My eventual Goal 12.99

D-bird

Registered User
So I'm a poor college kid who had too much time and not enough money. I was thinking with a goal of 12.99 would 3.90 rear end gears be appropriate....according to my calculations that'd put the end of 3rd gear at approx 6000rpms@106mph. I checked the Top SC list and 106 mph seemed good for a 12.99 pass, right?

just a fyi, my car is a 94 auto with 2.5 inch exhaust w/magnaflow x-resonator, and borla mufflers.

How close to my goal do you think these mods would get me?

Underdrive pullies
Jackshaft pully
90mm maf
85mm t-body
MP inlet plenum/port my plenum
port blower
gasket match intake
minor to moderate head work (no reshaping exhaust ports)
cam
high stall locking torque converter
ported exhaust manifolds
and of course a tune

or would it be cheaper easier if I want AR route and added from there to get to my goal?


Questions, Comments, Concerns??? I'd be more then happy to hear them all.

Darrel
 
One more quick thing with 3.73s my calculations for 106mph would be approx. 5700 rpms. And for comparison 6000rpms with 3.73s would be approx. 111.5mph.

-Darrel
 
for one thing the locking convertor isn't an option for you nor would you want it. The 94 will lock the convertor when it feels necessary. But if you are accelerating hard it remains unlocked.

You will need a trac-lok to install in the rear end if you want to get off the line and not spin one tire like your car will now.

3.73's would be perfect for the 4r70w trans. With the mods you listed, I think you'd be around 13.8's since you don't mention a blower upgrade only porting. That would probably be similar to an S-port.
 
I'm running 12.8 to 13.2 right now. Check out my mod list on my memberpage. A double or FMIC would be help. Try to make your run on a bright sunny crisp chilly morning. I seem to run my best times then. Good Luck.
 
You can go 12.9's with as little as 104 mph if you are hooking up good. That doesn't mean you have to go 1.6's short times and yanking the front wheels....but you have to be hooked good. Stan Wodzisz is a good example of how to get into the 12's with as little as possible. No nitrous, no major weight reduction and stock valves.

http://www.sccoa.com/member/index.php?uniquename=wodzisz

Oh and FWIW, he estimated his car to put just under 300 HP to the wheels.

Micah
 
12.9 is my goal with a stock motor.Don't think I am going to make it though.
Going with some lower gears in the rearend.This may get me a little
closer to breaking into the 12s.

Good Luck RANDY
 
Wow stan's car would only make you think high 13's. It runs damn good with the smaller MAF and TB. The gears and convertor must really help with slicks to get these tanks off the line.
 
That gives me a lot of hope because I am not scared to yank out my interior for the track.

Think I could touch into the 12's on a $2000.00 budget?
 
Why wouldn't you want a locking converter? I know it isn't an option, but still I haven't been told the reason why you wouldn't want one.
 
because its pointless to put a 5000 rpm convertor in an SC :rolleyes:

The weight of these cars is easier moved by allowing torque multiplication in 3rd. Drive an AOD they are dogs when the convertor locks. They pull good in 1st and 2nd. Take to long to rev (gears in the rear) but thats another story.
 
My hope was to do gears and converter to do most of the work....then port my existing stuff then add other mods to achieve my goal.

-Darrel
 
A lot of people think running off of low end torque is the way to do it, but that's not true in the least nor is it ever when talking about 1/4 mile ET. I have, from experience, found that weight has very little to no effect on converters. ONLY GEARING. Torque converter's transfer power to the rear end and then the rear end gears control how it gets to the tires. I've already explained a couple of times what happens. Go ahead and worry about 3rd gear multiplication whenever all the ET comes from the first 1/8 mile of the track.

A converter being locked up and being flashed to the set stall is two different things. Just because the converter is locked up doesn't mean it doesn't flash to whatever RPM, since you said 5,000 then we'll use that as the example.

Here's what happens in a daily driving situation. You put the car in drive; even though you have a 5K stall converter you are driving around at 1500-2500 normal driving with no problems like you have a bone stock converter in there. You then decide to have some fun. You mash the pedal and the tach jumps to 5K, you rev it to 6K, then shift, and it doesn't drop below 5K and repeat what I just said until you're done.

No a 5,000 converter isn't pointless in an SC. If you feel you want less stall for some reason then get a 4,000-4500 or so stall. It depends on the desire of ET you want to run. He wants a 12 second SC so that means he will have to have head work and a cam which can be operable for 6,000RPM through the traps. More than plenty of RPM throught the traps to run a 5K stall. Hell, Burbank's SC has no head work or any aftermarket valvetrain and he revs to 6K running 13.50's with alot less mods than 90% of the SC's out there. Yes he is a 5spd car, but I was using him as a trap RPM example only.

I could bet my life on Neibert's car running 11.0's or better without nitrous on a 5K stall 8" lock up converter. If he went to an aluminum drum, lightened tranny with a tranny-brake he would run 10.80's. I know you won't believe it, but I've seen some crazy ET picked up by switching to that setup from a stock type.

I listen to many hipo street car guys with auto's tell me this same thing about running their cars off of peak torque, while being mad about their own cars not falling out of a tree. They won't listen to me or anybody else who understands the right concept because they dont understand.
 
CMac89 said:
Why wouldn't you want a locking converter? I know it isn't an option, but still I haven't been told the reason why you wouldn't want one.

I think what will actually work best is 4.10 gears and high stall at least 3500 and as soon as the transmission shifts into second lock the convertor up with the computor. You are absolutely correct CMac you don't want to run the whole 1/4 mile with the convertor slipping as it is a waste of horsepower. As for running 12.90's with those mods I think it can be done and if I can get my car healthy enough to go to the track I plan to do just that.

Charles
 
"A lot of people think running off of low end torque is the way to do it, but that's not true in the least nor is it ever when talking about 1/4 mile ET."

Actually, that's opposite of what Stan's philosophy was. He always contended that these cars were so good at putting down torque, that you should focus on this and make it to your advantage. He had a low HP, but torquey combo.

And while it was possible, Stan is the exception here. He could show up at the track with that combo and run a 13.3 or 13.4 with little effort, but it took some work and learning how to launch to get 13.1's. I don't know what he did to pull 12's, but I know it wasn't much.

Micah
 
Johnny Langton runs 12's with under 300rwhp. Think about that for a moment.

{edit} And as mentioned above, a high stall locking converter is the key to doing it.
 
Can you get enough rpms to run the mph needed for a 12.99 with 4.10s??6000rpm would be 101.5mph 6250 rpm would be about 106 mph. What all would be needed to spin the engine to 6250 safely?

-Darrel
 
To actually spin the motor at that RPM "safely" you would need to have some good aftermarket valve springs (type debatable), and some chromoly pushrods. I would suggest getting some roller rockers too. They don't free much power, but I wouldn't think they would last long at 6200RPM.

Don't get me wrong, i'm not saying that nobody knows the concept, I just want to mention it whenever necessary to get the word around. Doing this might get people thinking of a great combination to put together.

Remember guys, the motor is only half the story.
 
My car ran 13.50@102.51 with 4.10's using stock heads, cam, valve springs, stock transmission and convertor, shifting at 5600 and turning the engine around 5800 through the traps.

Charles
 
remember that with the 4r70w you don't need as much gear as an AOD.

Hmmm... if I spring for a 4500 RPM convertor for my SC and run it with 4.10 gears, I better see a difference because of giving up my low end torque. I'd be tempted to try it just to see if it works on an SC. Wouldn't that risk breaking something though? Launching that high? What about the foot brake, could it hold back a 4500 rpm convertor to the flash point or would I need a trans brake?

Who makes a convertor like that and do you think the split pattern shaft in my trans would be able to survive or would I snap it on the 1st pass?

I'm all about anything to get this tank off the line quicker and if it locks up for street use thats better for me. 5000 stall seems a bit much. I am not sure where my HP peak is, probably 4500-4800 rpm. Wouldn't I want to stall into it rather than just over peak?
 
Last edited:
Scott Long said:
remember that with the 4r70w you don't need as much gear as an AOD.

Hmmm... if I spring for a 4500 RPM convertor for my SC and run it with 4.10 gears, I better see a difference because of giving up my low end torque. I'd be tempted to try it just to see if it works on an SC. Wouldn't that risk breaking something though? Launching that high? What about the foot brake, could it hold back a 4500 rpm convertor to the flash point or would I need a trans brake?

Actually you do need that much gear with the 4R70W, the car is still a heavy pig and needs all the help to get moving it can get. If you notice my car is a 95 and has a 4R70W and runs mid 13's consistently but still has fairly slow
60' times because it needs a convertor to go with the gear otherwise I feel certain I would already be running 12.90's.

Charles
 
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