So after doing some reading and such, im still wondering, how big of an a/r can you go on a turbo and still manage to keep it streetable and keep the lag down and things like that.

The reason im asking is that, i plan to buy my turbo this month and this is the one im looking to get to run on my halfgridgeport

http://www.turbocalculator.com/view-...ct=002-001-012

The specs i choose are the following..

88mm,54 trim (0.72 a./r ) compressor housing
84trim ( 1.19 a/r ) turbine housing


so im wondering if that turbine housing is too big for my application

 

IMO, on a half-bridge, that turbo would be a great all-around turbo. On moderate boost, you will see about 475-500hp. lag should be minimal. Basically, it boils down to what you want. Do you want a crazy hp producing machine, or something that you can have fun in, given any situation.

Ty

 

thanks for your imput

anyone else?

or should i go smaller to a .94 a/r

 

I'm going with a .96 hotside on my full-bridge. Anything right around 1.00 should work great. I ran a 1.15 on the stock ports and it had some lag but nothing horrible. With a decent port it should be perfect.

 

anyone else?

 

here what you get from them...POS.big heavy bell cast and need a special 5 inch clamp. It a from a Scandia truck. Dont bother cutting it cause each cast is different and you may never get a weld to hold .Now your modifying that GT40. Just get one from somewhere else . I warn you from experience.

 

i have a pretty big one... its a t04s compressor side with a t04x2 a/r side which is about 1.15 i have a mild street port and i experience no lag(figurative speakin).... if i'm about 4k rpms...

so... i'm sayin go with the bigger one... u will not be disapointed... IMHO we(13b's) get very little lag. if in the right rpms....

 

Go with the LARGEST turbine wheel thats practical , this would keep the back pressure down , once this is under control you can use anything from a 1.0 , 1.15 or even a 1.22 a/r turbine and still get good response and power .Remember , the turbine wheel is the largest restriction in a turbine , it has a greate effect on back pressure which would adversely or positively affect a "big port" rotary , the a/r dictates the power band of the turbo / motor , once its over a certain size it has minimal effect on overall power. I have a friend who has a fully bridged motor with a TA45 / 51 on it , the a/r on it is 1.32 , he makes 515 RWHP @ 18psi , everytime he tries to raise the boost the power falls off ....... too much back pressure on the motor caused by the turbine wheel , the same one that had worked well (489rwhp) on his previous street ports .

 

Ok i changed my mind again

i actually think im going to buy this one

http://store.yahoo.com/cheapturbo/garrettt4to4r.html

with a 1.15A/R

i think it will flow nicely with my halfgridge port........any comments and i know which ever turbo i go with im still going to need 2 fuel pumps

 

they offer than same turbo with a bb chra. Its an addition $499.99, but if your going big you might be interested.

 

It won't be posted on their website so don't look for it...lol.

Call and talk to Ken. REAL knowledgeable guy.

I was looking at the same turbo in a T3 version.