Getting the Slip

[231power]

Could use some help from the tranny experts. My 2 - 3 shift got bad over the course of prob the last 1500 miles last summer to the point where it feels like it`s slipping into neutral. It would occur while city driving and medium acceleration. Tranny is all stock as far as I know. Any idea what I may be looking at for a repair in the spring?
Should I be looking for a converter upgrade since it`s going to be on the bench anyway? As far as goals, the car is at around 290 horse on the dyno and it`s a cruiser that I`m starting to take to the track. I`d like to see times into the 12`s with it at some point but she`s not there yet. Thanks for any info!

 

[231power]

Any thoughts anyone on a converter upgrade? thanks

 

[turbo nasty]

the 2-3 flare/slide shift is where teh trans usually dies at. Very common.

I prefer Lonnie at Extreme automatics. But Janis, Hofer, Century, otto are some very good builders as well cant go wrong with those.

The local builder that can install all teh goodies from Trans go, ato isnt gonna get it its best to get a trans from one of teh above many have them with no core.
Get the Billet forward drum as un upgrade.

Your goal of the 12's can be done no problem with the stock Convertor.

If you are going to another turbo then it may require a higher stall but for your ET goal IIMO its not needed.

Get the trans straight slap on some good sticky tires leave on the convertor and you should be in the high 12's all day with whats in your sig

 

[231power]

The local builder that can install all teh goodies from Trans go, ato isnt gonna get it its best to get a trans from one of teh above many have them with no core.

I can't quite tell what you were saying in this line at 'isn't gonna get it'.

Btw, the best I got at the track was a 13.7, but on street tires and I've done very few runs. Definitely room for improvement.

Thanks a lot for the info.

 

[turbo nasty]

Sorry dude im the worst typist on earth.

I was saying that the local guy that can build TH350's and 400's that "says" he can put all the good stuff from B&M, TCI, Trans Go, ALTO in teh 200 and it will work isnt a good choice.

Best to send it or buy one from the vendors on the site

 

[gusszgs]

The combo in your sig should put you in the 12's. I run 13.7 bone stock and no alky. Just a K&N, adj wastegate, and MTDR's.

 

[bentwings]

This is my first post here so bear with me. I am a long time racer and hotrodder so long on tooth as they say. I actually did the new car prep on the first 2 turbo Buicks in the Twin Cities way back when. Naturally they 'failed' and required 'additional' service. haha So I got to 'road test' them as only a hotrodder can.

Anyway regarding the 'slip'. I have a 350 SBC with a 6-71 blower and 400+ rwhp with a T-350. I ran into the vac mod problem head on last fall when we started driving it. No amount of adjusting cured the 'slips' which really showed up on the 2-3 shift. It's hard to really test on the street as the car stands out with the blower and is really fast and noisy. It can attract unwanted attention. ie black and whites.

The 2-3 shift started slipping when there was boost but not when there is vacuum. Shifting was irratic where is was nice with just the Holley carb. Sitting down and thinking about it shows that there is vac and boost possible in the modulator line. The mod is really only designed for vac (unless there is a special one for the turbo 350 Buick). with pressure the mod causes max shift pressure however the trans shop guys tells me that with 5-6 psi pressure you can not only destroy the mod, it's possible to over ride the governor valve. Now I'm new at the trans internals but I do have the book and I'm studying it. I don't know if this is fact however.

Anyway searching brought me here since the T-350 is used with your turbos. Turns out that Transgo has a device that goes in the mod line that relieves the boost pressure from the mod so the mod works as designed. I just got the thing this week and haven't had the chance to test it yet. Maybe this will help you.

Here is the P/N. The guy at Transgo says it works great.
VBP-VAC

 

[overkillphil]

Unless I missed it, the OP is running the original 200-4R (which does not use a vacuum modulator or vacuum line).