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Turbo wanted

L485 turbo

Member
Hi I want a gt28rs who can I trust to buy it from and I take it I can bolt it straight to the std manifold with a 3" downpipe ??? Costs????
Rob
 
from memory no one makes a direct fitment gt turbo for the std 21t manifold because of the recess in the flange on the manifold side, most people either make a adaptor for the manifold or skim the manifold to remove the recess. for a 3" downpipe you can either use a cossie downpipe and modifly it to fit your car or make a custom downpipe to fit either a V-band type turbine housing or a 5 stud turbine housing.

to buy the turbo i go to CR turbos and ive always had a good service from them and very helpful.
 
Hi I want a gt28rs who can I trust to buy it from and I take it I can bolt it straight to the std manifold with a 3" downpipe ??? Costs????
Rob

First off, most GT28rs's come with a T2/25 exhaust housing so you need to make sure its got a T3 housing. Second, You'll need to skim the 21T manifold to turbo flange, as its not flat and the GT is. and lastly you'll need to sort out a wastegate flange as you can't fit a cosworth style exhaust housing. Oh and you'll need an oil restrictor as the roller bearing turbo's don't like high oil pressure.
Hope this helps
Andy
 
Oh and you'll need an oil restrictor as the roller bearing turbo's don't like high oil pressure.
Hope this helps

oh yeah i found that out to my cost blow all the oil seals LOL ive be told that anything above 25 psi kill the seals and bearing (thats s**t) but if you get the restrictor then they are the way forward
 
So based on all that work !!! What will reduce spool up and increase torque with ease??
T34 with a 48 exhaust housing????
 
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So based on all that work !!! What will reduce spool up and increase torque with ease??
T34 with a 48 exhaust housing????

if you are goin to use the t34 with a .48 housing then i would use bosch 803's (dark greens) with that setup, yes over a std t3 21t you will get a lot more troque/bhp, and spool up will be in the 2800-3200 area
 
So based on all that work !!! What will reduce spool up and increase torque with ease??
T34 with a 48 exhaust housing????

With ease, keep the turbo you have, stick a cossie exhaust housing and 3" downpipe including removal of the restrictive join to the main exhaust system. see how you get on with that, I reckon the down pipe should be ?150ish and the exhaust housing could be anything from nothing up to ?60ish from ebay, but go for a .48 and not a .63. Next turbo up would be a cossie 4x4 T3 as its got a slightly larger compressor over the standard T3.

Andy
 
if you are goin to use the t34 with a .48 housing then i would use bosch 803's (dark greens) with that setup, yes over a std t3 21t you will get a lot more troque/bhp, and spool up will be in the 2800-3200 area

...but if you put 803's on it it WILL need a remap or you'll overfuel and bore-wash it. Don't bother with new injectors beyond 357's unless you want upwards of 240hp.

With ease, keep the turbo you have, stick a cossie exhaust housing and 3" downpipe including removal of the restrictive join to the main exhaust system. see how you get on with that, I reckon the down pipe should be ?150ish and the exhaust housing could be anything from nothing up to ?60ish from ebay, but go for a .48 and not a .63. Next turbo up would be a cossie 4x4 T3 as its got a slightly larger compressor over the standard T3.

Andy

Do this. Cossie housing, machined manifold face, bin off the 5-bolt WG and have a flange or V-Band off the cossie housing. .48 hotside gets you good spool, .55 is a good medium between spool and top end flow, .63 is a lag slag but great flow and wont choke at high rpm/WOT.
 
I've got a T3 from a Bentley (same as Dave's) with a "v-band" style joiner & free flowing elbow/downpipe & i have to say it's by far the quickest 21 i've owned.....I've also addded a front mount intercooler & boy, she comes on boost something rotten...........you don't need to do to much to make your 21 way better than nature intended........
I'm not sure what housing is on mine as i'm no expert, but what ever it is it chuffing works a treat...:beguiled:

View attachment 1912
 
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...but if you put 803's on it it WILL need a remap or you'll overfuel and bore-wash it. Don't bother with new injectors beyond 357's unless you want upwards of 240hp.



Do this. Cossie housing, machined manifold face, bin off the 5-bolt WG and have a flange or V-Band off the cossie housing. .48 hotside gets you good spool, .55 is a good medium between spool and top end flow, .63 is a lag slag but great flow and wont choke at high rpm/WOT.


Pffft, what do you know...... ;) :P
 
First off, most GT28rs's come with a T2/25 exhaust housing so you need to make sure its got a T3 housing. Second, You'll need to skim the 21T manifold to turbo flange, as its not flat and the GT is. and lastly you'll need to sort out a wastegate flange as you can't fit a cosworth style exhaust housing. Oh and you'll need an oil restrictor as the roller bearing turbo's don't like high oil pressure.
Hope this helps
Andy

GT28rs, roller bearing big t4 sized turbo, with t3 style flange
T28rs, roller bearing t25/t3 sized turbo, with t2/25 flange like used on skylines, pulsars etc.

I've got a T3 from a Bentley (same as Dave's) with a "v-band" style joiner & free flowing elbow/downpipe & i have to say it's by far the quickest 21 i've owned.....I've also addded a front mount intercooler & boy, she comes on boost something rotten...........you don't need to do to much to make your 21 way better than nature intended........
I'm not sure what housing is on mine as i'm no expert, but what ever it is it chuffing works a treat...:beguiled:

View attachment 1912

whats going on with that v band? get rid of that clamp n get a proper band put on ! bentley's a t3 50 trim compressor, .63 ex housing. here's its bigger brother ;)

i50.photobucket.com_albums_f339_nocturnaldevelopments_renault_2021_20turbo_IMG_0014.webp

the difference between std elbow and a cossie downpipe

i50.photobucket.com_albums_f339_nocturnaldevelopments_renault_2021_20turbo_DSC01470.webp

DSC01419.jpg


So based on all that work !!! What will reduce spool up and increase torque with ease??
T34 with a 48 exhaust housing????

reduce and increase compared to what? std? to reduce spool up you want a smaller turbine housing, which will affect top end. increasing torque would mean more boost.
 
Pffft, what do you know...... ;) :P

I know that if you don't curb that lip you'll be looking elsewhere for engine parts! ;o)

---------- Post added at 10:04 AM ---------- Previous post was at 08:31 AM ----------

Mine- similar to the above but bigger. .48 back with the WG sealed, and an external WG before the Turbo. 3" mandrel bent exhaust all the way to the back.

Goes like hell.

i17.photobucket.com_albums_b79_DaveL485_quaddie_Photo_0131Small.webp

i17.photobucket.com_albums_b79_DaveL485_quaddie_Photo_0011_1.webp
 
Well seeing as everyone is showing there pipes lol........
View attachment 1913
one of the best things you can do and like Dave said with a decent front mount you'll notice a big difference! I did anyway :smile:
 
Eh? What's bigger?

Your Downpipe looked like 2.5"....I might be wrong though?

---------- Post added at 11:59 AM ---------- Previous post was at 11:58 AM ----------

....maybe it's 3" then, the heatshield makes the std pipe look bigger than it is....
 
Haz does yours exit the exhaust housing at 2.5" then go into 3"?? and what turbo is that is it one of the chinese t04E jobbies?
 
It's 3in cossie, just that the turbo's bigger. Yeah thats right dan, more pics in that album, link in 'the white one' thread. It's a copy but a bit of a hybrid now, cossie housing nor the Bentley fits over the turbine wheel so had to go external gate.

It's 2.5" off the turbo, as that's the size of the wheel outlet and a 3" pipe doesn't fit between the bolt holes hence the conical piece, actually it's less restrictive than the cossie housing.
 
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