Hey i need help with the A/R Housing: 1.0, 1.12, 1.24, 1.40 on the GT55R turbo im going to be putting on my bridgeported 20B. Any Help would be great.

 

idk.. but i want to see that thing when its done!!!

 

Err.. Drag Car??? How much HP you looking for? If it's drag, go with a 1.24. 1.40 is crazy.

 

what engine management?

anyway, since it's a bridgey everything in me screams 1.40, but i suppose the part of me that says play it safe would recommend 1.24. i'm just not sure. i think something in the 1.3x-range (if it were available) would be just right.

 

The setup would be 20b Full Bridgeport cosmo 13b front iron guru race bolts s4 low compressed rotors fd exhaust ports microtech ltx12 or ltx16 w 5 bar map I want to get more info on the 16 since it just came out and want to know how people like it I'm planing on boosting 35psi I'm going to be running a ams1000 boost controller by the way it's going to be street drivin lol

 

you must have deep pockets.

 

That's going to be one laggy monster and pointless for street use.

now as a drag car.. BADASS!

i would run a 1.24 or a 1.32 if u can get one

 

if you insist on having such a huge turbo on the street, and have the money to support this setup, look into figuring out a sequential or compound setup. or maybe triple turbos. you will be disappointed in the spool time on this for a street car.

 

Confused! Did you mean Cosmo rear iron? If not why did you go through all the trouble to machine holes in a front Cosmo plate and not just use the 20b's?

 

oh. well, i didn't realize that. in that case, smaller will likely be better for your proposed street use. a small T6 is still pretty big.

 

I dunno about the 1.40, that Gt55 has a big turbine wheel..

I would think the GT4708 would be a better setup.

 

www.rotaryonline.com.au sells a 20B Race 12.7mm Stud Kit (13B Cosmo Front Plate) they also sell a regular 20B 12.7mm stud kit. The Race kit that needs the 13b cosmo front plate has alot more studs and looks like its more heavy duty for boost. The car is going to be drag but drivin on the streets.

 

why not just 3 gt35rs? you'll get all the power you want out of those, and not sacrifice spool time.

even better, 3 bw s256s, and you'll pay less.

 

just go with a GT47-88 and call it a day..

is it a 3/4 of a chassis car or what?

 

My friend from PR is using a GT55R with the 1.40 in his 20B street RX8, I believe he has a 91mm inducer if I am not mistaken. The car is aggressively ported (no bridge), it has semi-peripheral ports that are actuated by a solenoid so that they remain closed at idle and low RPM. I would like to add that it is automatic and therefore probably spools faster than a manual. 1st gear is about 2.26 if I am not mistaken. He is running a Ford Thunderbird Diff in the back. It put down 1100 at the wheels at 28psi which is crazy. This is on Q116. He drives it around all the time at about 14-16psi on pump gas with alcohol injection. I'd say if its on the street, manual with shorter gears and not as aggressively ported you should probably go with the 1.2X A/R.

Here is a couple videos at 14-16psi (street tune) one on the previous GT4788R (with the crowd of people) and one with the GT55R (burnout in parking lot)...the tranny is a 6speed Shifttronics and he shifts it from an OEM Auto RX-8 steering wheel through a PLC controller (he owns a company that does automation for facilities).

http://www.youtube.com/watch?v=rMXHh...eature=related

http://www.youtube.com/watch?v=x72CH3VPqW8


he switched to the GT55R from a GT4788R...and he says its night and day.

I'd say go for it.

Chris

 

There is no need to run a large A/r on this turbo, A/r is a function of turbine wheel size. This turbine wheel is 111mm run the 1.0 and be happy with it. I don't see any need to go with larger than a 1.12 unless this is serious drag car or for bragging rights.

~S~

 

THANK YOU ChrisRX8PR
that is a nice setup on the RX8 i was actually thinking about doing semi pp with solenoids to open on high rpm and close at low rpm almost like a 6port setup. Latley iv been having brain farts because of the the other things that iv been trying to do to the car.
Also i am going with a T56 6 speed transmission with Gforce gears and a cobra rear end.
Also with the intake manifold iv cut the upper in half and have taken all the crap from inside the manifold and am making a custom plate/spacer that is going to hold a Acufab mustang race Throttle body. I am not sure what size im going to go with a 90mm or 110mm.
For Inside the intake im going to send the upper half and LIM and get them honed out more for better flow. for injectors im going to be running 12 injectors.
Rite now iv stripped the whole car. I mean completely stripped the whole car the whole inside and outside is bare metal and prob in 2 weeks im going to make a home made rotisserie so that way im going to strip everything underneath and am going to seam weld everything then sandblast everything once i get the roll cage put in. Also for the back half iv taken the metal were the spare trunk was and am making a nice setup for my fuel cell out of sheet metal. its going to look compleatly stock with out the hump of the spare tire. i will have pictures soon

 

Sounds like a killer setup. My friend Robert went with the 110mm, said it was night and day compared to the 20B based one.

Good luck!...oh...and Zero-R makes a good point, with a big wheel the difference in flow between low and high A/R's isn't that huge compared to the overall flow, it will definitely make it more responsive if you go with a lower A/R.

Chris

 

Zero R = turbo god

 

Find out what the cost of the hot side and get a few if you can, I have never dealt with a turbo larger than a 80mm but a change in AR will change the feel of the car a lot so you may end up enjoying 1.0 or 1.12. I vote start in the middle with the 1.12 or 1.24. Get a CHEAP mechanical boost gauge and run it as a back pressure gauge, this and a EGT before the turbo will tell you so much about the setup. Then if you want more response go smaller, you want more boost go larger.
Me.... I like Chaotic's idea of 3 bw s256s, nice quick spool and good airflow. BW turbos are cheap, durable and LOUD!!!

 

3 turbos. I am pretty sure he was joking, that would be retarded.

Turbine housings are expensive, $399+ new

 

Im going to be boosting the turbo at 35 PSI so i need to figure out ether a 1.24 or 1.40 most likely i will need to go with the 1.40 since im going to be boosting at 35psi

 

My project is going to be like Gotham racing with the GT55R But since Things happend i think their project never got finished.
link
https://www.rx7club.com/showthread.p...ighlight=gt55r

 

The Axis car was tri-turbo...

 

I was joking, but that doesn't mean you couldn't do it.