Skip to main content ↑ ↓
Topic: New best (Read 5237 times) previous topic - next topic

New best

Went to the track today with my 3700lb fatty Thunderbird ran as follows:

60': 2.108
330': 5.902
1/8: 9.075
MPH: 77.31
1000: 11.820
1/4: 14.129
MPH: 98.01

By reducing my best 60' of 2.2x last year the car picked up .1 and 1.5+ MPH on street tires. Traction, traction, traction is the key. I need to rebuild the 8.8 I've got in the garage and slap a set of drag radials on this thing. If I cut a 1.8 60' fatty would be in the mid to high 13s at 100+ MPH. I can only imagine what drag radials paired with a better flowing intake and more aggressive cam would do.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

New best

Reply #1 –
Congrats.

 Your drivetrain is very nicely put together.  Very similar to what Im planning.  Those PI converters arent cheap!
Mike

New best

Reply #2 –
I need to rebuild the 8.8” rear I've got sitting in the garage before I run the car anymore. I'm afraid to put drag radials on the 7.5" rear because I’m pretty sure it’ll break. With the 225/55/16 Firestone Firehawk GTs on the car right now I spin for about 15-20ft off the line leaving at idle. I tired leaving against the converter (took it up to just over 2000rpm on a 2800rpm stall) just for fun last night and that didn’t work at all. The car spun 40+ feet down the track and went sideways. I went 15.5@96.1 on that run. When I revved the engine up to leave against the converter it pulled really hard. The tires weren’t up to the task at all though. With a set of drag radials and skinnies I swear the thing would try to lift the front tires. It has a stupid amount of bottom end grunt for a small V8.

Those PI Stallion converters are not cheap (I think it cost me ~$650 for the 2800 stall in mine 3 years ago) but man do they make a big difference. Anything over 1/3 throttle on the street and the rear tires light up. The converter gets the car into the power band really quick and it pulls hard off the line. They are worth it.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

New best

Reply #3 –
Is it still direct drive/lockup type?

What are you using for tranny cooler?
Mike

New best

Reply #4 –
you should be fine with the 7.5 for now.. ive been 11.40 with my bone stock 7.5 n been a best of 1.58 60ft with slicks an also drag radials.

New best

Reply #5 –
Tire is everything if your chasing that time slip

New best

Reply #6 –
Quote from: mcb82gt;422034
Is it still direct drive/lockup type?

What are you using for tranny cooler?


It's a non-lockup PI Stallion. I don't remember the part number fo the trans cooler but it's one of the bigger ones Hayden makes. I can contact the guy who built the trans (I got it from him) and see if he can tell me what the part number is.

Quote from: slowbird;422036
you should be fine with the 7.5 for now.. ive been 11.40 with my bone stock 7.5 n been a best of 1.58 60ft with slicks an also drag radials.


I could chance the 7.5 but I've got an 88 Cougar XR7 8.8 sitting in the garage right now. I might as well stick some 31 spline axles, a 03-04 Cobra spec Traction-Lok, and 3.73 gears in it and have some fun. That way I won't have to worry about breaking it.

Quote from: STANG8U;422040
Tire is everything if your chasing that time slip


Tell me about it. No traction means poor E.T.s and low MPH. Every time I cut the 60' on this car down .1 second it reduces the E.T by .1-.2 seconds and gains 1 MPH in the quarter. I need some sticky tires.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

New best

Reply #7 –
Quote from: thunderjet302;422046
It's a non-lockup PI Stallion. I don't remember the part number fo the trans cooler but it's one of the bigger ones Hayden makes. I can contact the guy who built the trans (I got it from him) and see if he can tell me what the part number is.


Thank you, but it isnt necessary to go to that work.
Mike

New best

Reply #8 –
slowbird, do you have a spool or an aftermarket diff? I heard the weak link in the 7.5 are the spider gears in the diff. If I could do it over again I might have stayed with the 7.5 because I hear there is less parasitic drag (to hell with stopping, I don't need discs!)
home ported E7's, HO intake, 93 Tbird cam, 65mm tb, Shorties, dynomax lers, TC 3.73 rear, Mach 1 springs, Bauman shiftkit, epoxy mod, SD, 3G alt, black magic fan

New best

Reply #9 –
Crash225 nope none of that bone stock.. I will eventually upgrade to a 8.8 but I am  just a broke kid on a budget lol
 

New best

Reply #10 –
Playing Around with some number and calculations makes the case as to how much more power aftermarket aluminum heads are worth over stock factory Ford iron heads. When the car was set up the same as it is now but with GT40P heads the best time I got out of it on street tires was 14.65@93.29 with a 2.3 60’. The best with the Edelbrock Performer heads was this last run I made, 14.13@98.01 with a 2.11 60’. On MPH alone the car picked up almost 50 HP from a head swap with no other changes. I think that’s pretty good.

Here’s where it gets more interesting. The best run with GT40P head was made in almost perfect weather, 53*, 40% humidity, a 30.8 baro. The track I run at is 637 feet above sea level. Using a DA calculator the conditions on the best GT40P run equated to running the car at almost seal level, about 60 feet. Where I live it’s hard to get better conditions than that. The best Edelbrock head run came on a 69* day with 72% humidity and a baro around 29.4. Using a DA calculator that comes out to about 1400 feet above sea level. Correcting a DA calculator the 14.13@98.01 turns into a 13.9@99.4 at sea level.

I went online to try and figure out how much power the engine in the car is making. Now I ran the car on a dyno when it had the GT40P heads for fun once. It made 232 rear wheel horsepower. Plugging the best run it had into an online rear wheel horsepower calculator gives a number of 234 rear wheel horsepower so not far off. Dividing by .80 (an AOD combo usually has ~a 20% drive train loss) results in 293 flywheel horsepower, which is inline with many GT40 head/intake combos which make around 300 average flywheel horsepower. Now if you plug the numbers from the best run with the Edelbrock heads into the same calculator it comes up with around 270 rear wheel horsepower, which equates to almost 340 at the flywheel. If you use the condition corrected numbers it goes up to 283 wheel and 354 flywheel horsepower. All this means is that again the Edelbrock heads were good for some where between 40-50 horsepower over the GT40P heads.

With the Edelbrock heads I’ve also learned that 60’ plays a huge role in how fast the car will go. On the same day I ran 14.13@98.01 with a 2.11 60’ an hour earlier (same weather conditions) it ran 14.33@97.02 with a 2.2 60’. On average, with my car and many others, a .1 second reduction in 60’ got me .2 seconds and 1 mph increase in trap speed. I can guess that if I cut the 60’ down to 1.9 the car would run around a 13.8@100+mph under the same conditions with no part changes. Long of the short is the car needs sticky tires.

If I did it again I would probably run a set of Trick Flow 170 TW heads or AFR 165 heads. The flow better than the Edelbrocks and probably would have gotten me ~25 more horsepower as the car sits. I got the pair of Edelbrock Performers for $800 new in the box, which is cheap for a pair of USA made aluminum SBF heads. Now if I got them through Summit they cost right around the same as the TW 170 or AFR 165. Sometimes when you get a deal you make it work ;).
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.