TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
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
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 .
__________________ PROJECT UGLY DUCKLING
1989 10:1 353 L98Edlebrock base and runners ( really ported)ZZ4cam ,1 3/4 SLP shorties 083 heads ...cleaned up andstuded w/1.52 rr , LT4 valve springs and retainers and a 3 angle valve job
suspension mods (Hotchkis LCA's PH bar, KYB shocks and struts)
T-5 3.73
T-62 turbo to be installed next ...Exhaust clip ...gota let it load.... http://media.putfile.com/My-exhaust-clip
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"
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.
__________________ 1988 Trans Am 355. 33,000 original miles.
355ci 10:1, Holley 750DP, Summit Stage 2 intake, AFR 180cc Street Eliminators, Comp Cams XR282 HR10, MAC shorties, Mufflex 4" exhaust, Circle D 3500 stall
Best ET: 12.26@108.44, 1.67 60ft
Best MPH: 12.57@112.5, 2.0 60ft
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.
__________________
86 IROC, Superram 383, TKO 600, C4 IRS
89 GTA, L98, A4. T56 swap pending
91 TA LB9/T5 (R.I.P)
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.
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.
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.
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.
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.
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.
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.
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...
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.
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."
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 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....
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.