Anyone, anyone???  My tranny is wasted and I am really anxious to have it repaired/replaced/upgraded.  Jeff's kit is unavailable, and nobody knows/wants to build a 4T60 for high performance that I can find.  My best option right now is a fresh stock Grand Prix rebuild from a local TGP friend.  Anything would be an improvement over my slipping, grinding unit I have now but I am slightly apprehensive about spending the $$ for a R&R (FWD tranny removal is over my head) if a stock unit may not last long behind my 12 PSI TopGun stock motor which will be recieving a turbo upgrade this spring and much higher boost levels.

I'm looking for something to hold in the 400-450 LB-FT torque range.  Is there even such a thing made?  I drive this car every day and I'd be lying to you all if I didn't admit I generally go WOT thru 2nd gear at least twice a day.  (I let off right at the shift.)   I am willing to pay to have it done right but I don't want to go overboard, keep in mind this car is only worth $3000 tops.

If there is no such thing as a transmission that will last I guess I'll have to look into buying a different vehicle and abandoning the Turbo Grand Prix project..   I don't have the time or $$$ to do FWD transmission Research & Development.

Josh

Quote from: TookyCatif a stock unit may not last long behind my 12 PSI TopGun stock motor which will be recieving a turbo upgrade this spring and much higher boost levels. Josh

Just to help keep other TGP and TSTE owners from freaking from this, who are chip'd or doing their own chip and/or upgrades, the TGP Tranny used/60-160k+ miles can last quite a long time, for sure long as owners don't do sustained high speed runs.  I had a TGP owner who ran a corrected 13.56 and logged over 300 quarter mile runs in HOT Arizona weather, and never had the tranny fail.  There have been some failed trannies, most from high speed runs, but any 14 to 15 year old car is going to need repairs and the TGP tranny is no different.  Your tranny failing, no way for sure to know how it was used or cared for in the past before you got it right?  Did you check with Level 10 as I suggested?  I know someone with a TGP had a 3,400 unit that was supposed to handle 400+ hp (torque?), and was done by Level 10.  Maybe manual is the way to go if you don't like or can't trust the tranny at 400+ hp levels, that is asking a lot, but if you want to run that much hp and be that fast, might have to find a GTP to get you there 8) .

Jeff M

Good luck, I've been chasing this goat for over a year(and 10 trannies!!!!!)

Well guys, this has been a major sticking point for me and has really taken the wind out of my "TGP Performance" sails, so to speak..   I don't care for manual transmissions especially on a turbo vehicle so that's out of the question.  I did contact Level Ten and here is what they responded with:

QuoteDear Josh,
   We do offer a pts transmission system 4t60 that is capable of 600 hp and
675 lb ft torque. It will also get rid of all the lag and the hesitation off
the start and shave off anywhere from 1/2-1 second off 1/4 mile times.
Shifts faster and delivers up to 11% more power to the wheels.
pts transmission system $2464.
pts torque converter upgrade $498.
Your core is required.

On the bright side, it sounds great that someone DOES offer a good tranny.  On the down side, I would prefer to see someone else vouch for this tranny's ability to last and drive properly before I consider dropping the big coin on it.  Also, $2500 WITH my core is definitely not cheap!!  Plus the converter being extra.  Damn at $3000 I've already exceeded the value of the car.  I'd be willing to spend a fair amount to get a proper TGP tranny but this far exceeds even the cost of my "10 second capable transmission build" for my Syclone.

As far as GTPs go, I'd rather sell the TGP before I get a GTP..  way too common for my tastes.

Maximage, could you share a little of your tale(s) of woe?  I would be interested in hearing the problems you've had so hopefully we can benefit and avoid the same mistakes...

Finally to clarify, I was not referring to putting in a stock TGP transmission, but rather a stock W-Body transmission that has been rebuilt with a shift kit.

Thanks,

Josh-

Performance + FWD + Transmission = Not Cheap.

There have been guys who can get basic rebuilds with R&R done for less than $1500. But not much upgrading done there. Probably a clutch kit and MAYBE a stovepipe. Certainly need much more to upgrade. Hardening of input shaft, cogs, new HD chain, OD clutch upgrade, upgrade stovepipe, new upgraded accumulator springs etc. These are just things I picked up on hanging around a guy I know with a trans shop who does work on alot of "taxi" transmissions. I would also look into any parts available for 4t's behind the caddie v8 engines. Maybe some better stuff there.

As far a level 10, I haven't heard about them lately. But arron Lephardt (??) had quite a bit of problems with their trans upgrade in his SC GTP Conversion GP. I also noticed they said PTS which is a company in california that does a lot of GN trannies. Maybe they are just sending them out/using their parts?

Just my limited input.

Chris

What do you guys do to your trannies? Geez... 180,000+ on my TGP with the original tranny. Just barely had a little slip between the 3rd to 2nd downshift. It had been neglected very bad when I got it. The fluid was almost black and the filter had goey fluid in it.

I think one factor is the torque produced by the Turbo V6 motor once you "uncap" the torque limitations of the stock boost control.  GM rated the stock torque at "225@2100".  What a joke, there is no way this motor makes peak torque at 2100 RPM.  The LH0 N/A 3.1 V6 was rated at 180@3600 and both motors have the same cam.  So they lied because the true torque number is higher and did not want to advertise that.  McLaren set up the boost control to severely restrict boost below a certain RPM (~4000?) because it is a fact that high boost at low RPM = huge torque output.  That's normally a great thing unless you have a woefully inadequate transmission and it appears they did; so their band-aid fix was to limit the engines low end output instead of building the transmission.

Now if you take a TopGun chip it still limits the torque but not as much as a stock chip.  However if you put a manual boost controller on, it will allow as much low end torque as the engine is capable of producing, and I think this is what really pours the tranny to the coals..  I know it did for mine (my transmission wasn't 100% when I bought the car but it definitely took a turn for the worst when I tried subjecting it to 300 LB-FT+...)

Quote from: TookyCatHowever if you put a manual boost controller on, it will allow as much low end torque as the engine is capable of producing, and I think this is what really pours the tranny to the coals..  I know it did for mine (my transmission wasn't 100% when I bought the car but it definitely took a turn for the worst when I tried subjecting it to 300 LB-FT+...)

just curious - what are you using for a manual boost controller?
joshua

Quote from: malibuolds

Quote from: TookyCatHowever if you put a manual boost controller on, it will allow as much low end torque as the engine is capable of producing, and I think this is what really pours the tranny to the coals..  I know it did for mine (my transmission wasn't 100% when I bought the car but it definitely took a turn for the worst when I tried subjecting it to 300 LB-FT+...)

just curious - what are you using for a manual boost controller?
joshua

You've got me wondering now too

I'm using the www.boostvalve.com "universal" controller I bought about a year ago for my Syclone.  In winter I transfer it to the TGP.  It is surely the mod that's made the biggest difference in my TGP.  It spools so much faster and feels so much more powerful.  In fact, this is a true story, I let my Dad drive the car (he's driven it before) after I put on the boostvalve but I didn't tell him; when he returned he said "What did you do to that car??!  I never drove something that was so responsive"

There's nothing magic about the Boostvalve; it's just a ball and spring "grainger valve" that does not leak signal (like a bleeder would) and it does not send ANY signal to the wastegate until the limit is reached.

Great fun, and guaranteed to put a smile on your face; but just keep in mind that making this much power may make the tranny cry uncle.

I made one of those grainger valves for my friends SR20DET powered sentra.  The ball and spring setup works very well and it does help decrease lag a bit.  You can get the valve from grainger for around $9, and add a couple barb adapters and you got a boost controller for under $20.

So, after one installs the Boostvalve or similar manual boost controller, what do you do with the stock boost controller? Remove it, or keep it? What does the ECM do if you remove the controller?

The stock boost controller can sit there and remain plugged into its WeatherPak harness.  The computer doesn't care either way.  Its nice to keep it in case you have boost controller issues and you can hook it right back up.

If you install a manual controller take it EXTREMELY cautious with the boost!!!  You can easily kill your motor with this, I would recommend setting no more than 11 PSI, and leaving it there.  Substantially more than that will not only be slower, but it will cause catastrophic engine failure.

Sorry it took so long to post. Been working on my house all weekend. My biggest problems for the first 3 trannies were more or less a poor choice in tranny shops. They didnt realize that the TGP trans was different, and wouldnt listen to me when i told them so. The rest of them have fell victim to my experimentation. We decided with tranny 4-6 that someone else would do them, and had a very reputable shop go for it. The first was a stock rebuild, which got taken out by a clogged cooler(forgot the cooler, wont do that again!), second stock rebuild fell victim to massacred clutches. To much power for the stock trans(my car at this point is far from stock, but since I do my own custom parts and tuning, it's staying under wraps untill done). The third is when we started letting our trans guy do some experimentation. It worked great for about a month. The rest we have done at our shop(because by this point we've seen and had our hands on this thing apart a lot!). We had a different guy we know who does custom trans work go through it with us. Unfortunately the biggest probs we've had since then are high speed runs. We cant seem to keep the overdrive gear from locking in at 120+mph runs. Otherwise, we have it down. I'll see if I can get him to do a run down of the parts we have in it now. Just don't slap into overdrive above 80mph!

just as a thought, not sure if it would work, but what if you took a tranny out of a GTP and put a better shift kit and converter in it?