What torque converter for 99 TA with STS turbo?

**rick67** · 07-11-2009, 09:38 AM

Hello all
I'm a long time 60's big block musclecar guy with my first turbo car. It's a 99 Trans Am with a single Squires rear mount turbo.
For one thing, it's the newest hot rod I've ever had (by about 30 years!) so sorry in advance for all the stupid questions I'm probably going to have in the coming months. The miles of hoses and wires under the hood are a little intimidating to me, and the whole "turbo thing" is completely new to me.

But anyways, I love the car!! All the comforts of a new caddy with the bite of some old detroit iron! It's running about 5-6 psi and the only other mod to the car besides the turbo is larger 48lb fuel injectors and a tune. I haven't had it to a strip yet, but the previous owner said it runs mid 12's. I did do a blast with my old gtech and I trapped 116.x MPH so I'm guess mid/high 12's is about right??

With that said... it's a dog out of the hole. The turbo doesn't kick in till about the top of 1st gear. I'm thinking my first mod will be a torque converter.

Any recomendations? Using old-school logic I'm thinking something around 2500 RPM stall speed?? What about lock-up?

Penny for your thoughts...
Thanks in advance!

***Ed Blown Vert*** · 07-11-2009, 09:50 AM

Don't get anything lower than 3000. All the new style converters have lock up.

Without knowing your powercurve and when you get into boost. I would say in the range of 3200 - 3600.

I run a 3200 Vigilante. Sometimes I wish it was a 3600.

**rick67** · 07-11-2009, 09:56 AM

Originally Posted by Ed Blown Vert

Don't get anything lower than 3000. All the new style converters have lock up.

Without knowing your powercurve and when you get into boost. I would say in the range of 3200 - 3600.

I run a 3200 Vigilante. Sometimes I wish it was a 3600.

Thanks for the input Ed!

The reason I was thinking lower was because of the cruise RPM going down the road. I've always thought you should try to keep your cruise RPM above the stall of the converter? But maybe that's what the "lock up" does??
I've never specifically looked at it, but I bet I'm around 2000 rpm going down the highway at 65.
Will that hurt a 3200 stall converter? I like to drive this thing alot and will put alot of long trips on it.

Thanks again for your time

***Ed Blown Vert*** · 07-11-2009, 10:00 AM

The lockup will solve that. It will lock up at round 45 mph.

So you could even run a 4000 - 4400 and it will lock up and drive normal on the highway.

At what RPM do you get into boost?

**rick67** · 07-11-2009, 10:16 AM

Thanks for the info.

Not sure what RPM the boost kicks in. I haven't specifically looked at that. I'm still just learning to get the "feel" of the car. Way different than a 60's big block!

It seems like the boost is "all in" towards the top of 1st gear, which is probably about 2 seconds after I punch it??
I'll have to do some "research" on the back roads and get back to you.

***Ed Blown Vert*** · 07-11-2009, 10:23 AM

The converter will take care off all the lag

**rick67** · 07-11-2009, 12:29 PM

Thats what I'm hoping!

My goal is 11's.
Assuming it really does run mid 12's right now, 11's should be reachable with a converter and a meth injection kit so I can add another 2 or 3 psi of boost, and then finally a new tune to take full advantage of the extra boost.

At least I hope that'll get me into an 11.9X or better, because that's about as much as I'll want to modify on this car. I don't want to lose ANY streetability... and I'm not made of money. haha

***Ed Blown Vert*** · 07-11-2009, 12:36 PM

Don't worry it will. The converter is the best mod for an A4. And always should be the first.

When you step on the pedal, it will move. Just make sure you have the tires to support it.

I ran Nittos for a while. Had to switch to ET Streets. Still not enough traction on the street.

**rick67** · 07-11-2009, 01:14 PM

I just put some Drag Radials on it last week.
Before, when the boost would kick in at the top of 1st, the tires would stay "loose" all the way through 2nd and part way into 3rd. Not smoking them... but definately "loose".
Not anymore...

***Ed Blown Vert*** · 07-11-2009, 01:51 PM

That will change. Before the blower, just on Nittos and a converter. I couldn't hook. It will be a different animal with it.

**JwMonE99** · 07-11-2009, 03:18 PM

Why nothing under 3,000?
Is it because its turbo or a typical rule of thumb?

**c5z28** · 07-11-2009, 04:11 PM

Originally Posted by JwMonE99

Why nothing under 3,000?
Is it because its turbo or a typical rule of thumb?

Flashes you up into your powerband our powerband is not in the 2000rpm range.

**rick67** · 07-14-2009, 07:16 PM

I got my new Gtech today and did some playing.
I made 2 runs.... 12.76 @ 114 and 12.77 @ 113
60' times were 2.20 both times

That 60' time doesn't belong with those ET's! My last car was a 67 Buick GS ragtop running 13.50's at around 100 with a 1.8 60' time. Crazy stuff in this turbo world! haha
Any educated opinions how much of a gain I should expect from a 3200-3600 converter?
(60' and/or ET)

I did quite a bit of reading here the last 2 nights on 4L60E torque converters, and they are much more expensive than the ones I'm used to buying for my trusty TH400's over the years. I would like to have a decent estimate of what my reward vs. investment will be.
Thanks again to all for your advise and opinions!

**Frost** · 07-15-2009, 04:45 PM

You want it loose enough to foot brake into boost on the line but tight enough to keep flash to 5K with that turbo setup. I would think that would mean something like a 4K stall to be able to 'get it up' in first. The extra boost and methanol with retuning is an excellent idea. The meth is good stuff!

**rick67** · 07-16-2009, 03:02 PM

Originally Posted by Frost

You want it loose enough to foot brake into boost on the line but tight enough to keep flash to 5K with that turbo setup. I would think that would mean something like a 4K stall to be able to 'get it up' in first. The extra boost and methanol with retuning is an excellent idea. The meth is good stuff!

Thanks for the input Steve. I'm hoping to be able to do all these mods yet this summer. But cash is an issue. I'm "this close" to having my Mustang sold.... maybe this weekend. When that sells, I'll have the cash.

Any guess on what kind of performance improvement I can expect from just the converter? Anyone with experience with a combo like mine? I'm leaning towards the 3600 for what it's worth.

**rick67** · 07-21-2009, 01:12 PM

Well.... sold the Mustang today, and I also spoke with Dave at Yank today about my car.
He recommends the Pro Yank 3600 converter and that's what I'm going with.
The local Pontiac nationals is coming up in about 2 1/2 weeks so I won't have a chance to get it installed before that. I don't want to risk something going wrong during the install and not having the car race-ready for the event, but I'll hopefully have it installed within the next month or so. I'll post my results for some "Real world" numbers as to exactly how much ET/MPH improvement just the converter makes with my combo. I won't make any other changes to the car until after I try out the converter.
Can't wait!!!

PS... and just for the record... I did make it to a track last week and the best I could muster was a 13.06 at 103 lifting and still breaking out. Through-out the day I ran 13.10 @ 112, 13.11 @ 111 and 13.12 @ 111
Strange that I was running so much faster during 3rd round that I lifted 9 MPH and still broke out.
Oh well.
Anyways... the benchmark has been set. Lets see what a 3600 Yank can do without any other changes!

**98Camarod** · 07-26-2009, 06:48 AM

Any update on your times?

**rick67** · 07-26-2009, 12:37 PM

Originally Posted by 98Camarod

Any update on your times?

Nope, I got an email from Dave at Yank yesterday. My converter is shipping Monday. It won't get here until late this coming week, and with the Pontiac Nats the following weekend, I'd be too scared to put in the converter with only a week to get it back together and sorted out. I'll wait until after the Pontiac Nats to put it in.

I've also been in contact with STS about a meth kit. They have meth kits and boost controllers avaliable. I'll be ordering that next week too.
My plan is 5 PSI without the meth turned on, and 8-9 PSI when the meth is turned on.

**98Camarod** · 07-26-2009, 01:07 PM

Originally Posted by rick67

Nope, I got an email from Dave at Yank yesterday. My converter is shipping Monday. It won't get here until late this coming week, and with the Pontiac Nats the following weekend, I'd be too scared to put in the converter with only a week to get it back together and sorted out. I'll wait until after the Pontiac Nats to put it in.

I've also been in contact with STS about a meth kit. They have meth kits and boost controllers avaliable. I'll be ordering that next week too.
My plan is 5 PSI without the meth turned on, and 8-9 PSI when the meth is turned on.

There isn't anything to work out really when you put in the converter. It can be done in a few hours with a lift and and add another hour or two without a lift.

**TOMASINO** · 07-26-2009, 01:36 PM

Originally Posted by Ed Blown Vert

The lockup will solve that. It will lock up at round 45 mph.

So you could even run a 4000 - 4400 and it will lock up and drive normal on the highway.

At what RPM do you get into boost?

i just installed a 3200 from yank but i don't get any lock up only on ''D'' is this normal??after 50 mph but if i drive on 3rd tranny goes completly neutral