is this a fair dyno pull for the little to no mods I have done to a stock 87 305?

What would the fly wheel HP be if the rear is 184?

Stock back in 87 the car only had 190 so is this good?


Rear wheel HP= 184.5
Max torque= 264.2


How much would I gain with headers and power pullies?

 

I ran a terrible 15.4 in the 1/4 at Atanta and a 9.7 in the 1/8 at a local track.
I think my rear gears are killin me........2.73....YUK!!!

oh and that was my very first time to the track an my R/T's were not to speak of.......I was imbarrased..... but oh well.

 

Attached image = unnecessary

 

Figuring about 18% drivetrain loss for an auto, (which is conservative), your at about 217hp at the flywheel. Take a few off if it's a manual.

 

A 1987 305 tpi auto put out 190 horsepower & 295 #/ft of torque at the flywheel. With a 20% loss for the Auto 152 hp & 236 torque est your number are quite good at 184.5 & 264.2 at the rear wheels.

 

What mods have you done?

As for gears 'killing' you at the track, I dont think so. I've changed gears on 2 cars (one had a pathetic 2.41 gear) and seen little gain from it.

 

Sorry, pet peeve here. At an 18% drivetrain loss he actually has 225 FWHP, not 217.

To go from RWHP to FWHP you have to divide by (1 - x), where x is the percentage of drivetrain loss. In this case it's (1 - .18) or .82.

When you just multiply by 1.18 like you did you're only adding back 18% of what's at the wheels, not 18% of what's at the flywheel.

To double check:

225 FWHP * .82 = 184.5 RWHP

217 FWHP * .82 = 177.94 RWHP

 

Actually factory ratings are at the rear wheels also. You've lost about 5 Hp and 30 #s, which is pretty good considering the car probably has 100k+ miles on it and not all dynos read the same.

A good cat-back and headers will make a great difference in the car. Don't waste your time/$$$ on pullies.

 

Last I checked they were at the flywheel. A stock L98 should dyno around 200 rwhp, an LT1 dyno's around 250 rwhp, Mustang's are around 225 rwhp , LS1 Vette's are around 305 rwhp.

The only car that dyno's what it's factory rating is (or better) are the LS1 F-bodies, but that's because GM has them WAY underrated, not because GM is now advertising rwhp.

 

Ignore me... I don't know what I was thinking!

 

I dont know why my sig. didnt show up but heres what Ive done to the engine.

how much will I get from a header install? Also what else can I do without going into the motor?

 

actually, 2.73 or 2.77 gears keep tpi in its optimal powerband for 1/4 mile runs. doesnt do you much good on the street. i went to 3.42s from 2.77 and on the street i was untouchable off the line with the autos steep first gear. once i got up to 3rd though everyone was blowing by me because tpi isnt a hi speed intake. it also slowed my quarter mile down by .1 consistantly. this was runs a week apart with no other changes.

 

i need to run my car, 3.45's with tpi 305, i'll inform y'all when it goes down the track

 

fairly stock TPI just doesnt like steep gears.Ive done all the porting intake,plenum etc,SLP simese runners, car still runs best when shifted at 5k or just a little under.With the 3:73 rear 2400 converter and 28 in tall tires it kinda runs outa steambefore the end of the quarter in 3rd,ive run my best time and MPH with it hitting 4th 100-101 in 3rd , 102.7 best in 4th.