#1 TA WS-6

The exhaust is the ONLY mod on the car so far. I decided to dyno the car after every major bolt on for the benefit of the community. The threads below are the dyno, weight and first track passes for the car in stock trim. (no npp)

http://forums.corvetteforum.com/c6-t...se-ls3-m6.html

http://forums.corvetteforum.com/c6-t...ock-08-m6.html

On to the new stuff. I installed the exhaust in my garage using ramps and and jack stands. The install was easy except for the axle back. Tip: loosen the sway bar! First I tried to reuse the ls3 gaskets. There was a noticeable exhaust leak. You must use the ls7 gaskets.

The new sound is great! I am considering taking the mufflers back out to do the mod for a little more volume. You will see by the dyno that power was increased EVERYWHERE! I had them overlay the new dyno over my previous best so you can see the difference more easily. I did not expect the exhaust to lean the car out as much as it did. Last time AFR dipped all the way down to 11.0 this time it only went down to about 12.2. These runs were on the same dyno. The shop is heated so weather was about 65deg for both runs. Anyway, on to the good part.



Pretty good gains for the price if you ask me!

achilds

Did you tune the car for the new set up.

da vette guy

Excellent,been looking for this ...i'm going to try and do one of these on my 08 a6 soon(got the parts but no garage)

#1 TA WS-6

Nope no tune. It was quite a shock to me that it leaned out. 2000 mi may have helped. Lol

jmudreamvette

I did the same with NPP axle back and a tune. I can't chance leaning out the car, pistons don't like it. I really like mine.

PCMusicGuy

Finally, proof. Increased power everywhere and roughly 20HP and 15TQ peak with no tune. Results speak for themselves. Thank you sir.

///DarkSide\\\

Interesting, great gain for the price

IIRC & correct me if I'm wrong, LS3's are getting ~10hp w/ just Z06 headers, so adding the rest to give you 3" all the way back is worth another ~10hp. Roughly...

8850

I got exhaust leaks too with the stock round gaskets and recently changed out to the Z06 (LS7) gaskets. No problem now.

Here's my dyno with the Z06 manifolds/exhaust and also with an Airaid intake. I did some tuning myself with HP Tuner. This was done on a Mustang dyno.

http://i959.photobucket.com/albums/a...o312-12-09.jpg

SpinMonster

I hesitate to comment on threads like this because groupies of some mod always assume you are just 'hating' when in fact I am simply pointing out a serious flaw in the test/comparison. That said my comments are not for or against the exhaust system which is of benefit but isnt getting you 20/15 to the wheels. That said, here is why.

You cant take an untuned car running pig rich to represent 'part a' and install "part b' which by chance happens to be running a more optimum tune. This car would have made 12-15HP over the untuned baseline just from leaning it out. The car must run optimum fuel and spark curves to eliminate the difference from what is exhaust and what is tune.

Had the car been tuned to run the same a/f curve the differences would not have been 20/15. I have witnessed a gain of 9/7 at the wheels when the entire system was installed on a tuned car and then retuned for the change. A car that was fully tuned running 13:1 air fuel for example would then need to be richened up with the install of the system. This car happened to need the change that it gained from the swap which isnt always the case.

All exhausts lean you out over stock.

To the OP, thanks for sharing the info.

SpinMonster

Another member added the Z06 system to his bolt-on LS3 and saw 2hp/9rwtq from just the cat-back added to his Kooks 1 3/4 headers which hit near 430rwhp if I recall.

This is a great mod for cars in California that have the visual check to deal with.

3 Z06ZR1

That was me! I was using the stock 2 1/2 pipe form the base ls-3
mufflers. Graphed to the Z mufflers. I was 2hp 9 tq peak but under the
curve was 9hp/9tq everywhere. Was not enough exhaust with a V-3 S/c
which was 514hp/453tq with the above set up. Then went to 578hp/530tq with complete swap to 1 7/8's (ZO6) headers and full 3 inch out to another set of z-mufflers with the stock z pipes attached!
The Z stuff will make a Ls-3 run better and is worth while for sure!

#1 TA WS-6

Darkside, is your name ricky by chance?

venomws7

Great numbers but you need a tune for sure the car looks very rich...


Do you mean the owner of that Badass 1200+rwhp Viper

///DarkSide\\\

That being said, IYO it's highly probable that ~50% of the OP's gains came from leaning out the car?

In the interest of preserving my 08's warranty, could doing his mod without a tune lean out the car to where it's dangerous & wouldn't the car relearn itself into running rich again after putting some miles on it?

The CA inspections are why I never put headers on my cars. I R&R everything from the headers back every 2 years, but doing same to a set of headers isn't worth the PITA.

LS2-Zomb!e

White_Lightning

Thats not ricky..

Question, what made you go with a z0 exhaust setup? just FYi,

my o8 stock put down 390 rwhp, 398 with halltech. Moved to a K&N and put down 408 rwhp, 416 with a 5 min tune.
Threw on some LG Super pro 1 7/8" headers 3" all the way back to my NPP and put down 437/424.
Keep in mind the z0 catback is NOT a true 3" Vs the npp 2.5. you gain maybe 1-1.5' of 3" with the z0 and then it necks down to 2.5 going into them muffler. my numbers are into an 08 NPP 2.5" catback.

SpinMonster

Stock LS3's with a tune are about 400/400 (I've seen as high as 407) so yes I think 10hp came from the tune.

It is unlikely to expect the a/f results to be predictable to say it would be safe without a tune. In fact I think the opposite is true and it would be dangerous.

Cars do not learn a/f ratio curves on their own. This rumor has persisted forever. If this were true, the OP's car wouldnt have shown an 11.2:1 a/f ratio after driving it for a while. What a car does learn is minimum airflow/TB blade positions. It learns to compensate when a cam doesnt have enough vac at idle. Resetting the PCM (disconnect the battery) wont show an A/F ratio change but it will make a car less friendly at idle if the tune wasnt optimum for the cam in it. In the old C5 days running the MTI 'T1" cam, I had this issue when LS1EDIT was new and couldnt tune with the airflow adjustments of today's software platforms. If I ever worked on the car and had the battery disconnected, it would take a day or so for the hunting idle to settle down. It had nothing to do with long term fuel trends or WOT curves.

It would be dangerous for a PCM to self-adjust fueling. If a tune is walking the A/F, its because the airflow table is wrong or there is a temp related table issue. I've never seen it but hear it happens from other tuner's experiences.

Torlow

That makes sense. It would also apply to LT headers and gain claims by the various vendors.

Spin -- what is your experience of gains due to LT's only?

SpinMonster

Header tests by tuners tend to be spot on. They tune a car before then add the headers and tune again. The LS3 makes 425 +/- 5 with most headers. I've seen 430rwhp. Headers on the OP's car will produce 12-19HP more over the 411 its at and even more on the TQ, having seen 427rwtq compared to 404 here and you can very much feel a 23rwtq increase. One needs to take the situation into account. This is a real option for Cal cars.

The tune from header to header is not the same. I swapped one manufacturer 1 3/4 header for another 1 3/4 with longer primaries and the tune needed major rework. Where a system is efficient, it wont run as much timing and a/f will vary at different rpms.

HC Mechanic