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View Full Version : 200 r4 converter question....



hotrodgary
08-15-2005, 10:11 AM
I'm not that well informed on the 200 trans!

I'm thinking of running one in my chevy II, it has about a 550hp big block, and I'm not sure if the trans will hold up!!

My question is,My cam recommends at least 3000 stall....I think the max lock up converter you can get is 2500?

Do I need a lock up converter, or isnt it really necessary? What difference will it make, if I dont get a lock up will it be "slipping" while cruizing on the highway??

I could probably get away with a 2500, not sure though?

Thanks in advance, Gary

myclone
08-15-2005, 12:22 PM
I'm thinking of running one in my chevy II, it has about a 550hp big block, and I'm not sure if the trans will hold up!!

The 200 can be built into a fairly stout piece so I dont see why it wouldnt work in a fairly light car like the Chevy II with the moderate tq youre making. They have reliably gone low 10s high 9s in heavy buick grand nationals when properly prepped and using a trans brake.


My question is,My cam recommends at least 3000 stall....I think the max lock up converter you can get is 2500?

If memory serves me correct you can get lock up converters for this unit up to around 4000 rpm from ppl like precision. Its been quite a while since I looked at converter choices for the 200 so dont quote me on that.


Do I need a lock up converter, or isnt it really necessary?
Quite a few ppl use the non lock up converters for various reasons with no issues but an even larger number stick with the lock up to pull the RPMs down while loafing down the freeway at light throttle. It makes a pretty big difference in mpg if you drive the car a lot.


What difference will it make, if I dont get a lock up will it be "slipping" while cruizing on the highway??

Thats actually a very good question which most ppl fail to ask themselves before going non with a non lock up unit. It boils down to what your cruize RPM will be in OD with your planned rear gearing/tire diameter. If your cruize rpm, due to OD, is measurably lower than the stall rpm of the converter then you will get quite a bit of slippage during normal freeway driving which puts an EXTREMELY high level of heat into the fluid (thats bad). The lock up function eleminates that slippage so you can actually run a some what mild rear gear and enjoy the low rpm benefits (less wear/better mpg) without over heating the fluid.

On the other hand if youre running stump pulling rear gears like 4:56s with a short tire then your cruize rpm will be above the stall of the coverter so there is much less slippage and the fluid stays relatively cool. The only thing that will suffer is your wallet from fuel consumption LOL.

Some research on either one of the sites listed below should yield the information you seak as far as torque converters and who can build you a capable 200 to put up with some torque as well as track floggings.

www.turbobuicks.com (this site is the first one I would visit)
www.turbobuick. com (this site is owned by a 200 trans builder so be aware that you wont find any non biased info/suppliers here)

HTH

hotrodgary
08-15-2005, 12:55 PM
Thanks alot!!

I'm aware of the heat problem with high stalls and cruising speeds...it's kinda what determines a "streetable" car from a "Non-Streetable" car...I used to have a borderline streetable car...and it's kind of a headache! In my opinion that is!

I would like to stick with the lock up converter because thats why I wanted an overdrive, so I can take advantage of the highway cruisin!! I've done several cars and never ran an overdrive.

The car has a 3:50 gear and 28.5" tires, with a 3-speed it would probably turn around 3000rpm at 70mph. Not sure about the overdrive though?

Since I plan on puttin some miles on this car I think I would really like shiftin up one more gear for a change!!!

Gary

JMarsa
08-18-2005, 12:33 PM
Try this on:

http://www.dalesplace.com/htm/information/rpm_calculator.htm

Your RPM looks about right.

If I remember correctly, the 200R4 has a .67 overdrive. 3000 x .67 = 2010 RPM with the newer trans.

--JMarsa