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Discussion Starter · #1 ·
Alrighty. I'm turbo shopping. I'd love a T28, but I'm having a helluva time finding a KA24DE manifold with a T25/T28 flange. The T25 would probably be a little small, but it has the quick spool, low RPM characteristic that I like for auto-x. And I'll just get a giant intercooler to help the top end. :roll: With enough fuel, its good for up to 300 rwhp @ around 10 psi.

However. My best (or easiest) option right now is T3/T4/T04E, since there's a stainless steel, equal length manifold goin' for $350 shipped. So, is there any possible way to make a quick spoolin' T3/T4...or just a straight T3? Maybe a very small turbine side? :suspicio: I should probably read my book from Corky Bell, but I'm too lazy to peruse right now. :) Plus, you guys need some finger excercise. :p
 

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With a 2.4l motor, you won't have any problem spooling many of the variations of the T3/T04/e. I would go with a .57 comp. and a T04e comp. housing. If your trying to get 300rwhp, I see no other way than to go with a .63a/r hot side. I have a buddy running a T3 60-1 on his 240. It spools plenty early and has the top end to match(T3 60-1 is even bigger than the turbo I just spec'ed for you). Note though, the smaller the a/r on the exhaust turbine, the quicker the spool.....but the less topend power you have. It won't flow at higher rpm as well.
 

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Far and away the best way to pick a turbo is too copy someone else's success. The variables are way too complicated to put it on paper and get anything useful at the bottom line.

Be careful reading the Bell book on this subject - it's really written with turbocharging big American iron in mind so some of the generalizations will set you down the wrong path.

If you want to spend some more bucks, you'll have more success with one of the newfangled Garretts at that power level like a GT28RS (which you can get with a T3/T4 style exhaust housing for that manifold). 300rwhp ain't a lot for a 2.4L.
 

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No, 300rwhp isn't alot, but the 240 head is an absolute joke. Damn motor is pretty much a truck motor, so it isn't designed with hp in mind. Getting 300rwhp with 10psi will be quite a challenge.
 

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Discussion Starter · #6 ·
Bench flows show that the KA DOHC head actually outflows the SR20DET head.

Here's an intercooled T25 w/ proper fuel delivery...pretty sure its at 10 psi:



With the higher RPM effiency of the T28, it seems pretty achievable to me, no?

Not that the T28 is really an option right now...unless I find someone to make me a manifold. I'll probably be lookin' at the T04e that you mentioned above. T3/T4 hybrids are actually pretty common among the 240 kids...but we'll see how original I can get to get that low end spool. :weirdo:
 

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Discussion Starter · #7 ·

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That torque curve doesn't take a steep enough dip to make me think it's running too far off the map. I don't have a T-25 compressor map, but that's just not a lot of demand. Do you have a T-25 map? It's also not true that you can always make more power by using a bigger turbo at the same boost because your VE will take a dive up top without headwork. You'll generally need to run *more* boost to maintain torque higher up. I.e., don't expect to be able to strap on a big turbo and have a torque curve like the one shown just pushed further up the range.
 

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All I know is my buddy is running a turbo 3 times the size of a T28 and he is also running 10psi. He makes 220~230ish-whp and he is using the Greddy E-manage for a tune. He uses the Tech-Edge Wideband and has her dialed in for mid/low 11s. So, I am going to say that thats an anomalie. There are always those people out there who make great power with a less than stellar setup, but don't take those numbers as the norm. Also, another variation could be flow the flow benches. If I recall correctly, the heads need to be tested on the same flow bench as some benches use less water than others, which can change the numbers. That does surprise me that a truck motor could outflow a 8k rpm turbo motor.
 

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Well that's a completely different turbo..

There are always those people out there who make great power with a less than stellar setup
There are always those dyno shops who set up their calibrations with a great deal of optimism. Maybe by accident, maybe to prop up the appearance of their tuning ability.
 
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