Added Dynatech long tubes, results within.
Thread Starter
Drifting
Joined: Jul 2004
Posts: 1,663
Likes: 16
From: DFW Texas
Added Dynatech long tubes, results within.
2000 Corvette FRC M6
Before headers, 333.9 rwhp, 333 rwtq.
After headers, 335.0 rwhp, 343 rwtq.
Mods before longtubes are Vortex air box, LS6 intake, x-pipe, B&B PRT axle back and stock tune. The car dynoed 333.9 rwhp and 333 rwtq. I added Dynatech long tube system, Shaner throttle body, and had the car tuned. 335 rwhp and 343 rwtq. I'll have graphs tomorrow but the a/f was at 13.0. This is much lower then I expected. I'm have no idea what's wrong. O2 sensors seem good according to the tuner, air/fuel is good, and no exhaust leaks. The temperature today is about the same as the last time I dynoed and I used the same dyno. The car feels stronger but the numbers don't show. Does anyone have suggestions?
__________________
Before headers, 333.9 rwhp, 333 rwtq.
After headers, 335.0 rwhp, 343 rwtq.
Mods before longtubes are Vortex air box, LS6 intake, x-pipe, B&B PRT axle back and stock tune. The car dynoed 333.9 rwhp and 333 rwtq. I added Dynatech long tube system, Shaner throttle body, and had the car tuned. 335 rwhp and 343 rwtq. I'll have graphs tomorrow but the a/f was at 13.0. This is much lower then I expected. I'm have no idea what's wrong. O2 sensors seem good according to the tuner, air/fuel is good, and no exhaust leaks. The temperature today is about the same as the last time I dynoed and I used the same dyno. The car feels stronger but the numbers don't show. Does anyone have suggestions?
__________________
Last edited by CNB; Dec 1, 2004 at 09:18 PM.
Pro
Joined: Sep 2003
Posts: 731
Likes: 0
From: Calgary Alberta
My A4 dynoed 289 at the wheels stock.
With blackwing, LS6 intake, 85 mm MAF, Shaner S2 throttle body, B&B shorties, Random Tech Cats and x-pipe, Breathless Performance airbridge, B&B PRT exhaust, and 3.42 gears (slightly more drag = reduction in dyno numbers), my last dyno reading was 335.9 at the wheels.
Based on your mods you seem to be right on with your last dyno numbers.
With blackwing, LS6 intake, 85 mm MAF, Shaner S2 throttle body, B&B shorties, Random Tech Cats and x-pipe, Breathless Performance airbridge, B&B PRT exhaust, and 3.42 gears (slightly more drag = reduction in dyno numbers), my last dyno reading was 335.9 at the wheels.
Based on your mods you seem to be right on with your last dyno numbers.
Le Mans Master
Joined: Oct 2003
Posts: 6,126
Likes: 19
From: Streamwood illinois
when i initially put on my dynatechs i saw no gain in mPH or ET at the track. It was running very rich though and needed to be leaned out quite a bit. After I did some tuning I gained about .15-.2 and 1.5-2 MPH. Just curious on the graph, i can compare it to mine prior to my tuning the car.
my run w/ 4.10s, vararam and dynatech headers:
Dave
my run w/ 4.10s, vararam and dynatech headers:
Dave
Last edited by T_Vert; Dec 2, 2004 at 12:02 AM.
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Team Owner
Joined: Aug 2003
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CNB your before nbrs do seem a bit high for those mods. What were the A/F ratios before the headers? Perhaps it was running lean with those mods, and got you those impressive before dyno nbrs and now that the car is running at the 13.0 range with the headers and the new tune, the results don't seem so great?
Based on the mods, as it stands right now your car is about where it should be. In the 335/345 range.
Think about it. If you had gotten say 19 RWHP/20RWTQ above the initial 334/333, you would be above 350 RWHP with just bolt ons.
Thats not easy to do and you can probably count the C5s here on one hand which dyno at 353 RWHP with just bolt ons. In fact, you will periodically see people asking if it is possible to get to 350 RWHP with just bolt ons.
Based on the mods, as it stands right now your car is about where it should be. In the 335/345 range.
Think about it. If you had gotten say 19 RWHP/20RWTQ above the initial 334/333, you would be above 350 RWHP with just bolt ons.
Thats not easy to do and you can probably count the C5s here on one hand which dyno at 353 RWHP with just bolt ons. In fact, you will periodically see people asking if it is possible to get to 350 RWHP with just bolt ons.
Thread Starter
Drifting
Joined: Jul 2004
Posts: 1,663
Likes: 16
From: DFW Texas
The a/f on my before headers dyno was lean now that I look at it. It was at 13.0 at 4.5 rpm(x1000) and then held to about 12.8 for the rest of the run. I was expecting 350 rwhp after the headers. I have seen m6 header and bolt-on cars do 350 before so that is where I set my goal. Even with a lean a/f before the headers I still expect more then 1 rwhp with the addition of long tube headers. I did gain area under the curve but it was not on the low end and it wasn't very much. It was in the upper rpm range.
Last edited by CNB; Dec 2, 2004 at 12:29 AM.
Safety Car
Joined: Apr 2004
Posts: 3,739
Likes: 10
From: Austin, Texas
CNB, are you the original owner of the car? Is it possible that, if you are not, the original owner had it tuned while still in stock form?
With the numbers posted for stock, and your statment about the A/F being lean on your "before headers dyno", that might be one possible explanation.
Still good numbers either way
With the numbers posted for stock, and your statment about the A/F being lean on your "before headers dyno", that might be one possible explanation.
Still good numbers either way
Pro
Joined: Jun 2003
Posts: 702
Likes: 0
From: Castle Rock Co
Originally Posted by CNB
If you're being sarcastic there is no need for that. I can roast the tires from a second gear roll also. I'm just trying to figure what happened with the dyno runs.
I am being sarcastic, but I do believe your dyno runs are easily explained by a number of other factors besides the headers not adding power.
The trouble is that alot DYI'ers have posted results from the Dynatechs, and they have gotten a bum rap, and the folks that like to brag on their brand jump in on these threads and say, see I told you brand x is better than Dynatech, my tuner (ususally) got me 40hp more.
Also the second gear roll tire roasting impressed the heck out of me because I live at 6200ft altitude, and the car would not do that before I installed my Dynatechs.
Team Owner
Joined: Mar 2002
Posts: 47,647
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From: Queens, New York Life begins at 183 mph....
St. Jude Donor '08-'09
When I had my kooks LT headers, Hi flow cats, and xpipe installed, I also had it dynotuned using LS1-edit. Before, I only had a blackwing, CF airbridge and a Z06 titanium exhaust. All together and after the tune, my A4 came in at 322 rwhp and 328 rwtq. It sometimes surprises me when I see people post up higher numbers than mine with less mods (intake, maf and exhaust for example). I know that MN6's dyno at a higher number with everything else being the same. She still pulls really hard and is a night and day difference from my previous setup.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Your stock tune seems very high to me for the mods. I had a Blackwing, high flow coupler and Ti exhaust and peaked at 305. My tuner, also a 2002, had a duplicate of my curve for his car with a peak at 307. Both are MN6 cars. Your final seems to be right where it should be based on my experience with my header installation. I personally think you are sitting pretty good with your final results, and would tend to discard the first. Any chance the tuner grabbed the wrong baseline curve from the files?
Instructor
Joined: Oct 2002
Posts: 181
Likes: 0
From: Windham NH
Originally Posted by CNB
2000 Corvette FRC M6
Before headers, 333.9 rwhp, 333 rwtq.
After headers, 335.0 rwhp, 343 rwtq.
Mods before longtubes are Vortex air box, LS6 intake, x-pipe, B&B PRT axle back and stock tune. The car dynoed 333.9 rwhp and 333 rwtq. I added Dynatech long tube system, Shaner throttle body, and had the car tuned. 335 rwhp and 343 rwtq. I'll have graphs tomorrow but the a/f was at 13.0. This is much lower then I expected. I'm have no idea what's wrong. O2 sensors seem good according to the tuner, air/fuel is good, and no exhaust leaks. The temperature today is about the same as the last time I dynoed and I used the same dyno. The car feels stronger but the numbers don't show. Does anyone have suggestions?
__________________
Before headers, 333.9 rwhp, 333 rwtq.
After headers, 335.0 rwhp, 343 rwtq.
Mods before longtubes are Vortex air box, LS6 intake, x-pipe, B&B PRT axle back and stock tune. The car dynoed 333.9 rwhp and 333 rwtq. I added Dynatech long tube system, Shaner throttle body, and had the car tuned. 335 rwhp and 343 rwtq. I'll have graphs tomorrow but the a/f was at 13.0. This is much lower then I expected. I'm have no idea what's wrong. O2 sensors seem good according to the tuner, air/fuel is good, and no exhaust leaks. The temperature today is about the same as the last time I dynoed and I used the same dyno. The car feels stronger but the numbers don't show. Does anyone have suggestions?
__________________
320HP/338rwtq
Installed Dynatechs with cats and got a tune and put down:
339HP/355rwtq
So I netted 20HP/17ftlbs.
Did you keep the rear O2s or delete them? Did you have it tuned after the install?
--Bill
Thread Starter
Drifting
Joined: Jul 2004
Posts: 1,663
Likes: 16
From: DFW Texas
CNB, are you the original owner of the car? Is it possible that, if you are not, the original owner had it tuned while still in stock form?
Your stock tune seems very high to me for the mods. I had a Blackwing, high flow coupler and Ti exhaust and peaked at 305. My tuner, also a 2002, had a duplicate of my curve for his car with a peak at 307. Both are MN6 cars. Your final seems to be right where it should be based on my experience with my header installation. I personally think you are sitting pretty good with your final results, and would tend to discard the first. Any chance the tuner grabbed the wrong baseline curve from the files?
Not sure... did you clean your air filter before each dyno run? I had a Vararam and GHL bullets and got: 320HP/338rwtq
Installed Dynatechs with cats and got a tune and put down:
339HP/355rwtq
So I netted 20HP/17ftlbs.
Did you keep the rear O2s or delete them? Did you have it tuned after the install?
--Bill
Installed Dynatechs with cats and got a tune and put down:
339HP/355rwtq
So I netted 20HP/17ftlbs.
Did you keep the rear O2s or delete them? Did you have it tuned after the install?
--Bill