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-   -   Back to back comparison of Th350 and Metric 200??? (https://classracer.com/classforum/showthread.php?t=54182)

FLEMING 07-29-2014 09:12 AM

Back to back comparison of Th350 and Metric 200???
 
Has anyone done a back to back comparison of a good th350 to a good metric 200? I have heard the metric is a solid tenth faster...

I am looking at purchasing a combo with trans and convertor but I may pass on the trans/convertor and just buy the engine if the metric is really worth the difference..

Also does the metric use the same crossmember as the th350?

jim powers 07-29-2014 09:32 AM

Re: Back to back comparison of Th350 and Metric 200???
 
same crossmember, depending on your combination a solid .12 should be the result

Dion Hildebrandt 07-29-2014 09:40 AM

Re: Back to back comparison of Th350 and Metric 200???
 
I did this change and a solid 7 hundredths was discussed, my actual improvement is undetermined because I made a few changes at the same time.

a stock 350 gear was a 2.52, and the metric low is a 2.74. I saved 60 pounds just changing the transmission. the 60 foots changed dramatically

Stock crossmember, same driveshaft, same shifter and for me same convertor (I have a 350 input shaft)

I had almost 200 problem free passes before I had the trans opened up. This is in a 3500 pound small block chevelle

FLEMING 07-29-2014 09:42 AM

Re: Back to back comparison of Th350 and Metric 200???
 
I have heard you only get about 75 to 100 runs out of metric gearset?? Is that true? Also I have heard that you need to not let the tires "chirp" coming out the burnout as this will break them?

Mike Taylor 3601 07-29-2014 09:44 AM

Re: Back to back comparison of Th350 and Metric 200???
 
Randall's truck picked up.30 or .35 it had the 4.3 then you would have to ask him about the 350 he took out had done,but I do know the 200 has manual valve body and that is about it.

I say that probaly isn't normal gain
Don't want to jinx him but I know several times Randall has put over 200 passes,only time he has broke is when he broke ring and pinion,bust sprag/planetary Mike Taylor 3601

Dion Hildebrandt 07-29-2014 10:01 AM

Re: Back to back comparison of Th350 and Metric 200???
 
I may be doing the burnout wrong , but I have had no issues doing it this way
-roll into the box with shifter in 2nd (auto 1-2)
-bring rpms up to 5-5500
-once rpms have been reached let go of the line lock and roll out until tires grab
I run radials and haven't had any traction problems either.

recently I had a modulator come apart but that has been the only issue with this trans.

- I should note that when we had the trans apart, we could have reused all of the frictions and steels. Gears all looked fine, or new like

FSA1673 07-29-2014 03:24 PM

Re: Back to back comparison of Th350 and Metric 200???
 
It was worth 0.15 to 0.18 in my car. My Metric 200 trans was 35 pounds lighter than my old Turbo 350. I purchased my Metric 200 through the Sepanek's. They build a good reliable trans and are fantastic people to deal with.

Thanks, Scott

Alan Roehrich 07-29-2014 06:45 PM

Re: Back to back comparison of Th350 and Metric 200???
 
It would be interesting to know what was in the TH350 transmissions used for comparison. There is a considerable difference between an "average" TH 350, and a lightweight SLD type transmission from a company such as ATI, or as I build with ATI components.

Greg Hill 07-29-2014 08:50 PM

Re: Back to back comparison of Th350 and Metric 200???
 
On my car it was .04 to .06 better, but I had a really trick 350 that had a rotating assembly as light as a stock 200. I think the higher the hp and torque the less difference.

Alan Roehrich 07-29-2014 08:57 PM

Re: Back to back comparison of Th350 and Metric 200???
 
That's what I'm getting at Greg.

Compare the Metric 200 to a 350 with aluminum forward and direct drums, lightened front and rear planetaries, a 250C sun gear shell, a gun drilled output shaft, and all roller thrust bearings.

I've seen a lot of claims about ET reduction of various transmissions. I can tell you that I built a killer 350 for a well known and successful Stock Eliminator racer a few years back. A couple of years or so later, he was told that a certain high dollar transmission would be 0.07 to 0.12 faster. He spent a lot of money, and he may have knocked 0.03 or so off of his ET. It was a big block car with fairly high HP, about 3700 pounds or so.

Ed Wright 07-29-2014 09:38 PM

Re: Back to back comparison of Th350 and Metric 200???
 
I would expect the only legit comparrison would be with the same gear ratios. You can get about any ratio you want for a T350 now.

Bob Mulry 07-29-2014 11:01 PM

Re: Back to back comparison of Th350 and Metric 200???
 
Quote:

Originally Posted by Alan Roehrich (Post 439822)
That's what I'm getting at Greg.

Compare the Metric 200 to a 350 with aluminum forward and direct drums, lightened front and rear planetaries, a 250C sun gear shell, a gun drilled output shaft, and all roller thrust bearings.

I've seen a lot of claims about ET reduction of various transmissions. I can tell you that I built a killer 350 for a well known and successful Stock Eliminator racer a few years back. A couple of years or so later, he was told that a certain high dollar transmission would be 0.07 to 0.12 faster. He spent a lot of money, and he may have knocked 0.03 or so off of his ET. It was a big block car with fairly high HP, about 3700 pounds or so.

And don't forget the extra $500 for the 2.75 low gear set for a TH-350, which comes as a 2.74 low gear as standard on a TH-200......

Aluminum direct & forward drums, a 2.75 low gear and the lightening of the gear sets make this a more expensive trans than the TH-200.

Just my thoughts,
Bob

Alan Roehrich 07-30-2014 12:14 AM

Re: Back to back comparison of Th350 and Metric 200???
 
That assumes you want or need the 2.75 low, which is not always the case. And if you don't want the 2.75, you have to go with a custom gear set for the 200.

If the 200 is not substantially faster, then the only advantage would be cost, and with the added durability of the 350, it becomes a wash. We've got the same stuff on the 350 that has been in it since 2007, for a lot of passes.

The 200 is not that much cheaper if you need or want the bigger input shaft and stator shaft, so you can use the turbo converter and/or need the strength.

The 200 is not a tenth faster than a really good 350 in many cars, I talked to Scott McClay about it, and I'd say he knows as much or more about it than anyone. The more power the engine has, the smaller the ET reduction, and the heavier the car, the shorter the lifespan. For example, Scott told me that in our big block Camaro, he'd expect no more than 0.03 quicker with his best 200 vs my 350, at best. Thomas Arnett and I have talked about it for a while now, he's not sure he could get more than 0.03, either, he runs a 200 in his car, similar to ours. We've been meaning to try it.

FLEMING 07-30-2014 08:32 AM

Re: Back to back comparison of Th350 and Metric 200???
 
I guess I need to see whats in the th350 then... it is a turbo action piece I know that much.. Its a low horsepower mid 70's 350 combo (i think 185hp)... I have a 4.88 in my car do I need to go 5.13? I have NEVER ran anything other than a powerglide so this is going to be interesting going from a 1.80 low gear to a 2.5+ first gear.. lol

philbilly 07-30-2014 09:10 AM

Re: Back to back comparison of Th350 and Metric 200???
 
Not quite a tenth in the crate motor car Steve. That is using the same converter. Most can't switch the converters. It's about another grand to get the metric to take a turbo converter.
On a side note reverse is really week.

Todd Hoven 07-30-2014 09:20 AM

Re: Back to back comparison of Th350 and Metric 200???
 
If your going to spend money on a really good T350, lightning, low pressure, pump and VB, aluminum drums throughout, you might as well buy a pro trans.
The 200 close to stock form, is at least a .10 faster than a 350, unless the 350 gets 4k worth of upgrades.

There are 200's in everything from comp cars to stockers these days. They are very reliable, and durable. For a lower power stocker it should be a win - win.

j gardiner 07-30-2014 01:55 PM

Re: Back to back comparison of Th350 and Metric 200???
 
I went from a t350 with a 2.75 low gear and no lightweight parts to a t200 and saw only about a .02 difference after subtracting the weight difference. I also changed the convertor witch adds a variable. This was behind an olds engine.

5389stk 07-30-2014 10:01 PM

Re: Back to back comparison of Th350 and Metric 200???
 
My experience, mcclay 200 w/turbo input vs 350 2.75 low, light drums 67 impala, 396/325 at 4270 pds . Same track ,same converter, same day, da with in 150 ft ,,t350 11.86..11.87 ..11.87 ..[.t200.]..11.73...11.74 ..11.73. . 200 .13 to.14 better . Trans was used in 427 b/sa chevelle for 5 years when i bought it. Replaced low gear clutches, updated pump in 08 . Been perfect till blew u-joint last year cracked case not trans fault.


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