My LOW dyno'ng car. Help please.
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From: Sioux Center, Iowa
My LOW dyno'ng car. Help please. I do not have the dyno sheet to post to show you but my numbers before tuning were 342 rwhp 348 rwtq and my car ran like ***. After 45 minutes of data logging with auto tap driving around and then 7 pulls on the dynojet using LS1edit getting it all perfect the highest my car would put out is 355 rwhp and 352 rwtq. A/F ratio is a solid 12.8 and timing was on perfect with no knock anywhere and the car runs perfect after tuning now, it idles at 700 with A/C in 90* days no problem. What's my problem?
Before TR224 cam, comp springs, hardened rods, LS6 intake manifold: 328/337
After with stock tuning: 342/348
LS1edit tuned: 355/352
*also car before tuning car made peak power at 6K rpms and would drop off fast, but now it pulls 355 rear wheel straight to 6500 rpms before dropping off. So i gained about 30 rear wheel from 6000-6500 but my numbers SUCK for my mods.
Before TR224 cam, comp springs, hardened rods, LS6 intake manifold: 328/337
After with stock tuning: 342/348
LS1edit tuned: 355/352
*also car before tuning car made peak power at 6K rpms and would drop off fast, but now it pulls 355 rear wheel straight to 6500 rpms before dropping off. So i gained about 30 rear wheel from 6000-6500 but my numbers SUCK for my mods.
Honestly, I would take off the SLP MAF and go back to stock and get it retuned. I bet your numbers will go up if you're tuner is good tuner. Personally, I've seen too many problems with guys running aftermarket MAF's.
Originally Posted by JakeY2KZ
Honestly, I would take off the SLP MAF and go back to stock and get it retuned. I bet your numbers will go up if you're tuner is good tuner. Personally, I've seen too many problems with guys running aftermarket MAF's.
Originally Posted by nexvctm2001ss
Why is that?
What about adding a cut-out ? I mean, you never know if your exhaust could be holding you back. It's always different with different cars. It's about 30 bucks for a cut-out and 30-40 to have it installed. Give it a shot ?
Launching!
Joined: Mar 2006
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From: Hinesville, GA
Originally Posted by JakeY2KZ
Honestly, I would take off the SLP MAF and go back to stock and get it retuned. I bet your numbers will go up if you're tuner is good tuner. Personally, I've seen too many problems with guys running aftermarket MAF's.
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Originally Posted by WS6RED2002TA
I here people say this alot, but I would look else where. I have the SLP massair for almost two years now and never a problem. My numbers are in the sig and thats is without the ported throttle body. However swapping mass air sensor is very easy to do so I guess you could give it a shot. Good luck.
I mean with my mods I put down 348.7 rwhp through stock manifolds, no cam, no ported TB, and no underdrive pulley. I got a cam waiting to go in and I'm expecting 380rwhp or so untuned and 400+ rwhp after a tune.
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i would liek to know what kind of dyno this is as well. also, what is your spark advance peaking out a? i agree that aftermarket maf's in general can get ugly to play with, but your a/f ratio should be a good indicator of a crappy reading mass air flow.
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From: England
Originally Posted by NW Iowa WS6
The dyno was a Dynojet. My air fuel ratio was 12.8 solid. My pushrods are part of the Thunder Racing cam kit.
First off how does the car drive? If it drives right then 9 times out of 10 it is right.
If the SLP MAF has been tuned correctly it probably isn't an issue, although I'd still opt for a stocker. However 20rwhp isn't being lost via it.
A cutout would be a totally pointless option. The exhaust is not an issue and will be flowing sufficently. Also a cutout would not yield 20rwhp.
Take you car to the 1/4 and see what it runs, you terminal speed (trap speed) should be a good indicator if there's anything amiss.
Who installed the cam? If it's a degree out that may cause an issue. But if it's making power up in the high rpms on the dyno this is unlikely.
Lastly go and re-dyno the car BUT on a different dyno to get a comparison.
You say it was on a Dynojet? Well obvious things to consider are, was the dyno calibrated (many are not), was it a newer load bearing style Dynojet as they will give lower but more accuratre numbers. Was it corrected to SAE and what level graph smoothing was being used? Also what gear was used for the dyno runs, it needs to be a 1:1 ratio (or as near as possible) in a M6 that should be 4th. If it's in a different gear it will lower of raise the HP number depending on what the ratio of the gear is.
Remember a dyno is a tool and not primarily a measure. The numbers are often pretty meaningless.
Also if it wasn't being corrected, correctly. What where the weather/atmospheric conditions like?
Thread Starter
11 Second Club
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From: Sioux Center, Iowa
The car drives perfect and feels really good but the numbers say otherwise. I dynotuned at DynoTune USA from Watertown South Dakota. I do not know if the dyno is calibrated or not and the temp outside was about 60* and elevation is about 1400 ft. above sea level. I installed the cam myself and I got the dots lined up dead and yeah it holds my peak hp and tq numbers all the way 6500-6600. I also did do a baseline at another dyno shop at the same elevation but at about 90* outside and the numbers were 341/346 opposed to my pre-tuning 342/348, the car was also dyno'd in 4th gear as well as it should be. I have not ran it at the track yet though, but it's not a low number dynojet because another cam only 228/228 .581/.581 112 with same bolt ons as me there put down 389/376. My numbers are not SAE corrected.
Last edited by NW Iowa WS6; Jun 19, 2006 at 12:01 PM.
