I thought this thread would be good for the community... I got my torque converter (TC) rebuilt by ProTorque out of Long Island, NY. Before I settled on ProTorque, I went online to find out who was regarded as the leaders in the TC business. I didn't have to go onto too many boards, before I ran across ProTorque. They have an excellent reputation that seems to be second-to-none.

From what I understand, they have been building TCs for over 30 years and that is all they do. They handle multiple racing sanctions including "pro street" and "pro mod" with some applications exceeding 2500 hp (not a typeo)!

As I joked with the guys there, I am only making "prius-level" power to these guys.

Here is an article written about them last year:

http://www.dragzine.com/features/sho...he-revolution/

Edit: Here is a more current article vindicating their status among high HP cars

http://www.dragzine.com/news/protorq...ters-drag-week

They were a pleasure to do business with! Very responsive and knowledgeable.

From what I have seen online, the Jeep SRT8 guys are shaving at least 0.3 secs off their 60 ft times. Some of these guys are cutting a staggering 1.6 sec 60 ft (short gearing, low end torque, high stall TC, AWD)! If I can get close to this, I expect to shave close to a second off my quarter mile times.

Here is the pic of the new TC:





Putting it into this new arrival:





Should have it installed by this time next week, so I will let the community know how it performs!

 

Reserved for review

For those interested, here is a good 3D video explaining how a TC works:

 

Subscribed

 

Did you embark on this project "just because", or was there a preceeding event that made it necessary? I know SeattleTurbo will be interested in this, he mentioned looking into a higher stall converter too.

 

Im at work so I couldn't quite squeal with excitement when I saw this thread title, but Im thrilled




Kent, are you able to discuss how much this cost, the specs (stall speed, etc)? Eagerly awaiting your results!!

 

I knew you had mentioned looking into it.

By the way...I have Kent's old intake and throttle body in hand. Time to start seeing about how to make It work.

 

The latter... had tranny issues one night while brake boosting to 3K. Started to rev in place and had extreme slippage. All signs were pointing to TC, so I dropped the tranny and sent my TC out for a repair and high stall rebuild.

Apparently, they didn't see anything wrong with the TC core I sent in, so I had an important decision to make. Either take a chance that it was the valve body causing the TC-like symptoms, spend about $1K on a replacement and another 18 hours to put everything back together and cross my fingers that I didn't have to throw another 18 hours to pull everything back apart, or just buy another tranny from Porsche with a new valve body installed and know that the issue will be addressed the first time. I chose the latter.

Unfortunately, there is no used market for 957 CTT transmissions; meaning zero in the US that I could find for sale.

Glad to see we can create some excitement in this subforum!


Since pricing can fluctuate, send me a PM and I will let you know what I paid. It was cheaper than a new OEM TC. Since this was a rebuild, not a billet TC made from scratch, they can only modify the stock TC design. The way it was explained to me, think of it like "porting" a head. They make it better, but only by a certain degree without throwing it away and starting a fresh design.

Ideally, I wanted a stall speed that would put me into my boost curve. I requested around 3200 rpms, however, they made no exact promises about where this would end up. I looked into it and apparently there are a lot of factors into determining flash stall speed and brake stall speed.

All in all, it depends on how much torque you are making down low. If you add more power, it will increase your stall speed with the exact same TC. Not intuitive; I know.

 

These guys seem to have a lot of used trans but I didn't see one for a 957 CTT. Not sure if he sells many but he seems to have a lot in stock if the pictures are accurate. http://stores.ebay.com/LKQonline/_i....=&_ipg=&_sop=1
You couldn't get it rebuilt? I know I talked to a local guy here when deciding what to do about my valve body and he mentioned he didn't do much work on this model.

 

You are right. LKQ is a huge automotive recycler that I have used in the past. However, no 957 CTT transmissions. The CTT has upgraded internal friction discs to deal with the added tq, so I would not want to used a GTS tranny for example.

In theory, yes, but there are several issues. ..like..

• It may not have needed a full rebuild if the valvebody was the issue
• Aisin (the OEM supplier) does not provide "hard" parts for this transmission, so if anything out of the basic seal/friction disk broke, they wouldn't help
• Aisin also does not talk to end users, only car manufacturers and recommend you take it into your dealer
• Not sure if I would trust a local guy to rebuild it correctly
• It would still costs approx a couple of grand to do this and there is no guarentee they can complete it if they cannot get the parts from Aisin

All in all, it wasn't worth the risk and hassle. At least this way, I have new tranny with 0 miles on it - pretty much guaranteed to work.

 

Yep!! I feel like this is going to make all of the difference in the 1/4 mile times for the CTT platform.


Ahh Ive got some ideas, if you have any pics of the manifold, specifically the underside and where it would connect to the head.. I think we may be able to figure something out. I was studying my intake pretty closely this past weekend trying to brainstorm.




I'll get a message to you shortly, thanks! Definitely excited to see how it works for you, the effect on drivability, and how it performs!

 

@ Rm, couple of quick questions. When you ordered your torque converter did you guys talk about ballooning or any way to strengthen that torque converter since it is a lockup design did you guys talk about adding more clutch plates or different friction material? Do you remember if they were able to build a custom billet torque converter?

@11 and three quarters inches that torque converters kind of big, did you guys talk about any options on the building a smaller maybe like a nine and a half or an 8? did those guys give you any idea of what they think I modified Stock converter might be good for power wise?

 

I know what ballooning is on a TC, but didn't think I was at the power level where this was a serious concern. Neither one of us brought it up. Probably b/c it would have been the billet TC conversation that reaches a dead end. More on this below...

This was a multi-clutch TC (not sure how many exactly), but did have them change out the friction material to another highend aftermarket provider. Not sure who was the actual supplier, but know they had a hard time sourcing it and it was costly.

Yes, they can and do for other applications. But for something this low volume, it would take months and exponentially more money. This isn't there number, but another TC rebuilder place quote me on the magnitude of $10K+ for a custom stall, billet option.

Yes, it is a big TC. I know he said that a lot of the high HP guys run a smaller 8" TC. However, those guys do not have lockup clutches; we do. From what I understand online, for lockup clutches, you want a larger TC since it provides more surface area to clamp on. When mine was opened, they said they saw some moderate heat wear on the clutches, but nothing that would have caused any issues. This was enough for me to deter from downsizing (not that I think it was an option).

Also, I am not sure how the stock TCU deals with lockup. From other tiptronics, it seems like it might lock up at certain rpms ranges for added performance or fuel economy.

No, but good question. I would call them and talk to Mike Brown (good guy). Let me know what they say.

 

Update:

Okay new transmission with ProTorque TC has been installed over last weekend. Going..going..gone.

 

Results

So I have put about 400 miles or so on it so far and all is good. The high stall TC is definitely noticeable. Leisurely, the truck does not start to move until about 1800 - 2000 RPMS; stock stall I believe was about 800 RPMS from the documentation I have seen. With the high stall TC, from a dead stop and going WOT (no brake boosting), the RPMS will kick up to 2900 - 3000 RPMS before launching really aggressively (more on this later).. with a preceding 6-10 feet of slow creep, before taking off.

I tried to get some VBox 60' times and 0-60 ft times, but this 6-10 ft rollout is killing my times. According to VBox, during the creep phase, it doesn't get up past 1.5 mph for just under 2 seconds, before the TC reaches its flash and launches the truck. I have talked to a few people, including ProTorque, and I am pretty sure I need to just figure out the right "launching technique"and all will be well here.

Moving on, the truck launches really aggressively, but not violently. Which is a little puzzling, since according to my last dyno, it should be putting out about 460 ft lbs of tq at 3000 RPMS to the ground. I thought that that much power to the ground all at once should equate to a violent launch and much lower 60' times.

To that end, I started to watch the factory boost gauge while the TC is getting up to its 3000 RPM flash and noticed that the gauge was not moving at all Once the flash is reached at 3000 RPMS, and the vehicles starts to launch, then you see the factory boost gauge start at 0 bar, then start to move quickly up. So what I can see so far, it may not be building boost off the line, like it should...stock turbos start spooling at 2,250 RPMS

So in this scenario, either:

A) It is actually building boost and the factory boost gauge is inaccurate and doing whatever it wants to do. And the launch isn't really violent due to the wide 305 tires on all four corners, AWD, tall 3.23 gearing, about nearly 6,000 lbs weight.

or

B) The DME is replicating what it is doing when you rev the truck in park and neutral. When you rev the truck in park/neutral, even though the RPMS go up and you hear the turbos spool, if you look at your boost gauge, it wont move off "0 bar". So the DME may be either electronically opening the internal turbo wastegates to vent boost pressure and/or activating the diverter valve solenoid so that all boost pressure is immediately vented back into the intake tract.

EDIT: Confirmed. Same symptoms when revving in either park/neutral. Boost tries to stay on "0 bar", but briefly flutters up to "0.2 bar" when revving to 4,000 RPMS. Looked briefly online and this may not be a valid test. Some on the Audi boards are saying that turbo spool is based on load, which may answer why I can't build boost in neutral/park and possibly before the TC flashes. Need to do more research.

Either way, I am going to try to pin this down. Going to install a manual boost gauge next week that will tap into manifold pressure and bypass the stock boost gauge and will loop in Scott from Softronics if we need to revisit the tune to see if there is anything we can do.

This where a good tuner like Scott comes in handy! He understands the coding and can potentially be a lifesaver here..

 

I am sure you will figure it out , you always do