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sounds like youre a bit off on ET...i went 12.00@114.2 on a 1.7x 60' with a 3300lb car and a 230 magnum cam. i had better heads but thats a BIG difference
__________________ '86 Iroc Z 9:1 358.. built th350, 3500 converter, 4.10 rear Auburn posi, Edelbrock heads, Cam Motion cam, stock suspension and Hoosier tires
B&M 3000-3500 stall
Ha Ha,yea heads came on the motor.Believe me I have been researching their replacement and waiting on the funds.
1.8 60FT is not bad for that run but somethings not right if your trapping @ 5200 with 26 inch tires, 3.73 and 3500 stall converter. And the MPH isn't great.
Be more specific with the converter because it can't be a 3000-3500. It's either a 3000-3300 or 3400-3700.
Are you running a full 1/4? Sounds like it needs more gear IMO? Or if the converter is really a 2800-3200 than loosening it will spin more RPM's and boost those numbers.
I would think that crossing at 6000-6200 would give you the push your looking for.
__________________ 1986 Camaro Sport Coupe - 383/T-350/3k stall/4.10's
10.8cr, AFR 195's, victor Jr, Pro Systems 850.
COMP XE-284-H (241/246 @ .050 W/ .537/.540 lift)
Hooker 2210's (1 3/4) W/ 2.5 exhaust and Flows Motor all forged and studded for Nitrous
I will also be changing rear gear.
I am stuck between 4.10+4.33,any suggestions?
I will also be going to a 275-60/15 tire.
If this is track only, buy some slicks. Even if it's just street/strip, buy some slicks and have them mounted on some lightweight rims for strip use only.
Gear ratio depends on the height of the tires. You want a gear ratio that will get you across the finish line at or just after your shift light comes on when in high gear (not OD).
You've only shifted at 6400. It's possible that cam still makes power above that. Since you have a TH350, high gear is 1:1. You want to cross the finish at 6400-6600 rpm. Put the tallest tire you can possibly fit under the fenders then pick the gear ratio to give you the proper finish line rpms.
__________________
87 IROC-Z
All engine, no power adders! Bests: 9.348@144.71
I incorrectly typed my shift point,it was 5400 not 6400.
Went to dyno yesterday and cam peaks @5400,torque and hp meet at 5300.
Torque starts to fall fast but HP falls slowly to 6000,as far as we pushed it.
Max rwhp 250,after 3 jet changes( my tune was lean )gained 30+HP
max torque 270
Too big of carb. Step back to a 650 and you'll get a bunch of bottom-end back.
Until I went to a large enough cam to make power over 7k, the 650 made more power and the fuel curve was a lot better(airflow vs venturi size). The smaller carb is more responsive as well, especially with taller gearing/tighter converter than optimal. - The large venturis is also likely why you were lean; not enough signal to pull the fuel properly.
Past that, put better heads on it and you'll make a bunch more power.
Actually, they met at 5252. That's because HP = torque x RPM / 5252
Yep. Unless the dyno is using a screwed up correction factor(to sway numbers), they always meet at 5252. - HP is just a mathematical calculation based off of the amount of torque measured vs the rpm band.
Yep. Unless the dyno is using a screwed up correction factor(to sway numbers), they always meet at 5252. - HP is just a mathematical calculation based off of the amount of torque measured vs the rpm band.
ok, did not know that,print out I was looking at was divided in 500rpm increments and I was rounding it off.
Interesting that your torque and HP almost peak at the same RPM.
For best performance, you would launch at or just below your peak torque. That's what's needed to get all that weight moving as quick as possible. Without a transbrake, you won't even be able to reach the true stall speed of your current converter. You shift around where the HP starts to drop off and the rpms should drop to the beginning of the HP curve. Torque gets you moving. HP gets you down the track.
You'll probably be quicker if you shift around that 6000 rpm range. It will also allow you to stay in each gear a little longer but your finish line rpm may end up being lower. This just means you'll need a little deeper gear like 4.10. That will probably get you that 12 second timeslip.
Torque peaks @ 4200
HP peaks @ 5400
(high gear@3800rpm,then flooring it)
Dyno guy recommend 5900rpm shift point.
My summit mini starter just took a dump on me,chewed up my flexplate a bit,so I just ordered a Powermaster 9100 and a TCI flexplate.
So much for racing tonight.
Finally got to the track after the dyno tune,been chasing an electrical issue,ended up being the master shut-off switch.
Anyway best run of the night
12.76 @105.5
1.75 60'
6000rpm shifts
went 12.83
12.89 short shifted second
12.79
12.76
and a 12.85 in that order
The first and last pass the engine was a little cooler,seems to like to run at 175-185.
Still only at 5500rpm at the end
