[Supras] 57 trim CT@ boost capability

[berniek at technicaldevelop.com]

Brian and group:


    Just took a break from making up hard pipes from 2-1/4" thinwall 
steel tubing.  The Treadstone Spearco knockoff is due tomorrow.  
Although I enlarged the stock air box opening, the IC discharge hardpipe 
won't fit there due to the width of the HKS filter on the snout of the 
Lex AFM and the filler neck for the windshield washer.  Yes, the HKS 
lets a lot of dirt though, so it will be changed to something else, 
probably with 3" dryer vent hose to an element located below the 
headlight. I'll put a grille of some sort in the bottom cover there.   
No floods to worry about here.  In the meantime, I'm very careful where 
I drive. 


    I'm using the stock routing for the IC discharge pipe with a 
coupling hose where it emerges from the fender well (have my BOV in a 
2", actually 2.4", copper tee there for connection to it). 


    The car in question is a '91 with 550cc, Lex, 57 trim CT26, 3" turbo 
back and everything that goes with it.  Had a stock '90 before, only 
moving the wastegate actuator diaphragm connection to the 3000 pipe.  On 
cool days I noticed almost no boost difference (plenum boost transducer 
only operates dash gauge, nothing more).  On 80F days, there was 2.5-3 
PSI more (actually 3 PSI occurred when near 100F) with everything 
stock.  Nonetheless, I'm now running 15 PSI at the intake plenum, so the 
upgraded intercooler and piping are a safety measure.


    NAPA carries very good worm clamps with Belleville washers and 
radiator hose over 2-1/4" ID.  Wall strength seems more flexible than 
the Supra hose, however.  I may try some. 


    Bernie

Walker, Brian (Rich. Dist) wrote:
>
> Bernie, you're still using stock IC and pipes right? If you're seeing 
> 15-17 psi at the manifold, you're already beyond 18 psi at the turbo. 
> Replacing the pipes and IC with something more headloss efficient 
> generally frees up 3 or so psi so I'd bet you're actually producing 
> 18-20 at the turbo now.
>
> Not sure why you you didn't see a difference when switching the WG 
> signal (psi) location. Seems if you moved it to the manifold, there 
> would be 3 or so psi you wouldn't be accounting for (assuming a manual 
> controller) and you'd see the normal max pressure plus any headloss 
> you are now bypassing.
>
> Brian
>
> Date: Mon, 24 Dec 2007 19:59:08 -0500
> From: "berniek at technicaldevelop.com" <berniek at technicaldevelop.com>
> Subject: [Supras] 57 trim CT@ boost capability
> To: "Supras at supras.com" <Supras at supras.com>
> Message-ID: <477055DC.4040005 at technicaldevelop.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> The fellow (Mario?) at Performance Techniques tells me that the 57 trim
> mod is good up to 17 PSI from a bearing wear standpoint.  I'm getting
> 15-17 PSI at the intake plenum so I'm over that at the turbo.  A
> Treadstone Spearco knockoff is going in later this week, as are 2-1/4"
> hardpipes, to get the turbo discharge pressure down.  I do know that
> moving the waste gate actuator connection from the turbo discharge to
> the 3000 pipe caused very little boost increase under all but hot summer
> conditions (then it was 2.5 PSI difference with an all stock engine).
>
>
> Anyone have experience with life of a 57 trim CT26 at probably 18 PSI
> boost at the turbo?  Already thinking about an upgrade.  TO-4?  Needs to
> fit Lipp elbow and stock exhaust manifold.
>
>
>     BernieK
>
>
>