Would my prom unit be causing my computerized 700-R4 to not shift when I want it to?

Ok I have a 700-R4 highly modded with a pretty heavily modded engine on a stock prom unit. When I race I put my slapshifter in first, but it shifts to second reguardless of whether I move it or not. This doesnt bother me that badly but It doesnt want to shift from 2nd to 3rd if I have my foot on the floor it just runs the tach all the way out even if I put the shifter all the way in overdrive. I have to take my foot almost halfway off to get it to shift to 3rd.


Would this be caused by the prom chip does it tell the tranny when to shift? PRIOR to all my new upgrades like getting a 3 angle valve job headers flowmaster big cam I raced a GT stang that ran a 14.5 I absolutely tore this guy up through the 1/8 I mean like 2 and 1/2 car lengths and pulling away until the car ran out in 2nd and wouldnt shift there was nothing I could do save cruise to a 15.6 and be mad as hell.

Id apreciate any suggestions I mean If I was pretty fast then with all my new stuff I should haul major ass now. That is if the tranny shifts like it should I thought Id ask for suggestions before I took and ran it on the new motor.

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I find your lack of faith disturbing

86 IROC .040 305 TPI
#186 Heads shaved .040 1.98 valves
Shorty Headers 3 in exhaust with Flowmaster
Lunati 259/271 .500/.515 cam
Highly Modified 700-R4
B&M Slapshifter
3.55 Posi Rear
Accel Plugs and Wires
Petronix Flamethrower Distributor
Cragar 15x7 front 15x10 rear

700R4 is all hydraulic, nothing to do with the PROM

Yeah a 700R4 is not computer controlled at all. You have somthing wrong with your tranny.

First do you have an aftermarket kick down cable? Second Did you recently put the shifter and cable on or has it been on there for a while and just start doing it?

I believe the the prom only controls the lockup if anything at all. Nothing to do with what you are describing

Um..... actually the 700-r4 is brand new.... like 4 times. Damn weak ass trannys I would rather just go with a TH400 but then I wouldnt have overdrive. I payed the guy to rebuild it after it first time it went out a few times after that and he did it for free becasue it waswihtin a year. It runs really well just driving he put tight ass springs in it so it shifts like a dream.. thats is to say when it shifts http://web.camaross.com/bb/smile.gif. Someone said something about an aftermarket kickdown cable or something, wanna expand on that plz.

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I find your lack of faith disturbing

86 IROC .040 305 TPI
#186 Heads shaved .040 1.98 valves
Shorty Headers 3 in exhaust with Flowmaster
Lunati 259/271 .500/.515 cam
Highly Modified 700-R4
B&M Slapshifter
3.55 Posi Rear
Accel Plugs and Wires
Petronix Flamethrower Distributor
Cragar 15x7 front 15x10 rear

First of all, the 700R4 is not a weak tranny. Not everyone knows how to build a 700 correctly, thats why they continue to break.

The biggest problem is that everyone wants them to "chirp the tires" even when its not at WOT. All this is doing is putting stress on the trans when its not necessary and making it fail sooner.

The other thing is that you have to have the TV cable functioning properly and correctly adjusted. It sounds to me like your problem is the governor in your trans isn't matched to the rear gear ratio, therefore it trys to hold the gears longer. The governors tend to fail on these trans' too so you might want to get it checked out either way just in case.

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Mike L.

1987 IROC Z 5.7 TPI A4 3.27 Borg-Warner four wheel disc
Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified airbox w/ K&N's, Relocated MAT sensor, Gutted MAF, 160* thermostat, MSD 6A, Accel 8mm Wires, bypassed TB coolant, 3" Flowmaster 3 chamber single outlet, custom adjustable cutout, 3" MAC mandrel intermediate, airfoil, ported plenum. !smog, Crane AFPR, Accel rail mounted FP gauge, Harlan shiftlite, 24lb. injectors, Hedman headers, a few others I forgot...??? FINALLY GOT PAINT!!

Check out my IROC webpage! (http://iroc5.7tpi.home.att.net/wsb/html/view.cgi-home.html-.html)

<font face="Verdana, Arial" size="2">Originally posted by IROC5.7TPI:
First of all, the 700R4 is not a weak tranny. Not everyone knows how to build a 700 correctly, thats why they continue to break.

The biggest problem is that everyone wants them to "chirp the tires" even when its not at WOT. All this is doing is putting stress on the trans when its not necessary and making it fail sooner.</font>

I had Lingenfelter redo several things and burn an ERPOM for me after I stuck in his 450 HP 383. This was a couple of months after GM had rebuilt my tranny under warranty. Before I left his faciluty, he asked if I had the stock tranny with a shift kit. I said yes. He told me that I would get home but the tranny will only live for no more than a year. I babied the car because I was new to that level of power and it was winter. I had to take a month out of June to take care of business overseas. 6 months after I left LPE, the tranny died. Called him up and he recommeded www.rosslertrans.com (http://www.rosslertrans.com) to rebuild the tranny. Cost me around $1600 with a 500rpm above stock stall converter. It lasted me for 3.5 years with me beating on it. I make at least 2 WOT runs a day.

Told Rossler to set it up the way he does it for LPE. He asked if I wanted it to shift hard at WOT and soft at normal driving or hard always. They felt that there would be less wear on the clutch packs if it shifted hard all the time. I had it shift hard all the time.

Right, mine doesnt shift so hard that it chirps the tires; its just a nice hard crisp shift. And granted it was my fault that it went out so many times in so little a period (its a long story Ill just say I forgot to tighten down torque converter bolts and broke my flexplate which knocked out my front pump..... about 3 times) The last time it wsa rebuilt the shifting periods were way off so I took it to the guy who built it and he adjusted the kick down cable and fixed the shift times. I wonder if I played with that if I could make it shift to 3rd earlier.

Also Ive had people tell me that It shouldnt shift to 2nd if the shifer is in the first position (which it does) and to 3rd in 2nd position. Is a 700-R4 supposed to shift like this if I dont move the shifter myself.

Just out of curosity if its not computer controlled then whats that electronic plug that plugs in just above the pan on the driver side?

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I find your lack of faith disturbing

86 IROC .040 305 TPI
#186 Heads shaved .040 1.98 valves
Shorty Headers 3 in exhaust with Flowmaster
Lunati 259/271 .500/.515 cam
Highly Modified 700-R4
B&M Slapshifter
3.55 Posi Rear
Accel Plugs and Wires
Petronix Flamethrower Distributor
Cragar 15x7 front 15x10 rear

<font face="Verdana, Arial" size="2">Originally posted by DarthIROC:
Right, mine doesnt shift so hard that it chirps the tires; its just a nice hard crisp shift.

Just out of curosity if its not computer controlled then whats that electronic plug that plugs in just above the pan on the driver side?</font>

Mine does chirp the tires going into second.

AFAIK, the plug controls the lockup for the Torque converter when it is in Overdrive

Mike is right the gov is bad. If you leave it in drive and step on it the trans will shift too early or late if the gov is bad. The TV cable will have a slight difference unless it is broke or worn out. Then it would be greater. The ECM has nothing to do with it. As was said it only works the lock up of the converter. Make sure the TV cables ok then if that is not it then you know for sure it is the gov.

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87 IROC L98 700R4 A few mods. Best et 12.96 at 110 mph
All motor No NOS or Supercharger.
96 WS6 FORMULA Best et 13.5 at 105 mph