Track times and tire size
02-28-2003, 08:44 PM
#1
Thread Starter
Join Date: Feb 2003
Location: United States
Posts: 43
Track times and tire size
I have recently ran my car at the drag strip and have a problem I'm hoping someone can help me with. My car is a 91 ragtop AOD with stock motor/heads but has a Typhoon intake,65 throttle body,73 mass air, Vortech A-trim 8lbs, 1 5/8" headers, H-pipe cat delete,24 injectors, stock converter and 4.10 gears. My first run with the car netted the following, 2.09 60' and a 13.33 at 99mph. Around 100 feet short of the traps my tach showed 6K rpm in 3rd. I had to lift fearing the 6250 rev limiter. Next run I spun from the line with a 2.13 60' but ran 13.33 at 106mph. I stayed on the throttle this time but was cringing waiting for the limiter to hit. It didn't but I need taller tires. How tall should I go from the 245/50/16's I have right now? And what changes should I see in ET and MPH? I would assume with my motor combo I should cross the line at around 5200 rpm in 3rd. Right?
03-01-2003, 01:47 PM
#2
Join Date: Feb 2003
Location: United States
Posts: 40
Track times and tire size
by just lookin at ur 60 ft times i would say ur spining alot.If you get it to hook up you will lose some rpm without losin ET unless the engine bogs.Are u runnin slicks,radials or cheater slicks and how tall are they?i run a 27 inch tall tire and a C-4 tranny with 4.11s ill look at tach next time i run it across the line.
IWISH IT WOULD GET WARM ANUFF TO GO TO STRIP HERE LOL
IWISH IT WOULD GET WARM ANUFF TO GO TO STRIP HERE LOL
03-01-2003, 08:32 PM
#3
2nd Gear Member
Join Date: Feb 2003
Location: United States
Posts: 363
Track times and tire size
it sounds like your trying to cram tooo much power into your stock heads. you should be running better than that with all of your mods. all your stuff will run a lot smoother w/upgraded heads. you will find a lot of hidden hp!!!!
03-02-2003, 01:32 AM
#4
Join Date: Mar 2003
Location: United States
Posts: 1
Track times and tire size
My tires are around 25.5" tall(regular street radial tires). With running 106mph I should have cleared the traps at about 5600rpm. Way too high for stock heads(and rockers). What I'm hoping is to go with a taller tire to bring the rpm down to around my peak(5200?). I hate to go too tall and kill ET. And go too small again and over rev. Or should I just change ring and pinion to more friendly 3.55 or 3.73? Heads are coming but a stall converter is first. The 2.1 60' times have to go!
03-03-2003, 01:59 AM
#6
Join Date: Feb 2003
Location: United States
Posts: 40
Track times and tire size
I would keep the gears ya have. Try a 26 or 27 inch tall tire.That will help hook it up and put airbags in ur rear springs,(if ya dont already) that realy helps. Remember, once you get it to hook your Rpm's will drop alittle to.Before ya start changing gears i would put some street slicks or slicks on it and run it.If ur gona put better heads on it ,you will want the gear you have now.Also,a tenth or so off ur 60 ft time will translate in alot more off ur 1/4 mile time.I have been dragracing for 16 years now and i just work on that first 60 ft the rest will come with it.Oh and a killer lite helps to.
03-05-2003, 02:51 PM
#8
Join Date: Feb 2003
Location: United States
Posts: 40
Track times and tire size
as far as engine ,not much realy bro, mostly head work (alot of headwork) decent cam>E ,,ported intake bigger fuel injecters and Nos. The C-4 trans 3000 stall and 4.11gears. But it dead hooks and that is how ya get good ETs.
03-05-2003, 08:18 PM
#10
Thread Starter
Join Date: Feb 2003
Location: United States
Posts: 43
Track times and tire size
My cam is the stock one. Some dyno reports I've read show stock cammed blower motors (w/stock heads) running out of steam at around 5200. I think you are right about just keeping the 4.10's and once I've changed heads that should allow my powerband to go up higher and pull more mph. The stock heads are definitely a bottle neck in my combo.