to let him dyno tune my motor.

During his first dyno tune, trying to keep a conservative 11.5 AFR (some say it's OK to go to 12.5 AFR), he ran out of fuel injector at 6100 rpm. The AFR started quickly climbing. He shut it down at 6100 rpm.

I think it MAY have been due to the higher compression of the LS6, causing the base 7 psi KB kit pulley to hit 9 psi instead of the expected 7 psi. Maybe the box KB tune would have worked fine once I pullied back to 7 psi..... I'll never know.

I decided to go with 60 lb injectors and to custom dyno tune my set up. I ended up with the numbers posted.

I believe the box KB tune and the larger pulley (4" = 7 psi), would be much better than my motor was with the 3.75" pulley (9 psi). But I would still want it checked.

Those are my thoughts and experiences with the tune. I would recommend that you call Jeff at Total Performance Engineering (forum sponsor). He will give you a good, real-world, opinion of the box KB tune. He has worked with those tunes a lot, and he won't just give you the company line.

Good luck.....

PS- the car project sounds way cool... post pics when it's done!

 

Thanks a bunch Hattitude, your input is greatly appreciated.

I'm real glad I didn't run with the 3.5" pulley I got with my kit.

Reckon I'll run with the 4" for sure, plug in the standard KB tune, and then take to a reputable tuner to make sure it's safe.

If you'd like to PM me your email address, I'll shoot you down some pics of "Prodigy". Doing the final build now, and should be finished by Easter next year.

Thanks again for your help
Ross

 

You can take it to a reputable gen 3 tuner it doesnt have to be just a corvette tuner. These are the exact same engines pretty much in fbodies and your Holdens. If you got a good gen three tuner down there you can use him. I'm getting ready to finally finish my 2.8 and can't wait to get the thing tuned and running. Good luck.

 

OK, many thanks for your input. I've sinced tracked down such a tuner here that fills me with some confidence. My only challenge here is that KB is not well known, especially in relation to gen 3 engines.
At least we seem to have the pulley question solved.
Good luck with your project.

 

It makes a huge difference whether the tuner understands the KB or not! My tuner has tuned a ton of n/a, centri and turbo cars, but when it came to my 402 w/ the 2.8 KB making instant boost at super low RPM, he struggled and is still struggling. May end up taking it to someone else. Just a word of warning. Good luck

 

Thanks, I'm hearing you.
I guess, looking at your setup, you're clearly chasing big power, whereupon in my case, I just want the darn thing to be safe, and look good.