i was looking up compressor maps for my new setup, @18 psi everything looks great, but, @ 25psi it starts to look a little hairy, its right on the surge line.

here is what i have
sleeved 2.0
8.5:1 compression
extensive head work


anyone w/ something similar, boosting around 25 psi have any light to shed on this subject?

 

I wouldn't pay too much attention to compressor maps. I've never heard of anyone surging w/ the SC61. I have, however, seen a motor surge w/ the same compressor wheel though. It was a ball bearing Garrett GT3040R on an SR20. It surged as it hit full boost(full boost was 27psi) but then stopped and continued to make 550ish whp. I don't think you have anything to worry about w/ a slower spooling turbo and also a better flowing head.

 

thanks for the help, btw this is on a 3sgte if that changes anything

 

you sleeved a 3sgte? why?

 

stock bottom end is good for a little over 400, i plan on making more than that

 

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humm, yeh, for some reason I was thinking you have a Bseries vtec. I don't know anything about the 3sgte head, so i really can't compare it. but i've never seen an sc61 surge on a honda.

 

The SC61 can go into surge on an engine that small since the compressor wheel can push more air than the engine can swallow.

Are you running a T04E (3" inlet/2" outlet) or a T04S (4" inlet/2.5" outlet) compressor cover? You could switch over to a TO4S style ported shroud (compressor cover) which will solve that problem, but you need to be sure you have enough underhood & block clearance.

I'm going to be out of town at SEMA all next week, but call us at (219) 996-7832 if we can help with this. We're open M-F from 8-5 Central time.

Rod Short
Sales Manager
Precision Turbo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1.8LHatch &raquo;</TD></TR><TR><TD CLASS="quote">stock bottom end is good for a little over 400, i plan on making more than that </TD></TR></TABLE>

I've never heard of 3sgte sleeves cracking tho...

 

I would also suggest contacting Autolab (www.autolab.com). They are a local shop here in Louisville, but have done extensive mr2 work (3gste). Although the big block they built, see 2.3l stroker still had stock leaves, just overbored some. but custom intake manifold, custom exhaust manifold and a big GT series turbo. I think it was around 420+ before the boost got really crazy.

either way, i've never heard of anyone needing to sleeve that motor, but more power to you if you see yourself going past the limits of taht stock block. I believe the record for that motor is sitting around the 550-600whp mark.

 

well this is my race car, it only sees track time and some weekends. it should hold over 600 hp. the engine had high mileage before it was completely rebuilt