When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Not sure if this is the right place but here it is. I feel like my car is putting out low power with the mods it has right now even with it being on a mustang dyno. It’s a m6 98 Trans Am. My tuner said she doesnt like much timing due to the load and the low gearing(3.23) doesnt help it get up on rpms on the upper gears...so could gears be the only culprit here?
Made 346hp at 5871 with these mods.
Torquer V2 232/234 .600/.600 114 LSA cam
MTI Carbon fiber lid
k&n filter
Stock maf
Accordion bellow
FAST 92mm Intake Manifold
FAST 92mm Big Mouth LT throttle body
PRC 2.5 5.3L 60cc heads
7.400 pushrods
LS7 lifters
Dual valve springs
Ported LS6 oil pump
LS2 timing chain
NGK TR55 spark plugs
MSD 8.5 wires
Racetronix fuel pump 255
Bosch O2 sensors
FIC 80lbs fuel injectors 850
Flowtech longtube headers
3” Pacesetter Off-road Y-pipe
Dynomax bullitt
Cut out before the axle
40 series muffler FlowMaster muffler
Tremec T56 Magnum (2.66/1.78/1.30/1.00/.80/.63)
RAM HD clutch
HAWKS billet Short throw shifter
RAM billet steel flywheel
3.23 gears
Ill have to post the underside tomorrow when I put it up on a lift to get a clear picture but here is the graph if this provides better data. Cut out was closed, I was told it wouldn’t make a difference, which I could was odd
yeah it was the only time that it got tuned. This was in texas, I'll have to look for a new tuner out in virginia now. Also, This gives me an excuse to do a true dual setup over the axle. I had this exhaust for over 10 years now when I was a teen, so my choices weren't wise back then.
Spin to 6300-6800 rpm huh? would having my tuner only bringing it up to 5800 explain why driveability is good? He knew there was plenty of power left on the table but advised me to change my gears first.
Do you normally cruise at 5800? Sarcasm aside....it doesn't matter if you rev it to 6k or 7k, drivability is about idle and part throttle not max revs.
On a LS the runners on the intake will generally give you peak power at 6300 unless you do something really off the wall. If you make peak at 6300, you likely will want to shift in the 6800-7200 range.
I would stall before gear. 3.23 gear usually means auto
On a LS the runners on the intake will generally give you peak power at 6300 unless you do something really off the wall. If you make peak at 6300, you likely will want to shift in the 6800-7200 range.
I would stall before gear. 3.23 gear usually means auto
Copy, sorry forgot to mention it’s a rear end from an auto car with that gear
...Spin to 6300-6800 rpm huh? would having my tuner only bringing it up to 5800 explain why driveability is good?...
WOT tuning vs Driveabiltiy tuning are two different things.
It sucks - but I assume this is your first experience on a custom built setup/going to a dyno tuner. Which is okay, most all of us have small little issues along the way. Now you know.
There are so many "dyno tuners" out there, that have absolutely no desire to tune someone else's car as well as the owner would want to tune his/her own car. When going to the dyno, the worst case scenario (and the most common one) is at the very least having your WOT area tuned, with a dyno sheet having your power number/curve. The best case scenario, is a tuner that actually bothered to tune most important parts of your ECM, as well as driveability.
Your tuner didn't even do the worst case scenario for you... refund refund. It's too bad you're not there any more, I'd be hollering for a proper tune if you already dished out the cash. (Unfortunately, this tuner doesn't seem like he knows enough to even do that anyway)
it is what it is - and in this case, it's a learning experience.
In my opinion I think your valves are staying open and not making any compression. 7.400 is a standard stock size pushrod you probably need like a 7.325 or 7.350 but you would need to measure to find out.
Thanks for the inputs. I follow a lot of the proven builds here and got ideas for my own, and yes this is my first built car. I would’ve thought at the very least 400whp but I’ll check the pushrods and maybe even change a couple things with my setup before taking it for a retune local.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
Down on power with H/C/I 
