Turbo selection

Post Mon Apr 30, 2007 3:16 pm

Hi all,

I'm curretly looking for a turbo for my conversion.

Currently tyhe block has been o-ringed with low comp pistons (8:1) and head has been welded etc. (M20b25)

I'm aiming for 350bhp (apprx 1bar of boost)and was planning on using a H1C however can't find one in the Uk.

I have searched on ebay and foung the following turbos what are your opinions,

1)
http://cgi.ebay.co.uk/cosworth-rs-turbo ... dZViewItem

Bit worried that the turbine housing is too small?

2)
http://cgi.ebay.co.uk/Garrett-T4-TurboC ... dZViewItem

not sure if the turbo charger is too big

Also does any body know a good website for maps, ive done the calculations (pressure ratio etc) but would like addtional advice.

Many thanks

Post Mon Apr 30, 2007 7:03 pm

Post Mon Apr 30, 2007 7:15 pm

i believe the t34 with .48 housing is good for about 360bhp.not sure about the t4.

Post Mon Apr 30, 2007 7:40 pm

cheers fuzzy, what boost are you running?

Post Mon Apr 30, 2007 7:44 pm

you need a bigger hotside to get 350 HP dude

I can source an HX40 with 19cm housing if you want dude, and I've realised I still have to supply a quote on the manifold

I'll do both in the am and shoot them to ya dude

Post Mon Apr 30, 2007 7:45 pm

17 psi at the moment but my t34 is capable of 27psi and around the 360-370bhp.stage 2 with 360 bearing and cut back blades. .48 same as the one your looking at. the t34 with .63 housing is good for about 400bhp im told on cosworth 4 pots.. im sure the t4 is smaller than one of the holset types frequently used by the e30 6 pots.

Post Mon Apr 30, 2007 7:49 pm

T34 with 0.63 hotside is borderline for the required output, dont forget a 6 cyl has 2 more power pulses to drive the turbine with, so whever works for a 4 pot is 50% too small for a six pot( simplification but you get the gist...... )

H1C, HX35 or HX40
18-19cm housings,

A pukka hybrid as per Dimmy's Sport is a lot of coinage, a few squid short of a bag-o-sand !

XS-power turbos( or similar Ebay TAT ) are NOT worth the risk !

Post Mon Apr 30, 2007 8:13 pm

Cool, i was going to avoid xs like the plague.

Will a T4 be ok?

Or should i just by a H1c from he U.S, as i can't really afford 1K for the turbo(my project will never get finished.)

Post Mon Apr 30, 2007 8:16 pm

T4 is OK, but a very old design, the modern derv turbos are more efficient than anything else on the market.

Post Mon Apr 30, 2007 8:32 pm

I guess i'll, have to get a holset then.

Do you have any links for compressor maps for the holset range.

cheers dude

Post Mon Apr 30, 2007 11:00 pm

wich is the better turbo for an e30, hc1, hx35 or hx40??