Trap Gear? trying to figure out if stall is too much

[turbo96max]

Guys,

I just started taking the car to the track and I am worried about hurting something by not shifting into 4th. I have been told that I should be good running throught the traps in 3rd, but I would like to be sure.

The car has a 3200-3500 stall nl converter, the first time out ran a 12.7 3 times @ 107 and i didnt put it into 4th.I didnt shift it either, just put it in 3 gear D and left.

are many guys shifting into 4th? is 3rd a general rule of thumb? It didnt hit the limiter , but im hoping to put a meth kit on it soon and turn up the boost so i want to be sure im not going to hit the limiter since we have fuel cut not ignition cut. actually, what rpw does the limiter kickin on a stock ecm?

 

[Jerryl]

Guys,

I just started taking the car to the track and I am worried about hurting something by not shifting into 4th. I have been told that I should be good running throught the traps in 3rd, but I would like to be sure.

The car has a 3200-3500 stall nl converter, the first time out ran a 12.7 3 times @ 107 and i didnt put it into 4th.I didnt shift it either, just put it in 3 gear D and left.

are many guys shifting into 4th? is 3rd a general rule of thumb? It didnt hit the limiter , but im hoping to put a meth kit on it soon and turn up the boost so i want to be sure im not going to hit the limiter since we have fuel cut not ignition cut. actually, what rpw does the limiter kickin on a stock ecm?

Usually, just run in 3rd through through the traps.

I would personally NOT cut the fuel.
If you cut fuel under boost you will go lean and blow something.

What RPM does the car shift at?
If the RPM is too high through the traps, calc the converter slip and get a taller tire.

You will need to post your complete set-up so the experts can advise on RPM.

 

[pacecarta]

stock chips fuel cut limiters may be as low as 5750 and the most a chip maker can set it to is 6250 ,
if you're spraying meth get the limiter removed from the chip!!

most dont use 4th but i did with my 86 when running 26" tires trapping 128 you really need to be sure your tune is good before dropping into OD as most will go right to knock from the added load of the gear

and you really cant judge your trap vs rpm based on a lower speed
usually converters gain efficiency as the rpm rise up to the point where they blow through from too much HP

, logging your runs on directscan or powerlogger you can better see where the converter coupling point at your hp level is by looking at the shift drop to point on your 1-2 and 2-3 , below that rpm the converter is usually very inefficient and slip will decrease above that , so lets say you're at 107 at 5200 you could have 20% slip or more if its coupling point is 5400 but at 6000 you may find you only have 8 % slip and at 6300 maybe 5% with the same converter which is typical of the art carr 9"
i didnt feel comfortable spinning a stock bottom end at 6000 and if you're on stock cam theres really no point pushing it past 5400 so you want to size your tires and pick your converter efficency for that


we been told the MPH and et but what tires are you running? are you still running the 3.42 rear gears or did someone put 3.73s in there ? whats the rpm at traps ? where is the trans shifting at and dropping to on shifts ?
ive run stock bottom end on 26" tires to 120 in D with a converter that is considered very inefficient compared to the new ptc converters
on a 28" i can stay in third to just over 129 @ 6000 -6100 (need a cam for this rpm)

, post up as much as you can about your combo , better yet go to user cp and put it in your signature

 

[Scott89TTA]

What's up Alvaro...just realized it was you

when you post all the info Paul spoke of here are some good calculators to figure it out...been going through the exact same stuff with my car as we speak

TCI - TECHNICAL INFORMATION: Racing Calculators

I'm hoping to try out a little more boost and lock my converter this weekend and see if I can get booted from Cedil


-Scott

 

[turbo96max]

thanks guys, it looks like i will need to do the powerlogger for sure as i dont have all this info. i lack the rpm data for the shiftpoint or the rpms at the traps for that matter. I dont have a tach yet and i just ordered my wideband.

here a little more info it it helps, but it sounds like i should be ok for running in 3rd.

tt race chip with timing and fuel backed off to use 93 oct
275/60/15 street tires
wests coasts nl 3500 verter
pt 63
lunatti 210/208 cam
bigger valved p/p irons

Im hoping to do the meth kit soon, so thats why im wondering if im ok before bumping up the boost. dont want to hit the limiter at high boost..seen it b4, not good, holes in block

the most important info which is the rpms i dont have so thanks much , and i think i may have to do the powerlogger rather than the meth