Hold On

Note: Not to stir the hornets nest or open up the Turbo vs SC debate again.

I am about to purchase a turbo for my 928 rear mount project. I have narrowed my choices down to two.

1983 4.7 L jetronic car. Stock other than Y pipe.

1. Garrett T4/T61 w/ GT35R compressor .70AR and P trim Turbine .68AR

2. Garrett T4/T67 w/T04R compressor .70AR and P trim turbine .68AR

as you can see they are speced out closely.

Question-- Is the T67 going to be too large for the 4.7 ?

I understand there are many variables that will be addressed after turbo choice. Feedback from those with working knowledge is appreciated. Thanks, Kevin

BC

What I know about rear mount is small. But what I have read is that the exhaust side needs to be smaller to capitalize on the reduced exhaust pressure, and the intake larger so that it can properly fill the extra piping.

PorKen

I'm contemplating installing a low boost mid-turbo in my '85 5-speed.


The more I look at it, a single universal kit from STS starts to make sense for a virgin boost noob like me. They size the turbo, and have most everything needed that I'd have to find, including the return oil pump.

http://www.ststurbo.com/universal_turbo_systems


I've started reverse engineering a 951 KLR boost box (very similar to an EZF), in hopes of using it for knock and boost control. For now, I'm installing a 951 tach with the boost gauge driven by the MAP output on the EZF (pin 21, 0-5v).

KLR, left, 2 bar MAP | EZF, lower right, 1 bar MAP

BC

Why don't you just do an in-box megasquirt?

PorKen

I like factory stuff. Plus it's a challenge.




For me, it's about the process, man... I'm not into dyno numbers, anymore.

BC

Challenge I get. Factory stuff - I've always thought the factory always improves something - why shouldn't I?

coast928

Porken, I like your idea of keeping it factory-looking and mid mounted w/ the 951 tach/boost gauge. If you ever figure it out pls. make a kit available. Thanks in advance.


Joel
'86.5 US A/T

Imo000

Yes but can't you run it leaner than a manifold mount turbo? With a rear/mid mount you don't have to worry about running it too lean and melting the turbine and it's a hell of a lot cheaper than a TT setup.

UncleMaz

+1

Iwanna928

They, STS have a neat site. I have looked and wanted one for a few years. I originally wanted to compound boost my Thunderbird SC. Rear turbo to help the M90 when she was out of gas in the higher rpm's. Run it w/ a blow thru MAF.

If you are going rear w/ a 928, might as well go to the experts. The only rear turbo that I have been able to find searching on the forum that had success started as a STS Universal kit. It seems that others have tried but ran into trouble and they seem like some smart dudes.

Another reason why I feel this is that they have all that experience figuring out the proper turbo size for a rear mount senario. Getting the proper size would be critical or it wouldn't run properly, or at least it looks that way to me. Imagine buying a turbo that was to small or to large and after spending all that $ it sucked!

Kit is also lower(1700) now compared to it's old price. Turbo, wastegate, oil system and possibly a couple misc pieces that you might be able to use. Doesn't seem like a bad deal.

I think it would sound AWESOME!

Stephen

PorKen

If I figure out the KLR programming, I'll make that available. A whole kit? Not so much. I don't to get 'Keeled'.

There's a virtual cathedral space on a 5-speed where the torque converter housing would be, not sure if you could do a mid-turbo on an auto.

porsche 928 RI

i think i saw an AT S4 with the turbo mounted right where the muffler whould have been, i wish sombody made basic kit, it would really be the most cost effective form of forced induction

Iwanna928

Porsche 928 RI Hey , check out a rear mount thread, there is a S4 that is making like 600hp w/ a rear mounted turbo!

By the way, I went to URI and sent a lot of time in Rhody. Great state, great friends there. Have a friend named Charlie Osborn that lives in East Greenwich. Big tennis guy w/ Wilson. Know him?

Stephen

Fabio421

What are your HP goals? Will you be running an intercooler? Do you hap maps for the T67 you want to use? I'm busy and don't have time to search for one right now.

Hold On

15 replys and not one answer. lol I don`t need a kit, I`ve already decided on rear mount, and it sure don`t take long on RN to get a post hijacked. Guess I will just call Mark and ask him.