The other day I decided to put my 1991 Firebird Formula 305TBI on a chassis dyno to see how much HP and TQ it has. The operator made three, no, two passes on his Dynojet and gave me a single piece of paper with a graph of the HP, TQ and Air/Fuel Ratio for the two runs. No other data, no suggestions, no comments except to say that I have a strong car and that the air/fuel ratio is really flat. The HP was 182.92 and the TQ was 235.75, at the rear wheels of course. The stock HP is 170 and the TQ is 255, I presume at the engine. I told the operator that I was disappointed with the results, but he said "no, you have a really high performance car". I paid him his money and drove off in my car.
I have been modifing my car for many years and put a lot of money in it to increase performance. It runs 1.94 (0 to 60ft), 8.91 (1/8 mile) and 78.4 (1/8 mile) on street tires. Included here is a list of my mods and a copy of the dyno runs. Does this look like a car with 182HP and 235 FT TQ? Could I have my car so de-tuned that it really does only have the HP and TQ that the chassis dyno states? Is the dyno malfunctioning? Is the dyno operator dishonest?


1991 Pontiac Firebird Formula 305 TBI
Purchased 7-16-90.
58762 original miles 11-13-2006).
Synthetic oils and grease.
Emissions legal.
Matching numbers.
Maintenance records from day one.
All modification receipts with dates purchased, dates installed and price paid.

Modifications
Edelbrock TBI Performer intake.
TBI modified by Turbo City to flow 565 CFM.
TBI bonnet 1-inch spacer.
Auto Meter air/fuel ratio monitor.
Crane roller tip/needle bearing fulcrum Gold Race Rockers.
SLP cam - Dur. @ 0.050 0.209/0.214, Lift 0.471/0.490, 112° CL.
K&N fender mounted air filter.
SLP Tri-Y 1 5/8th-inch headers MCCI coated inside and out.
Flowmaster two chamber cross flow muffler.
Custom 3-inch Cat-Back exhaust system.
Random Technology 3-inch catalytic converter.
Auburn posi.
Richmond 4.10 gears.
TA Performance Products rear end cover.
Dacco 3000 flash stall torque converter.
Hayden transmission oil cooler.
Darrel Young 700R4 TV Valve 0.521.
Fairbanks 2-4 Billet Servo (700R4)
B&M megashifter.
Paxton supercharger (modified for 6.5psi boost).
Adjustable vacuum controlled fuel pressure regulator-external to TBI.
Corvette electric fuel pump-inside tank.
Vacuum-Boost & Fuel Pressure gauges-mounted inside car (isolator mounted on firewall).
Hypertech Thermomaster chip (primary), ADS custom chip (secondary).
160° thermostat.
MSD 6AL ignition.
MSD Blaster 2 coil
MSD tach adapter.
MSD dash mounted adjustable timing control.
MSD Pro-Billet Distributor.
Bosch platinum plugs.
Accel 8mm spark plug wires.
Trunk mounted battery.
BF Goodrich Radial T/A 265/50 HR15 Front.
BF Goodrich Radial T/A 275/60 SR15 Rear.
Crager Drag Star polished aluminum wheels, 15x8.
Monroe adjustable air shocks, rear.
Front Stabilizer Bar Link Kit, AC Delco High Performance
South Side Machine weld on Sub Frame Connectors.
Cloyes double true roller timing chain set.
Cyberdyne speedometer calibration box.
Mildly tinted windows.
Repainted stock Bright Red w/BASF basecoat-clearcoat 5/2003.
Headliner-replaced.
Optima Battery, 800 CCA.
Air Conditioner R134 Retrofit

Sorry, I can't paste the dyno chart.

Thanks,
Don

 

I thought you were doing good as I was reading down the list. Then I got to Paxton Supercharger and a couple of more items. So yes I would say the results are way low. Something is way wrong. You probably need a good custom dyno tune. Not sure how the ADS custom chip fits into things. Was it mail order?

 

Yeah I too have to say that your tune is seriously killing you.Get a custom tune and you WILL REALLY wake that car up.

 

Keep in mind your running a 15 year old 60,000 mile bottom end. its not brand new... Not real old either but still i think you get the point, it would be pushing less than stock #s (sorry , i just hate it when people assume their motor is pushing XXXhp which was what the motor pushed 20 years ago...)


I would also have to question the state of tune, at minimum its got to have a chip set up for a basic similar system. Not just a generic mail order POS!

Also your numbers come out to approx 220hp/278ft/lb at the crank, which your right, 6.5psi boost should be getting you more than 40hp/20ftlb even on a dead bottom end...

Whats the compression like? Whats the compression ratio?

Maybe you nuked a couple slugs if you got a bad tank of gas...

 

Where do I go to get a custom tune and what all will it do?
BTW, the ADS chip is not leagle on the street, so I only use it occationally, but it doesn't seem to make that much difference.

 

Well you could take a shot at tuning it yourself (read tech articles and stickies) or im sure some people here can point you in the right direction to find a local or semi-local guy that can tune and burn chips for you.

 

Get an EBL.

Its well worth it, lol, its barely more than those completely worthless chips you have already.

Fixes alot of the known TBI issues and some unknown ones too.

Rbob has a very sold product.

Anyone running one who does tuning will vouch for it.

later
Jeremy

 

I have heard a little bit about EBL. Do you have EBL? I would like to know more about it and what all it will do. Where can I get the info and the product? How do I get in touch with Rbob?

Thanks,
Don

 

WOW. I cant believe that one. Def. need a tune....WOWSER. This is just shocking to see. Your going to have a WHOLE NEW CAR when you get it properly tuned. LMAO. Your really going to love a tune, and how much a good one can make a car run.