Chevrolet Camaro 1967-2002 - No HP gain after costly mods. bad tune or exh?

before latest mods: prc stage I heads, MS3 cam, 42lb injectors, ls6 intake, long tube headers, 3" y-pipe, stock intermidiate pipe, magnaflo muf, stock tail pipes.
Dyno=405rwhp/363torque

today added: Fast 102 with Fast fuel rails, 102 tb, no MAF and running speed density.
todays dyno=406rwhp/360torque
Are these heartbreaking results due to a bad tune, restricted stock intermidiate pipe and tail pipes or could it be something else? This latest mod was very expensive for me to get no results. Can anyone help me figure this out?

Want to rule out exhaust? Put a cutout on the ypipe before is goes back to stock diameter.

FWIW, there have been a handful of people see zero gains with the 102 setups. It is VERY few and VERY far in between but not unheard of.

I would have expected nice gains with your setup however since you already had heads and an ms3 cam.

Same dyno, same tuner?

yes, Same dyno, same tuner

tuner says its the exhaust. I agree with him but I would think there would be atleast some gain.

i hope you get this figured out...

...im sure you spent a ton.

Looks to be a tad over 1,300$ maybe?

You can get a 3" manual cutout from summit/jegs and have someone weld it in for next to nothing... Jump back on the dyno for one pull and see what that does. That is cheap, should pick up power, and is easy.
It will rule out one downside to your setup.

Yes I will definatly order a cut out tomarrow. Great idea thanks

any track numbers? changes?

You posted peak numbers... Did everything else through the curve stay the same?

no track numbers and I just looked at the peak numbers but the curves looked pretty much the same. Sorry

Man your down at least 50rwhp. What size is the intermediate pipe?

I believe the intermidiate pipe is 2.75".

opening it up with a cutout willl probably help, but i think your tune has more to do with it. why speed density? put a 4" maf on it and be done. is it a stock cube LS1?

Its a forged Texas Speed bottom end also. Just to update, I havent been back to the dyno yet but I will post the dyno numbers as soon as I get them. I had developed an oil leak with the last dyno run and have it apart waiting on knock sensor grommets. The catch can was connected backwards also.

Sorry it took so long to get back with you all. I was only able to do two pulls today and heres what I got:

418rwhp/367torque

It still seems like I should be doing better than this. I still dont think the Fast-102 with T/B has done anything for me except take my money. I cant figure this out. The outside temp was 99F though. I have the dyno sheet if it helps to figure this out

Can anyone help me figure this out?Your latest mods would not produce a large gain unless you had a significant induction-path restriction. Unfortunately, your experience suggests that you did not. The LS6 intake works quite well on a 346.

I saw the factory size MAF and throttle body a restriction compared to a 102mm indution system

auto car?

what were the dates of each dyno?

Its a 6M. First dyno=May 2010, second=June 7 2012 and the 3rd was today

Trade the 102 for a 92. Im
Sure somome with big cubes wouldnt mind.

I would rather not trade for something of lesser value for the same results

I would really like to figure out why i'm down on power but I'm out of ideas. I really dont think its the tune because this tuner does this everyday for the last seven years. And well, hes also a good friend of mine and I dont want to think its the tune. I dont know much about tuning but he says, "making HP is the easy part. Its the driveability is where it gets more difficult." Would most Tuners agree with that statement? Well one more thing. I have the factory fuel pump. Is there still enough fuel pressure for my application? I would think the Tuner would notice a fuel problem though. If anyone could help me figure this out I would be very thankfull.

Your tuner’s statement that making “horsepower is the easy part” is true in the sense that it is much more difficult and time-consuming to get a MAF-less tune to a point as smooth and efficient as a stock tune. It is not true that it is always easy to get more horsepower by simply tweaking the tune. A speed-density tune is very different than a MAF-based tune. You can eliminate the question of the tune by installing a GM 85 mm MAF and your previous tune with only the MAF table altered. An 85 mm MAF will not limit your engine. A wideband will tell much about the tune and possible fuel supply problems.

I guss id start with exhaust but idk why you are on speed density either. Id change both

tuner says its the exhaust. I agree with him but I would think there would be atleast some gain.

When I worked as a tuner it is easy to find restrictions in exhaust, you can take pressure readings before the cats/mufflers to see how high your backpressure number is..you can check them in several places in the exhaust front to back and compare results to sort of Graph the numbers and see where its choking up.

What size is your exhaust and what kind of mufflers are you using and are you still running your catalyst??

There is a formula that can determine exhaust size vs. horsepower to give you an idea.

Check this out..

http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

hope it helps you out!

This last visit the tuner didnt use the wideband but he did the previous visit. I will ask him tomarrow if he noticed anything about fuel supply problems. I have a list of questions for him actually. And thanks Speed Freek for the exhaust size vs. horsepower formula. Great data. As for my exhaust, long tube headers, 3" Y-pipe and factory piping after the Y-pipe with a Magnaflow. But my last dyno run the other day was with the new cut out installed just after the Y-pipe. I scaned the dyno graph and have the file. I just have to figure out how to post it here. I will post it shortly. Thanks

Here is the dyno graph. Sorry for the poor quality. If there is something you cant see just ask and i'll post back

http://ls1tech.com/forums/attachment.php?attachmentid=362414&stc=1&d=1341665010

I would say at the very minimum, with your setup you need a good cat back with a larger intermediate pipe. Passed that there really is no reason for you to be running speed density. As said before get a 85mm maf and retune.

Yes I'd rather use a MAF. I'll look into getting one.