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Old 02-06-2001, 06:23 AM   #1
MBX Motorsports
Scooby Newbie
Member#: 3726
Join Date: Jan 2001
Location: Newark, DE
2001 2.5RS
Blue Ridge Pearl

Post Transmission & X-fer case strength ...

Ok, I'm about to start modding my new '01 RS. My question is, how strong is the drivetrain on this car? On my previous car, after lightly modding it, I blew the transmission (as in split the bell housing damn near in half).

Yes, I know how to drive stick, I've never owned an automatic ... so it's not a question of skills, it's more on how much extra HP can the stock powertrain handle before I'd have to build it up a bit? I want to add a 50 shot of NOS, exhaust, headers, CAI and a bigger TB once I get back from my wedding in March.

Thanks in advance for your help

2001 2.5RS
1977 Fiancee - Will trade.
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Old 02-06-2001, 09:19 AM   #2
Scooby Newbie
Member#: 3409
Join Date: Jan 2001
Chapter/Region: NWIC
Location: Woolley
1998 Ram 2500


If it's the STi transfer case well then, um, it's pretty darned strong. But unless you're going to go rock crawling with your Subie I'd just take it out and put a bottle of water in the trunk (to preserve weight).

The stock 5-speed seems to be the week link. Well, after the clutch. I guess what you'd want to do is upgrade the gears. I think that with little boost (5lbs?) it's ok, but I'm not sure about the nitrous. 50hp would probably be ok, but I think after that you start breaking stuff.

Anybody with experience breaking stuff wanna verify?
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Old 02-06-2001, 09:49 AM   #3
Scooby Specialist
Member#: 477
Join Date: Oct 1999
Location: Vancouver
GC4 -> GGA -> GM6
Yeah, that's about right.


... "a question of skills"?
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Old 02-06-2001, 10:38 AM   #4
MBX Motorsports
Scooby Newbie
Member#: 3726
Join Date: Jan 2001
Location: Newark, DE
2001 2.5RS
Blue Ridge Pearl


Necro - Yeah, as in knowing how to shift properly when racing the car, without beating the **** out of the gears. All I'm asking is, how much power can the stock drivetrain handle before it becomes prone to damage. (aside from the clutch, which I already know isn't the greatest) I'm talking about the gears in the tranny, the transfer case and the rear end. At what point would you have to strengthen those components?

I'm building my car up for 1/4 mile racing, and some auto-x. Generally, an all round faster car.
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Old 02-07-2001, 12:32 AM   #5
Homicidal Maniac
Member#: 1612
Join Date: Jun 2000
Location: Austin, TX
2008 STI


Heres my attempt:

The strength of the gearbox is still unknown. There are people that are running 10-12psi on stock gears while there are others blowing gears at 5-7psi. The general concensus is that if you do not abuse your gears, they will last some miles, but eventually they will let go. I think shiv lost his 2nd gear after 30k turbo miles at 10psi. Larry Ganz lost his 2nd after 2 months of turbo at 5psi (9psi briefly). There are probably more people with long lasting trannies with turbo than those with turbos and bad trannies. I _think_ that JC Sports stated that a legacy turbo half shaft will work in our tranny and strengthen up our weak gear. Basically, I just went ahead and budgeted in a tranny fix, since I know it'll go eventually.
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