z0quick

This will be an official before and after dyno thread on power gain from these headers. I know this has been done before, but I am glad to be able to contribute since I have easy anytime access to a dynojet. I am expecting to see some nice gains, but after seeing my base results, I dont understand how I could have much more power available.

Build:

2001 Z06

BEFORE LG Street Headers:
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-Blackwing Intake
-2002 LS6 Cam (due to spinning a lifter on the original). SO basically my motor can be treated as an 02+.
-B&B Bullets
-Powerbond 25% UD Pulley
-Stock Manifolds, stock cats, and stock h-pipe
-Fully tuned by me - 13.0afr with only about 24*

I dont have the advance very high because I am spraying, and I will leave it around 24 for both tests. The only thing I will change is fueling if the headers change it much.

RESULTS: 395rwhp/375rwtq STD 385rwhp 369rwtq SAE

AFTER LG Street Headers:
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UPDATE (12-17-08): Headers are in, dyno results coming soon.

UPDATE (01-18-09): Finally got the dyno results. I am really disappointed actually. The car really didn't make any more power. I am running the LG's with off road pipes and B&B bullets. The dyno tests were done on the same dynojet.

Explanation of the dyno results:
Dyno #61 was in December and was with stock manifolds, cats, and b&b bullets: 393.23hp/384.45tq
Dyno #62 was in January and was with LG Street Headers, Off Road Pipes, and the same b&b bullets: 393.25hp/385.18tq

Comparison Dyno Sheet

I really at least expected to see more power under the curve, even if the peak hp was different. I am baffled as to how it didnt make any more power.

Z06_BluByU

:

GT-R Killer in the works...

Eddie 70

Wow those are some pretty impressive numbers to start off with. Looking forward to seeing the after numbers next week.

dr evil

Wow those are impressive numbers for a basically stock + BB Bullets.

BonestockZ06

I think these are the highest numbers I've ever seen for your mods. Most people can't get there even after full Exhaust upgrade.

z0quick

I know, I think the pulley helped a lot. I am excited about seeing what the LG's are going to do. I am expecting I should be somewhere around 400SAE after the LG's. And the 385SAE last night was in 70* outside air...so it may be cooler when I dyno it with the LG's next weekend.

falcon5619

The underdive pulley is worth 6-10rwhp. You made great power because you leaned it out to 13.0 AFR. Plus the cooler intake air temps helped out a bit.

I did a baseline dyno on my 02 Z06 before I put the cam in. It had a Haltech Venom intake and LG Street Headers no cats. Otherwise the car was bone stock. It did 389rwhp, 355rwtq on a Mustang Dyno. The intake air temps were 88 degrees, AFR was at 12.6-12.7, timing 24 degrees.

After the 224/228 cam and 10-12 degree cooler intake temps, it did 432rwhp, 392rwtq. AFR 12.6, timing 26-27 degrees. Same dyno, dyno operator, etc.

The LG Streets should be good for 20-25rwhp if matched with a good air intake. Once it cam breathe then add the cam for another nice shot of power.

falcon5619

By the way, don't get caught up on the dyno numbers per se, just focus on the measurable gains each mod contributes. Be careful with running 13.0 AFR. That is a little lean for my taste but I know you will make the most power around there. Just don't push the edge for another 10rwhp. That is the difference I have seen between an AFR 12.6 and 13.0.

bullitt4110

Those are impressive numbers for sure! I have seen it once before so I know its possible, it was an 03 with a Vararam and bullets I think it made after the tuning 382 and dont remember the torque.

Savior1974

Great numbers. My Ziptie Mod & Tune 03 Z06 made 385whp 368rwtq SAE on a Dynomite Land & Sea Dyno.

Milan

13.0:1 is not lean for an NA car. It's on the richer side of "optimal".

falcon5619

Agreed, but with the accuracy of the $200 widebands we use to tune I tend to error on the rich side a bit. You may be running leaner or rich than you think.

z0quick

FYI 13.0 is the industry safe mark and is actually still a bit conservative. I am a professional tuner and have easily tuned over 100 vettes. 13.0 is not optimal, more can be had by going a bit leaner, but then combustion temps are increasing to an unfavorable level and knock becomes more of an issue. All motors react a bit differently and all can have a slightly different optimal AFR. When this car was at 13.4 it was making a few more ponies, but that was a bit too lean for my taste. I wanted to keep it safe and mainly tuned it to 13.0 because I will be spraying the car and the nitrous usually take about 1-1/2 off the ratio.

A typical N/A tune should be around 13.0
FI or nitrous should be between 11.5 (safe) and 11.9 (high safe).

We just finished a speed density tune on a twin turbo vette and made 746rwhp (STD) at about 11.4-11.6afr with ~ 13* advance.

z0quick

Okay not a bad point, from my experience the AEM widebands are dead on with the dynojet's. I have a lot of respect for the LM guys, but the LM1's and LM2's always read a lot lower than the AEM/Dynojet. For example, when we were tuning the 750hp vette the other night the dynojet said 11.5 and the lm2 said about 11.0.

falcon5619

Thanks. Good to know.

From your experience, if a wideband sensor is accurate (calling for stoich) around idle and cruise then do you trust it at WOT? Just looking for some peice of mind since my whole tune is dependant on the accuracy of the wideband.

I have my sensor installed in the drivers side collector. Were you testing at the tailpipe?

Thanks.

Greased

Look forward to the results....

z0quick

No you can't really trust the wideband based on a type of 14.7afr at idle type of situation. We've seen the LM1&2 match the AEM and Dynojet at idle around 14.5-14.7 and then be a full point off under WOT. What wideband controller are you using?

That is a fine place to put it, especially if you have cats on the car. Yes, I was testing at the tailpipe on my car in particular which will show me a slightly leaner than reality reading.

falcon5619

Thanks for the feedback.

I have the LM1.

THE TECH

Can't wait to see the results.

VIPERBLUELX

rather than rely on a wideband, just make a WOT pull and pull some spark plugs and read them