Guys I was wanting to know if anybody could get me any info on the Garrett GT42R turbo kit. What I would specifically like to know is about how many horses would I be getting to the wheels with around 13 psi on a mild street ported engine with no cats, a 4 inch straight exhaust, a huge intercooler, an upgraded fuel system, a microtech lt-12s, and any other normal mod that I forgot to mention? I found an amazing deal on a GT42R, or else I was originally going with a Garrett T04R and having about 550 to the wheels with my setup with about 13 psi. If you have a GT42R and have info on the turbo or have a dyne sheet, that'd be great. Any and all help will be greatly appreciated....
-Erik

 

a to4r is pretty small for a 20b, the gt42r is just about perfect. there are numerous dyno maps and numbers floating around for gt42r 20bs, you should eb able to find one for that approximate setup pretty easy. I'd say the 42r is the most popular 20b turbo there is, and that many people cant all be wrong...

i did a quick search and found 403@8psi on a stock block, so im saying you should make at least high 500s on a ported motor at 13psi

pat

 

i belive garrett doesnt sell the T04R anymore because its "obsolete".... they replaced them with the GT series

i think your talkin about the T04Z by HKS... which is basically a garrett T04R but tweaked alittle by HKS

correct me if im wrong


btw... counting down till seventock9 erik jan :]


- artin (turBRO)

 

I have the GT42R and made well over 600rwhp on the 13B. Im sure you'd make 600rwhp on pump gas alone on the 20B.

 

umm....i could be wrong about the horses made with the gt42r, but i know for a fact with a t04r i can make about 550 to the wheels with the setup i'm running (ported engine and all other normal mods). with a gt42r i would expect a lot more. an hks t04r (which is made by garrett) is still made by both hks and garrett. i know that the gt42r is a good turbo for the 20b, but i also don't want crazy horsepower or anything. i was wondering if with a gt42r a person can drive the car around the city without any major problems. i'm gonna take my car to the track every once in a while, but it's mostly going to be my everyday driver car. i'm gonna mostly ride my bike, but whenever i drive a car my 20b fd is what i'm gonna be driving. can somebody with a gt42r please post something up....
-erik

 

and so i stand correct.... i think lol

 

I have one on a street ported 20b -but it's not in the car yet

 

HKS makes the T04R, not garrett

 

the to4r is a non bb to4z


And a gt42r would bea very fine turbo on the street and could give you some wicked numbers if you ever wanted.

 

all turbos made my hks are actually made by garrett. the "hks" t04r is just a garrett t04r with a big hks logo on it. garrett does make their very own "garrett" t04r as well though; it's not only hks who comes out with it. there is no difference between the turbos. as for the t04z being a t04r with ball bearings, that is correct. i'm almost one hundred percent going with the gt42r, but i had one last question before i go ahead with it: with an a/r of 1.34, wouldn't i have major turbo lag with only 13 to 14 pounds of boost? i realize that the 20b can spool turbos with high a/r ratios up like a knife going through butter, but can it also do that with a turbo that big with that high of an a/r ratio? thanks for all the help so far, and let me know if you have the answer to that....
-erik

 

I was suppose to have a dyno day yesterday. I have this setup, but no numbers yet. We might be able to get on next saturday now though, i'll let you know.
My kit is the first one from Sean @ A-Spec. I also have the 1.15 Exhaust A/R.
Keep an eye out.

 

thanks dude. i wish my gt42r had a 1.15 a/r. that a/r ratio is perfect if you're not boosting too much on a 20b. an a/r of 1.34 is made for people who boost around 20 or more pounds. how many pounds are you looking to be pushing, and what are the specs on your motor and car?
-erik

 

By my calculations i should have:
~450rwhp running off the spring (8psi)
~650 @15psi
and it came to just over 800 @20psi
I dont have my sheet in front of me, but its something like that.

I dont know if i'll ever run 20 psi, since its just basically a street car/canyon carver (i live in Utah) but at a bar it should be loads of fun. Traction is going to be the big issue, i'm running 275's right now, but going to either 315's or 335's depending on what new wheels i go with. Its tough to find wheels I like in the right size without having to sell your left nut to afford them.
I"ll let you know what i put down.
Oh, and its ported wiht 13b housings.

 

wile im sitting here reading this. whats the advantage/ disadvantage (ive never head of it ) in running 13b housings in a 20b? i found somewere that sells 20b's with like 40-60,000 miles on them on ebay for around 3800, thought about buying one and sending it to the guys at a-spec for an overhaul and raceport and then throwing a pt76 turbo on it at around 18 psi. should be a fun car. i just need a shell to get it started.lol im not gona tear into my daily driver for that project

 

20b has very small exhaust ports compared to a 13b. they are literally like half the size, and the flow profile through them is terrible. it is possible to just swap the exhaust port inserts (i will be taking this route when i tear mine down), but most people opt to replace the whole housing. also i dont believe 20b housings are available new anymore, so if you trash one, 13b is your only option.

pat

 

so i should probably save my 13b rotor housings outa my old motor that have like 12k miles on them?

 

should i buy a complete 20b and swap housings. or just peace one together outa my 13 b and get some spare parts. like the 20b eshaft. im not sure if the irons are interchangable>?

 

oh one more thing i believe kiwi performance can get new housings for them, but they are in austraila and second. sorry for hijacking. looked like a good place for 20b questions lol

 

is it possible to make 1000whp with a gt42r on a 20b or would you need to go bigger

 

prolly with a big enough port and around 30 psi on c16 id assume so

 

has anyone used a gt47-80 or gt47-88

 

I have a Gt4788 on my 20b Bp. It goes real good! Full boost by 4500 rpm

 

what kinda numbers ? can it do 1000whp easy?

 

Should do it easy as.

 

when do you guys think my gt42r with a t6 flange will kick in with 13 psi on a street ported 20b with all other normal mods? i would like to know at around what rpm it'll start to work at and at around what rpm it will be fully pushing at. thanks a bunch for the info, and good luck with all your cars....
-erik