Dyno'd today and WTF!!
Dyno'd today and WTF!! I went up to hi-tech today and hopped on their dyno and I have to say I'm insanely disappointed! I started last year with 335/350 and after that added my intake and TB.
After the H/C and iinjectors over the winter I only moved up to 385/350. How is it possible to add all of that and only gain 50hp and not pick up any torque! That sounds impossible! There are plenty of people with just this cam that make 400/400 with cam only and no heads!
I'm pissed and now have to figure out what went wrong!
The car was running at 11.5 A/F so it was a little rich and i was getting 3 degrees of knock from 2800-6000 rpm's. I know that will throw me for some hp but i was expecting to be in the 430-440 range.
The H/C i went with are the prc 2.5 ls6 heads with a 228r cam on a 112. I know my car has more power than this, its running against vettes in the mid 400's and im keeping up!
After the H/C and iinjectors over the winter I only moved up to 385/350. How is it possible to add all of that and only gain 50hp and not pick up any torque! That sounds impossible! There are plenty of people with just this cam that make 400/400 with cam only and no heads!
I'm pissed and now have to figure out what went wrong!
The car was running at 11.5 A/F so it was a little rich and i was getting 3 degrees of knock from 2800-6000 rpm's. I know that will throw me for some hp but i was expecting to be in the 430-440 range.
The H/C i went with are the prc 2.5 ls6 heads with a 228r cam on a 112. I know my car has more power than this, its running against vettes in the mid 400's and im keeping up!
Last edited by Bjorne043; Apr 8, 2010 at 09:27 PM.
I'm an M6 so I should be much higher. And it was on a dynojet dyno. Dyno aside, since it was on the same dyno as the original dyno tune there is no way I should be at the exact same torque that i was before the internals changed
Lol. That A/F ratio is pretty far from the ideal 13ish you want to be at WOT. Also, knock can drastically reduce hp since it's pulling timing. Get those issues resolved (it'll need to be retuned if you haven't done so since adding H/C) and you should pick up noticable hp.
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my tuner said something had to have changed sine we tuned it a few weeks ago since he tumed it. he said he tuned it around 12.8. we will see what happens on saturday when we rtune it
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Make sure you have new plugs and make sure your MAF is clean. If you dynoed your car with a dirty MAF your air/fuel ratio will read wrong and through the tune out. Make sure you have a clean fuel filter too an optimum air fuel ratio is about 12.9-13.1 that is where you want to be.
I learned the hard way too.
I learned the hard way too.
it is possible that with the new injectors if you drove it around before getting tuned that it has fouled the plugs enough to drop some spark. thus creating a rich condition that will snowball. maybe check your plug wires. are the injectors new?
The plugs are new NGK TR55's, my MAF may need to be cleaned although i just cleaned it in the fall (cant hurt to do it again). The injectors were bought new and I only drove it about 20 miles to my tuner but never went above 3k rpms which i was told by many poeple was ok.
And I thought it was weird about the tune too. Everyone knows tunes dont change. He thought I that maybe i changed something since the tune, which all ive changed since is a tranny rebuild and some new tires! Those dont count!
And I thought it was weird about the tune too. Everyone knows tunes dont change. He thought I that maybe i changed something since the tune, which all ive changed since is a tranny rebuild and some new tires! Those dont count!
11.5 is not lean its RICH!! Definately some power left there from that and the knock issue. Is it actually knock or false knock? Are your knock sensors desensitized any? Maybe try different dyno just for comparison maybe?? Whats the whole setup? Heads and what cc? Cam specs? Headers/exhaust setup. Intake/TB setup? Fuel Setup? Details to help figure out problems
11.5 is not lean its RICH!! Definately some power left there from that and the knock issue. Is it actually knock or false knock? Are your knock sensors desensitized any? Maybe try different dyno just for comparison maybe?? Whats the whole setup? Heads and what cc? Cam specs? Headers/exhaust setup. Intake/TB setup? Fuel Setup? Details to help figure out problems
PRC stage 2.5 ls6 heads at 64cc with 2.02 intake and 1.57 exhaust
228R camshaft 228/228 .588/.588 112lsa
hooker 1 3/4" longtubes with hooker 3" y-pipe
Flowmaster muffler no cats
I have an 85mm MAF a ported TB and an LS6 intake
stock fuel pump with 42# injectors
I honestly couldnt tell you if its knock or false knock. The entire set up is as follows:
PRC stage 2.5 ls6 heads at 64cc with 2.02 intake and 1.57 exhaust
228R camshaft 228/228 .588/.588 112lsa
hooker 1 3/4" longtubes with hooker 3" y-pipe
Flowmaster muffler no cats
I have an 85mm MAF a ported TB and an LS6 intake
stock fuel pump with 42# injectors
PRC stage 2.5 ls6 heads at 64cc with 2.02 intake and 1.57 exhaust
228R camshaft 228/228 .588/.588 112lsa
hooker 1 3/4" longtubes with hooker 3" y-pipe
Flowmaster muffler no cats
I have an 85mm MAF a ported TB and an LS6 intake
stock fuel pump with 42# injectors
its the flowmaster muffler!!! LOL!!!! you should be making more power than that for sure.
Lol. That A/F ratio is pretty far from the ideal 13ish you want to be at WOT. Also, knock can drastically reduce hp since it's pulling timing. Get those issues resolved (it'll need to be retuned if you haven't done so since adding H/C) and you should pick up noticable hp.
my brother and i did the install. He is an ase certified mechanic and a master certified mercedes tech which i know has nothing to do with gm. He knew exactly what we were doing and we moved very slowly to make sure we didnt miss anything as well as so I could learn what we were doing. It was done more than correctly without any corners being cut
My thoughts:
-11.5 is very rich, but it's not going to pick you up 60rwhp so don't get your hopes up. (That comment is geared towards your hopes of 440rwhp)
-Driving on larger injectors for ONE mile is a no-no, much less 20+ miles. You can easily wash the cylinders out doing that. More than likely your plugs are garbage at the very least.
-Your 85mm MAF might look cute in your engine bay, but if your "tuner" hasn't scaled the MAF properly (and it appears he didn't) your fueling will be all over the place and it's doing you more harm than good. Hence the reason he's trying to command 12.8 A/F in the PCM, and it's giving you 11.5.
-Flowmaster mufflers on F-bodies flow as about as well as Obama's political views. You're easily giving up 10-15rwhp in this department alone.
Put a $35 cutout on the car to bypass the shitty muffler, change your plugs, have your tuner (if he knows how) scale your MAF properly ON THE STREET, and then tune the car ON THE STREET. Then, strap it down and make adjustments for your internet dyno #. Good luck.
-11.5 is very rich, but it's not going to pick you up 60rwhp so don't get your hopes up. (That comment is geared towards your hopes of 440rwhp)
-Driving on larger injectors for ONE mile is a no-no, much less 20+ miles. You can easily wash the cylinders out doing that. More than likely your plugs are garbage at the very least.
-Your 85mm MAF might look cute in your engine bay, but if your "tuner" hasn't scaled the MAF properly (and it appears he didn't) your fueling will be all over the place and it's doing you more harm than good. Hence the reason he's trying to command 12.8 A/F in the PCM, and it's giving you 11.5.
-Flowmaster mufflers on F-bodies flow as about as well as Obama's political views. You're easily giving up 10-15rwhp in this department alone.
Put a $35 cutout on the car to bypass the shitty muffler, change your plugs, have your tuner (if he knows how) scale your MAF properly ON THE STREET, and then tune the car ON THE STREET. Then, strap it down and make adjustments for your internet dyno #. Good luck.