Crappy spool with sr20 t25?
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Crappy spool with sr20 t25?
Whats goin on guys, i recently switched from my ebay t3 manifold with the braineack 50 trim, to a custom log mani with an sr20 t25. Just got the setup finished and my spool is garbage. 5 psi by 3200 in 5th, worse in 4th. The whole reason i changed my setup around was for better spool, but my spool is horrendous. I’ve checked for boost leaks, tightened the wastegate arm(wg moves back and forth freely and doesn’t open until 10psi of compressed shop-air), and for pre turbo leaks. Everything seems fine, what gives? I also have a tial bov that after the turbo install, sounds a little different and quieter. It’s open at idle because the spring is too light, but it shouldn’t be leaking under boost, and it didn’t in the boost leak test. What the hells goin on here?
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What's the turbine housing a/r on the t25 and the old t3?
Some t3's spool earlier than some t25's for various reasons. Not all t3's are the same. There's a huge variation in the series.
Some t3's spool earlier than some t25's for various reasons. Not all t3's are the same. There's a huge variation in the series.
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.48 on the ol t3, .64 on the t25 i believe. It just feels off. I’ve heard of people gettin almost instant spool with the t25s. But my transient response is garbage too..
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The only thing i can think of that might be causing it, is that i had to clearance my downpipe quite a bit in order to clear the shelf with my vband adapter. I had to hammer it at the elbow, could this really be a bottle neck? I ordered a slimmer adapter and am going to try and see if a pie cut downpipe gives me a little better spool.
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A .48 will make a small t3 spool pretty damn quick. Exhaust wheel and compressor wheel size and trim can make a difference in spool also but I bet most of it in this case is in the turbine housing a/r. You can look for a smaller one for the t25 if matters that much.
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I agree, but a smaller turbine AND compressor wheel with a .64 ar which is equal to the 48 on the t3 and spool is this much worse? Something is off here.
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Thread Starter
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From: Chicago
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Journal bearing sr20 t25 turbos are not really spool monsters. I've had one on my 1.8L nb2 miata and was not impressed with the spool, the gt2560r I later installed spooled better. The t25 was not horrible, but not great, considering the small size. This was on a begi cast manifold and 2.5" dp to 3" exhaust.
a 1.6l with weld els log and smashed Downpipe is not helping it spool all that great...
Still it should come alive around 3500rpm or so
a 1.6l with weld els log and smashed Downpipe is not helping it spool all that great...
Still it should come alive around 3500rpm or so
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