Automobiles Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
17,178 Posts
Discussion Starter · #1 ·
what would be a good A/R ratio for my MC motor. I'm gonna have a header, i know that will make a difference. any suggestions on trim size and what not?
 

·
Registered
Joined
·
2,692 Posts
derracuda said:
what would be a good A/R ratio for my MC motor. I'm gonna have a header, i know that will make a difference. any suggestions on trim size and what not?
What kind of turbo? Garrett? KKK? Holset? IHI?......?
Mike
'88 VW "R22"
 

·
Registered
Joined
·
17,178 Posts
Discussion Starter · #3 ·
i''m probably just goin' to go with a garrett. and I would like a water cooled unit. I know it's not necessary, but I still would like that feature for longevity.
 

·
Registered
Joined
·
2,692 Posts
derracuda said:
what would be a good A/R ratio for my MC motor. I'm gonna have a header, i know that will make a difference. any suggestions on trim size and what not?
Now that I think about it, I guess I can probably safely assume you're interested in a Garrett. I'm also going to assume this is street driven, you want boost around 3000ish RPM, power band from 3500-6500ish. If this is wrong, correct me.
I'd suggest something in the Garrett GT series. The question is, do you want to spend $550 for your new turbo, or double that.
The T series turbos are going for about 550 right now, whereas the GTs are around and over $1000.
Okay, enough rambling.
You have a choice between a T3 exhaust side with a T4 compressor (hybrid) or a straight T4. If you were going to use a T3/4 hybrid, you'd want to go at least with a .63A/R housing with a "Stage III" exhaust wheel. The standard T3 wheel has a 1.9" exducer, whereas the stage III has a 2.23" exducer (same size as the MC exhaust wheel, but a more open design). A stage II wheel is also available, with a size in between. So the housing has the same aspect ratio, but with the bigger wheel, the stage III will flow a lot better. Probably a good compromise (low rpm response vs. low back pressure) for a street car.
Or you could use a T4 exhaust housing along with the T4 compressor. In this case, you can get an N, O, or P trim exhaust wheel. The N trim has a 2.07" exducer, the O trim is 2.3" while the P would be too big at 2.55".
Best match here would be a O trim wheel, with either a .50A/R or a .58A/R exhaust housing. Take note, that the A/R can not be compared between the T4 housings and the T3s, both A and R are bigger on the T4.
Since it's been used quite a big, and proven to be pretty damn good, the .63A/R Stage III T3 hotside with the 50 trim T4 compressor should be a great match. Costs $549 currently, and flows enough for about 450hp.
Good luck!
Mike
'88 VW "R22"
 

·
Registered
Joined
·
2,692 Posts
derracuda said:
i''m probably just goin' to go with a garrett. and I would like a water cooled unit. I know it's not necessary, but I still would like that feature for longevity.
Ahh okay, with water cooling it'd cost $630 or so. Still a deal compared to a few years ago.
Mike
'88 VW "R22"
 

·
Registered
Joined
·
17,178 Posts
Discussion Starter · #6 ·
where can i get one for this sum of $549 8)
 
1 - 7 of 7 Posts
Top