Inliners International Forums General Discussion Drive Train Is this possible?

After reading up on converters here and elsewhere , I am trying to learn more about converters. I know that hot street and race cars have much higher stall speeds than stock. My limited experience seems to be that a high stall converter is "sloppy""on the street. One way around this is to run a lockup trans but I don't have one. Is there a way to have a little more stall speed and be tighter on the freeway when you are up to speed? Anyone have any experience to share would be greatly appreatated. As near as I can tell my stocker foot brake stalls around 1500 rpms and seems to flash stall around 1700. Thanks in advance. Jay 6155

There are converters that will drive like a stock converter, that is until you nail the throttle then the RPMs go up quickly!

True, also, there are poorly made converters & just feel like they slip all the time & will really make your MPH drop in the 1/4 or 1/8 mile.

I hear good things about YANK converters, there are others also that perform really well in the street & don't feel loose.

A lot of times, when it comes to converters, you get what you pay for.

Most good converter companies, will tweak your converter for free if you are not happy with it. Usually a one time deal though.

MBHD

That's what I am looking for. One that seems very close to stock for normal driving with good performance when you nail it from a stop. Maybe 3-500 more than stock. Believe it or not I can't foot brake stall past 1500 rpms before one of the rear tires breaks loose. I think that one of my back brakes is badly out of adjustment! I will try to do some more testing with a better tach and fixed rear brakes. Jay 6155

I believe it.
My Silverado brake stalls @ 1200-1400 range.

Depending on where your vehicle is destined to go to , back east, west etc, there are different converters w/different stalls.
My friend found this out when looking for a different converter for his 2001 GMC mid size truck.

He had told me the stalls for his particular truck could range from 1600-2100 or so stall, with different letter codes stamped on the converter.

Not sure if the older cars GM did this, I do not think so, but who knows?

You could call Yank, http://www.converter.cc/default.asp
& tell them your combo, what HP & torque your engine produces, rear gear ratio, weight of car etc, so they can have a better idea of how to make your converter stall the way you want.

I think a 12" Saturday night special "TCI" http://www.summitracing.com/parts/tci-241500-a/overview/
would work OK for you.
The 2000 stall advertised, you probably will not see a 2000 stall, probably would see 1600-1800 brake stall, that being said, with this type of a generic converter, (mass produced) you would be better off w/a an advertised stall of 2300-2400 from TCI or B&M etc.

I think a Yank converter will drop your ET's down lower, but not sure exactly what you want out of the converter change?

My Moms 1999 Olds Intrigue 3.8 liter V-6 back stalls too 2800 RPM IIRC, & when you drive that car, it drives like any mundane ho hum V-6 car, but when you nail the throttle it takes off pretty good considering it is by no means a race or fast car.

In my Camaro I have an Old Darrel Young 10" AKA (Darrel Junk) 3500 stall torque converter, the absolute highest brake stall I ever seen was 2800 RPM, my 250 6 just never made enough low RPM torque to stall it that high.

If you put that same 3500 stall 10" converter behind a decent 350 SBC, it would more likely stall to 3500, because that's how it was rated with, a SBC 350 in mind.

An efficient converter will not make you lose too much MPG, but adding a higher stall will always drop your mileage.

MBHD

I also foot brake stalled our 4200 Trailblazer and came up with a 25- 2600 number. This time the brakes held and the truck did not spin. I have heard and read that having a good well made converter is one place to "spend the money" and not go cheap or off the shelf. I don't need a super strong unit because of the low HP the engine porduces compared to say a BBC. Even the new engine will only just kiss the 200 HP mark. I will contact Yank and TCI and see what they say. Maybe an off the shelf unit is what I need. Jay 6155

One option that was always available was the stock Vega converter. It would allow a stall speed around the 1500-1800 mark without breaking the bank back in the day when converters were more expensive.

Here in the rust belt ( Ohio) I haven't even seen a Vega in years. Maybe a stock replacement Vega converter could be had, I don't know. Anyone know how they do at freeway speeds? Years ago a neighbor ran a Vega converter in a mild 350 Cutlass drag car. Very constant low 14s. Was a nice bracket car. So far it looks like one of those 2000 stall "towing" converters might be right for me. Anyone have any experience with Hughes or B&M ? Jay 6155

You could buy them from places like NAPA and others before AutoZone and Advance auto parts were even around.

I bought a new rebuilt Vega 10" converter years ago (15-20 years ago) (about $60-$80 dollars back then) for my 250 -6 Camaro.

IIRC, I got about 2500-2700 brake stall, it actually work pretty good, did not feel all mushy when just driving around.
I had 4:10 gears & car weighed about 3300 LBS.

It did break after about 2000-3000 miles, it could not hold up to my manual valve body TH350 trans.

One of my friends used a B&M 3500 stall 10" nitrous converter.

He could only get 2800 brake stall & this was on a 385 SBC Bowtie iron heads 10.25:1 compression & 3800 LB car.

When running a NOS "cheater " plate system, we ran the 175-200 HP jets & then the converter would flash stall to 3500.

He asked to re-stall the converter @ B&M, they said bring it in for a free re-stall, he never got around to bring it in.
Best time in a 4000 LB Camaro 11.36 @ 119 MPH This was about 20 years ago.

I have heard the B&M's are tight converters & do not feel mushy, for the most part.

I would pick a Hughes over a B&M J.M.O.

MBHD

Thank you for all the info. Looks like what I am trying to do can be done. One of the "rules"that I have read about is not to have a stall speed above the 60 mph or so cruise rpm of the converter will not "lockup" and will generate too much heat. I am not talking about a clutch type converter used In later model transmissions. MBHD, I am sure that with 4.10 gears that wouldn't be a problem! Without overdrive that engine had to be wound pretty tight on the freeway! With the turbo engine that you are building isn't a lower stall speed called for? Jay 6155

Yep, 4:10's on the freeway was/is horrible. I absolutely hated it.

When I get the car geared up for a turbo, I am thinking I will get 3:20-3:40 rear gear ratios. Depending on what tires I can fit.

As far as the stall for the old freshened up turbo engine I will be building, it depends on camshaft & turbo's A/R of the turbine housing.
But for the turbo & camshaft I currently will be using, I am sort of guessing I need 2600 stall for my .63 turbine housing, & for the .84 turbine housing a brake stall of 2800-3000 stall would be good.

For when ever I build my good turbo specific 12 port 250 engine, I am thinking I need about 3600 stall.

I am not going for gas mileage, but will have a lock-up converter & OD trans.

MBHD

That surprises me that with a turbo that the stall speed would be that high. I will be the first one to admit that I don't know anything about how to set one up, but I always thought that if you loaded the engine sooner that boost would build faster. Do you need to get the engine wound up to 25-3000 rpm to get enough exhaust flow to spin the turbo for initial boost? I have not eliminated the possibility of going with a 350c with a lock up converter.Still looking around to see what I can find. Jay 6155

You can have a low stall converter w/a turbo, but if you have too big of a turbine housings A/R , then it will have turbo lag, meaning you will not see boost until you have enough exhaust flow to spool up the turbo later in the engine upper RPM range.

Or by having too large of a turbine wheel, (heavy) too large of as compressor wheel, a lot a variables to consider for sure.

Camshaft having too much overlap. Low compression, incorrect timing, etc, etc, too large of volume intake manifold, runners too big, header tubing too large.

My Syclone has a stock torque converter w/a known brake stall of 2100 RPM.
When stock, when you floored it, there would be turbo lag until about 2400 RPM, then it would see a couple PSI of boost pressure. Full boost (14.5 PSI) by about 2800-3000 RPM

But, you can also hold the brakes, give it throttle & boost launch it, so when the RPM's would go to 2100 PRM, you can see the boost creeping up, hold the brakes long enough, then you could launch @ 15-20 PSI of boost pressure w/out even moving yet, release the brake pedal, BAMM! boost launching an AWD truck @ 15-20 PSI, & cutting 1.6- 1.7 second 60 ft times w/standard radial tires, is a pretty good feeling for a stock 3600 + lb pick-up truck.

Depending on a turbos engine combination, you can have turbo that can see boost pressure at 1500 RPM, but will be severely choked up on the exhaust side from too small a turbine wheel & turbine housing.

If you want a torque converter w/a lockup feature, I would consider using a different transmission.
I personally like the gear spacing on a 200R4 trans, it will make your car quicker, has a OD 4th gear usually = better mileage & it is a direct replacement, meaning, you do not need a different driveshaft made, or cross member, you do need to have a bracket as to use the TV cable. Probably need to get a Holley linkage kit for the 700r4/2004r TV cable.
If you do not plan on making any serious high HP/torque 250 6 cylinder, this would be a good option for you.
The 200R4 can be built up to take more HP/torque, but it will cost you money.
The 200R4 trans were used on all Buick Grand Nationals & Turbo T-Types & those put out about 300 HP stock to the wheels.
Those trans used in those cars were the better ones to use stock for stock, but they had the B.O.P. engine bolt patterns. So you would need one that have a Chevy bolt pattern housing.

A member here (TheSilverBuick) has a 200R4 in his Firebird, so he knows how the 200R4 works on a inline 6.


MBHD

From the way you talk, turbo size is a bit like picking a camshaft, boost down low somewhat chokes exhaust up at higher rpm. Too big a turbo and low rpm boost suffers. I have thought about a 2004r or just a 200c swap. With the od trans I would be ahead to change the 2.73 gears to something lower. Just have to see how it goes. The best 200-4r for me would be one out of a months Carlo ss. Still kicking it around. May just put in a converter and teach my grandson how to install a shift kit and call it a day. Jay 6155

Got to talk to someone at Hughes today. Very helpful. Told Pete at Hughes what I had and that I wanted a little higher stall speed for take off and a tighter lock up feeling on the freeway. He said that they would have to custom make me one to get the best of both worlds but it wouldn't be any extra cost. What I have to do now is get under the car and see which converter I have now to help decide what size to go with. Pete had the specs on all stock converters used in my car. There is a 6 cylinder 11.75 inch a 6 cylinder 12.5 inch. And a v8 12.5 inch. A width measurement. And the type of mounting ears will tell what I have now. Once that is known we can go from there as to what size I need. I will let everyone know what I find out. Jay 6155

What trans are you asking about for a converter?

MBHD

I have a TH 350 in the car. That's what trans I talked to Hughes about. They also have some " switch the pitch" converters for TH 400s they can build if I wanted to go that way. We also talked about the 2.74 first gear set that they sell for the 350 trans. Buying and putting in a th200 would be cheaper than the gear set. Jay6155

Installing a 200R4 would make a huge improvement over your TH350.

A switch pitch TH400 would be OK, but a bit overkill & power robber for you application.

Just think about it, you can run 3:73 (or so) rear gears, accelerate will be a day & night difference, & still knock down the RPM's for freeway cruising & better MPG's.

No driveshaft needed to install a 200R4 & from what I read, reposition your stock cross member.

From what I remember the 2.74 gear sets fro a TH 350 are pricey & more importantly are weak.
I also contemplated that gear set also for my TH 350.

The main reason I did not look further into getting a set was that they are weak & are weaker the a stock gear set.

MBHD

MBHD, you have some very good points. I had a car with a switch/pitch trans. Put a switch on the dash to change the pitch. A lot of fun, could lay rubber for a city block easy. To do that now would be a lot of work. I would have to get a BOP TH400 and put the parts to make it work in a Chevy case. Not to mention the shortened driveshaft, and the power loss through the trans. I did not know that the aftermarket 2.74 first gear was so weak, thanks for the info. I do know how much they cost, a lot. I have thought about a 200-4R, don't know if I want to change rear gears or not. Another possibility is a TH 200 or TH200c, you get the same first three gears as the 200-4R, also a bolt in. I know that t he car would be quicker with 3.73 gears, just not sure I want to go that route. Do you or anyone else know how much Hp it takes to run different auto trans? How much more does a TH 400 "cost" to run compared to. 350 or 200 or 200-4R? Jay6155

I just looked up some old posts and according to the "Deuce Coupe Gonkulator" I wouldn't gain much from a 2.74 first gear either with a new gear set for the 350 trans or bu putting in a TH 200/200-4 R if I left the rear end alone with a stock type converter.

It would not be a huge gain, but a gain would be had for sure.
A gain you would feel.

Part of the reason I mentioned to change your rear gears also.
Also, you would not want to use OD on a 200R4 trans w/your current rear gear ratio, unless you would like to use it when you are going above 85-90 MPH? High speed low RPM cruise anyone?

IIRC, your gear ratio is pretty bad for performance. What are they again, 256,272's?

It would be a big gain if you have a PG trans & switch to a 200R4 w/all else being stock.

If you were to switch to some 373's & a 200R4 w/a high stall lock-up type converter, what would the Gonkulator say about that difference?

Deuce Coupe ?

MBHD

I have 2.73 gears now. According to Deuce Coupe, if I went to 3.73 and a 2004R and 2500 rpm stall converter I would go over 1 second faster in the 1/4 mile with no changes to the engine. Jay 6155

That is a huge gain for not doing a thing to the engine.

MBHD

When I built The Frenchtown Family Truckster drag car I did some computer modeling using a 4000 stall converter and either 2.47 or 4.56 gears in the rear end. The computer said 11.60s with the 2.47 gears and 10.90s with the 4.56 gears in. I never put the 4.56 gears in (that was going to be for the NHRA 10.90 heads-up class, which I haven't pursued yet) but it did run a 11.61 w/ the 2.47s.

If your current converter is stock - assuming around 1200 RPM - you'll see a sizeable reduction with both the gear change and the stall speed change. I wouldn't bet the farm that it will be a full second but it wouldn't shock me if it was.

One of the big "ifs" is whether you can avoid excessive wheelspin, which may entail taking a look at better tires and rear suspension mods. One performance upgrade often necessitates changes to other aspects of the vehicle.

Even though my current tires are 195/75R/14 there is no danger of excessive or any wheel spin HA HA. I have better tires for later when I get new wheels. I think that gearing the car tocross the finish line at the top of second gear might be a good idea. Any thoughts? I also wonder how much of that second gain comes from the gear and how much from the converter? Jay6155