sooo there was a dyno day at the local dyno place so decided to see what the formula would put down since the last time i was there...

Car
1991 Firebird Formula, 305 TPI, T5

History

Bone Stock other then WAI and TB bypass she put down 206 RWHP, 291 RWTQ

so throughout the year ive done a few things here and there... mostly free mods... Ported Plenum,AC removal, Quarter in FPR (bumps fuel pressure about 4-5 PSI), Custom CAI, Advanced base timing to 14 degrees (94 octane in tank,160 T-Stat,Long Tube Headers and that just about sums it up... onto the results

First Pull

259.4 RWHP @4510RPM , 341.3 RWTQ @3430RPM
AVG HP from 2200-5500 = 213.3 HP
AVG TQ from 2200-5500 = 300.7 FT-LBS
SAE J1349 Corrected

Second Pull

261.0 RWHP @4550RPM , 341.8 RWTQ @3495RPM
AVG HP from 2200-5500 = 214.4 HP
AVG TQ from 2200-5500 = 293.6 FT-LBS
SAE J1349 Corrected

overall i am very pleased with the results... much higher then i expected for the little 305

i'll be going back in a couple weeks once im done installing my new cam and then come spring time... the 305 is getting replaced with something a little more potent

 

Nice numbers! Any track times after the mods that were done?

 

That is awesome for a 305! What cam are you going with?

 

Those are definitely impressive numbers for a 305 with those mods, always good to be surprised (ina good way) when you run it on a dyno.

 

strange , they sound Awufully high . A guy on here ( stiffler) had all the free mods SLP ehaders , SLP runners , pullies and it was a 1992 SD setup ( tunned . He got 227 rwhp . Wonder about the dyno ? What kinda was it .... where they corrected numbers ? People got a reputation of running high there . Because I find them a bit hard to swallow . But way to go regardless.
Aslo you don't need 94 octane gas
I gto only 251 rwhp with the stuff in my sig ...see what I am gettign at ? This is on a brand new motor .

 

Never thought of them not being corrected numbers, good call. Btw, what makes your engine a 353?

 

First Pull

259.4 RWHP @4510RPM , 341.3 RWTQ @3430RPM
AVG HP from 2200-5500 = 213.3 HP
AVG TQ from 2200-5500 = 300.7 FT-LBS
SAE J1349 Corrected

Second Pull

261.0 RWHP @4550RPM , 341.8 RWTQ @3495RPM
AVG HP from 2200-5500 = 214.4 HP
AVG TQ from 2200-5500 = 293.6 FT-LBS
SAE J1349 Corrected


dyno was a dynocom

no track times yet... unfortunetly the day i wanted to go it rained and it happened to be the last T&T night of the season... but i have had a few run in's with some mid 13 second rides and none of them could pull away from me and a few i've acctually pulled away from..

The cam im going with is a 220 224, 270 274, .474" .474"

 

That aint right.

Its too high period.

Nothing u can say would make those numbers make sense from a set of long tubes and a ported plenum.

The motor could have been swapped for a 350 or has cam/head work done to it that you arent aware of.

To verify for some giggles, find another dyno near you. Dont say anything about running it prior and run it again at another location.

U might find yourself suprised, not in a good way either.

later
Jeremy

 

Not all dynos are made equal. I'm sure on a mustang dyno he'd have seen more conservative numbers.

That being said, if, on the same dyno he gained almost 50 rwhp/tq with those mods then obviously he's doing something right, regardless of what the baseline/final numbers were.


Remember, TPI engines were notorious for being down or up on power from what's advertised.

 

Yes, that is a very high number, were you in 3rd gear or something? Your rear wheel numbers say your engine is making around 325hp which is not possible with the mods you have. Go to the track and tell us your trap speed and well tell you how much power you have.

 

Prob 20 over.


Yea those numbers are skyhigh.
----------
BTW gotta graph?

 

Yeah those #'s are high to me also. I had my 305 to a mustang dyno on
8-27-06
Everything I have done are in my sig.
max:211 torque, 175 Eng Power AFR 14.2
where the hp crossed the tq was at around 4300rpms (on the graph)
Pull was in 2nd gear
my peak HP was at 3222rpms (175hp)my peak TQ was at 4800rpms (211tq)

And I thought that was really low for what I have done. I'm taking it back in the Spring, they need to fine tune it just a little bit more. I think the afr is a little high.

 

14* of timing? How did the knock sensor NOT pull a ton of timing out of it?

 

Bone Stock 1/4 Mile Time was 14.92 @ 92.5 MPH... works out to roughly 205RWHP?... i dyno'd 206

Free Mods + 10 degree's base timing + 91 Octane(no headers yet)
1/4 Mile = 14.3 @96.6 MPH

works out to what roughly 230 RWHP in a 3450LBS car? (weight with me in it.. i weigh 140lbs... and my car has some weight reduction)

now i added the headers, did some more port work to the plenum other then grinding down the walls behind the TB, advanced the timing a little more.. and put in 94 octane in the tank....annnnd now i got those numbers...oh and the pull was in 4th gear like it should be...

 

4th gear? I dont see too many pulls in 4th gear. The gear ratio is a little low. But I did notice you have a manual. I never dynoed a car with a manual.

 

That seems very low for your engine.

I can pretty much back up the original posters dyno numbers.

I had my 312 on a Mustang dyno a couple of years ago.

305 bored .040, Flattop Pistons, Bowl Blended 601 castings (52cc for 10.5:1 compression), Stock 929 350 cam, 1.6:1 roller rockers, 1 3/4 x 3" headers, dual 3" exhaust, Holley Projection intake, 454 TBI unit, 454 injectors. The third gear pull made 240 RWHP @ 5,000 and 340 RWTQ @ 3,300. This is through a 700r4 w/2,000 rpm converter and 3.08 gears.

 

You're supposed to dyno the car in the gear that is 1:1 ratio, or direct drive. That's third gear on an automatic and fourth gear on a stick shift. Also, stick shift cars will dyno higher than automatic cars, because the automatic trans clutches will slip and eat up more of the horsepower than the clutch and gears in a stick shift.

 

i agree, those numbers are awfully high. something doesnt sound right.

your definately gonna need to get track times or dyno it again elsewhere.

but goin from 92.5mph to 96.6 seems like a very respectable gain for just free mods/fuel pressure and timing.

My L98 was doing 97-98mph with full exhaust and gears in warm weather. L98's always ran stronger than 305's

 

Jethawk congrats on those great numbers!!! It gives us 305 guys hope and something to aim for.

But one question, you said you got 206 and 291 bone stock, but I remember in an old post, you said you got those numbers with the TB bypass and a cold air intake.

But again, I don't mean to rain on your parade.

 

that is correct... that was version 1 of the intake the filter was in the stock location so all it was, was bigger tubing... the cold air intake i have now goes all the way down into the fender... and yes i did have the TB bypass.. i'll edit my post...

i'll also scan my graph and post it when i get back from work later on tonight! i'll even throw in my time slips from my track runs aswell...

 

Correct, a proper dyno pull is done in whatever gear is 1:1 ratio, 700r being 3rd, T5 being 4th. BUT, stick ccars dyno higher because it takes less power to turn a manual trans, and beacuse the clutch doesn't slip. Auto trans take more power to turn (more internals, plus the pump), and the tq converter also eats some, unless it's locked-up, which requires a very good converter clutch. - The only way the clutches slip is if your trans sucks......

- as for the original post - Congrats! - Some of these car just made more power than others.

 

Even consideirng less loss with a manual then with an auto I'd be delighted to see those numbers out of my 305 and it's got home ported heads, Megasquirt ECM and a cam throw into the mix. Something is seriously amiss there.

 

Jethawk, whats the deal with putting a quater under your FPR???? Never heard that one, I must sleep under a rock....Thanks, Tom

BTW, what does it cost to dyno your car?? (Average)

 

A quarter bumps the static FP, sort of a stop gap measure for those of us that don't have an AFPR or those who can't tune a SD chip. A Speed Density system is largely "blind" to the changes you make on the system, so you have to get more fuel to it in one way or another. Ideally the quarter will get the AFR closer to "optimal."

 

Wow, I gotta try the quater thing.Who all has done this???...Does it make any "Real world" difference??? Thanks, Tom

 

Here is the Dyno Graph

http://i14.photobucket.com/albums/a327/jethawk/Dyno.jpg

Here is my best run from a T&T night i'm car 306(before the headers,10 degrees timing and 91 octane)


Highest MPH of the night... same night as above ^

 

something seems way off? My L98 Formula full bolt on car made 251 RWHP , about 10 HP less then yours. I have made 1/4 mile passes of 13.21@104.XX. About 1.2 seconds faster then your passes. You should get your car dynoed at a different shop.

 

those passes were before the headers, less timing and 91 octane.... i havent been back to the track since i've done the headers,more timing and more port work to the plenum

 

those mods might be good for .25 at best.... Get some new 1/4 mile passes and def get it dynoed some where else.

 

if the tracks are open again before i have everything ready for my swap.. then i'll go and run it....buttttt if i collect all my swap parts and the tracks arent open then im not gonna wait... cause i want my swap done as soon as i can get started on it so i can work all the bugs and stuff out...

oh the new engine going in will be a LT1 with LT4 Hot Cam, with Lightly Ported Heads and intake... it ran 12.8's @ 105 in a 1998 full weight S-10 and 11.8's on a 100 shot....

 

96.6mph trap seems more like a 225-230whp car

 

exactly.... those 96.6 MPH traps were with just free mods, a little porting, fuel pressure and timing

now add headers, more timing, and more port work... i dont see why a gain of 20-30 more RWHP isnt possible...especially with how restrictive the stock manifolds are...

 

Impressive numbers, I have a 305tpi, and those numbers seem freakishly high to me as well, but anything is possible. I guess the Earth and Moon were perfectly in line when that baby was slapped in the car. Congrats. It's kinda funny also how the skeptics come out in full force calling b.s on the dyno. No matter what you just can't ever satisfy some people.

 

I just dont see how those #s are possible with those particular mods. A 305 or motor with equal cubes with aftermarket heads cams and intake will produce about the #s on that dyno sheet. I not calling you a liar I am saying the dyno must be off.