Turbo upgrade on RB25DET

[HotRB240]

Anyone know for sure what is required, parts and labor, to do a turbo upgrade on an RB25DET? The stock T28 just isn't quite enough anymore, and I wanna go up to Gt35R or T70. I was quoted a price of $1200 on GT42, but as someone on other forum told me, it isn't a bolt on turbo, so that price prob won't stand once he sees what he's working with. I'd love to hear some opinions, and input from people who are familiar with the RB engine. Thanks in advance

[dickie]

moved to RB section.

[Coolwhip]

For a turbo of that size you'll need the following:

Turbo - what ever you go with - $ Depends

Manifold - $200ebay - $2300 Fullrace

Oil Lines - ~$150

Custom Downpipe - $0 + materials for a DIY - ~$150

Custom Hotpipe - Same as downpipe $

Custom intake pipe - same as above but less $

Gaskets, bolts, and hardware etc. - ~$100

Now be awear this is to bolt one up to have it operate correctly. If you are looking to go to such a turbo you'll need the supporting mods such as:

InjectorsECUand all the other parts depending on the application / powerwise.

[Darius]

Coolwhip is right on the money. I'm looking to do the same this winter and my budget is up around $6-7k plus another $4k in suspension mods and wheels and tires to curb traction issues.

GOD IF YOU'RE LISTENING, I NEED A LARGE TAX RETURN THIS YEAR TO MAKE MY CAR GO FAST!

[streeteg]

haha yup... thats what god listens to.... tax refund prayers for a turbo upgrade...

I am in the midst of doing a turbo upgrade now, and with the proper combo of parts and doing it yourself you can make some good power for relatively cheap. Gt 42 is overkill if you are a stock block. At most a 30R which will give you a good powerband and ~400whp.

[HotRB240]

Thanks so much for your help Coolwhip! That was very informative! The guy at the shop I called seemed to think I wouldn't have to change the injectors. Now I'm wondering, because I'm really only trying to get in the high 300 to low 400 range, do I really need a turbo that large? And, since it is a T25/28 on it now(that is the stock one, right?) would I be better off going with a T70? What turbo could I use that you think would be the easiest upgrade to do, and still get me near 400hp? I really appreciate your help! The mechanics I talk to at the shops in my area don't seem to be too familiar with the RB engine, so I wanna make sure I know what is needed so I can get an idea on price. I only want to spend about $2,000 on this turbo upgrade. THANK YOU ALL!!!

[Coolwhip]

For the record, stock rb25 turbo is a t3 hotside t28 cold.

for 300-400hp go with a GT3071R.

Turbo = $1200 or whatever you get it for.

Use your factory exhuast manifold = Free + welding on a external wastegate flange.

Tial wastegate 38mm or larger = $ find one, they're everywhere

and the rest of the stuff listed above. However, you'll need to do injectors if your going up in that range. 550cc injectors will do you. With some sort of management to control it as well.

You'll be pushing that $2000 turbo upgrade in parts alone. If you want to do it with labor then go with a T3/T4oE or something of that nature which go for half the price of a GT series turbo.

To tell you the truth no easy way around the $ tag when someone is doing the work for you.

Good luck

[HotRB240]

That was far more helpful advice than I expected to receive. Now, to allay your fears, assuming that the price of at GT30 is cheaper than a GT42, I should be fine. The guy at the shop, when telling me what the charges would be, said $600 and some dollars for the GT42 turbo. Then with labor he quoted $1200 to do the job. Then, he said they send out to get tuned and that would be around $800. So, that is why I was thinking I could get it done for $2,000. I'm hoping that if they can get the GT42 for around $600, they can do near the same on the GT30. I'll print your responces to take along to the mechanic with me. Thank you, really.

[Coolwhip]

you could get a fake plastic GT42 for $600

T3/T4 non ball bearing turbos go for that much.

All GT series turbos range over ~$1100+Thats for the turbo "ALONE".

Might wanna have an itemized contract/invoice drawn up before you do anything further than the discussion process with your mechanic.

[HotRB240]

Thanks. I'm going to call him again on my lunch break before I carry this thread any further.

[HotRB240]

OK, not that it's worth driving to PA for, but I had him confirm the price on the turbo and he said a GT32 would be $800 if I need wastegate, and he assured me that it would be neither fake nor plastic. However, if I wanted a T3/T4 it would be Either $350 or $400 if wastegate needed. Since I am not sure of what exactly I want, he is calling someone more familiar with RB to see what I may want. I told him I wanna get around 400rwhp and don't want to have to change too many things. We'll see...

[Coolwhip]

the GT32 is "alright" many KA-T guys run it. about 400@19psi they say.

Its no GT30 or GT35R but it does the job. The price is alittle lower than what I have seen but sounds about right. AMS sells them for $950.

However, note that this turbo is to be on back order so unless they have one on the shelve

A Tial 38mm will go for $250. Larger wastegates will be more money of course.

You'll still need to modify the manifold to adapt a wastegate and run a dump pipe from there as well as a custom downpipe for any GT32.

Gaskets, bolts, pipping, flanges, and misc hardware do add up. You'll need fuel management with injectors to get anywhere close to 400whp.

[HotRB240]

OK, for anyone who may have been following this and is interested, here is the final word on what I am doing with my RB engined 240.

Air Flow Controller - $480Manifold - $500Injectors - $600T3/T4 turbo - $350 Final price tuned and out the door - $2600

Then he remembered Downpipe and said $200, so

$2800 for an RB25 that puts out 400hp

[HotRB240]

Coolwhip, do you think it's worth paying $2800 to go from the stock turbo that is in it to a T3/T4, or do you think I should just get a good tune on the current setup?????? It's currently bored to 2.7l with wiseco forged pistons in.

[l0nestar]

Do you already own the bored 25, and this shop is just installing the turbo upgrade? Just to make sure.. what exhaust manifold are you going with?

[Coolwhip]

I seriously doubt you can get a RB25 to 2.7L with just a bore. A stroked crank would be needed as well.

Well, its up to you man, you are paying someone to do all this so I guess the price is going to be up there. What "Air Flow Controller" is he going to use? Sounds like the WEAK SAFCII to me. As far as a $500 manifold what kind? You can just spend $100 for a flange and having someone weld it to the stock manifold and bolt up a T3/T4 and an external wastegate to it without a problem. No need to spend the extra money.

Injectors thats a toss in the air. Might wanna shop around who knows.

Turbo sounds like a good deal though.

All in all, you gotta pay to play but be sure that you have everything else upgraded to hold the power...clutch, tires, rear end, cooling, etc.

[NPux]

Which T3/T4 turbo are you going with?

[mrose7716]

im swapping turbos and some other stuff on my rb25. gt35r/cams/metal headgasket/arp headstuds/PFC

ill post a pic when its done.

should be good for around 430-480 whp. hoping for maybe 500 on a good day if im lucky?!?

rb's are made to take abuse, once u get around 600 mark though thats when ring lands go bye bye

[streeteg]

how has anyone not called BS yet.... a bored 2.7 RB25 with stock turbo? GT42s for 600 bucks?....I call a 15-16 yr old with a pipe dream.

on a positive note--- good info in the thread...

[silviasgp06]

i think someone is confusing ".2" over stock piston diameter for adding and extra 200cc's to the total combustion chamber volume.so his math would be stock rb25 is a 2.5L and that plus".2" = 2.7L . Pretty sure it doesnt work that way.

i remember thinking like this way back when

[Coolwhip]

how has anyone not called BS yet.... a bored 2.7 RB25 with stock turbo? GT42s for 600 bucks?....I call a 15-16 yr old with a pipe dream.

on a positive note--- good info in the thread...

I seriously doubt you can get a RB25 to 2.7L with just a bore. A stroked crank would be needed as well.

you could get a fake plastic GT42 for $600

Believe I saw it

[Mute]

So I'm doing another DVD with Drifting.com, this one will focus more on building a solid engine, upgrading the turbo, and upgrading some of the parts that transfer the power to the wheel. We're only shooting for 500hp but I have learned there is a lot to it for sure. I am looking for information regarding the clearances which i dont feel where completely addressed so far. If you take out the stock turbo and upgrade it with a larger one, can you still have it mounted in the same general location or are you going to have to mount it higher or lower? Do we have any companies who make headers for left hand drive S13s with RB swaps? Would it be a matter of adding a bend in the downpipe or adding another angle to it? I think some of the guys on this forum really know their $#!* and I would appreciate any technical information someone could give me. As a matter of fact, if you could email me at [email protected] I'd appreciate it. Credit will be given in the video for anyone who ends up being instrumental in helping make this DVD that much better. Ultimately I am looking to make it a bolt on style upgrade, but I am feeling like it will be mandatory to have some fabrication involved. Thanks at any rate.

[Coolwhip]

Well, lets see.

500whp turbo in the stock location? Not going to happen, and if that not that easy.

Since its a side mount manifold it places the turbo wedged between the manifold and the strut tower. A GT30R and similar sized turbos bolt on there without a problem. However, if you get crazy with large compressor housing covers you'll find clearance issues.

The only advertised LHD specific turbo/exhaust manifold made for the RB swapped in S-Chassis would be the Full-Race manifold which is a top mount. There you can bolt on any thing really.

The other would be the HKS Cast manifold. However, limited availability for this manifold causes the problem as well as you MUST use the R-chassis crossmember. And even there you run into clearance issues.

Exact clearances to point A to point B, I dont know.

Regardless of stock location or not, a turbo capable of 500whp will defenantly have a larger rear turbine housing requiring a elbow made to fit or downpipe (modifications).

[cdorhout]

I'm currently running a GT3076R on the stock exh. manifold in the stock location. I'm running a 3/8" spacer to clear the compressor housing from touching the exhaust manifold. There is plenty of room between the turbo and the shock tower.

I'm estimating that I'm running roughly 425 hp at the wheels right now. That's at only 22psi. I'm restricted by my stock headgasket and stock pistons/rods from turning up the boost.

With internals done, 500hp is VERY do-able with side mount / stock ex. manifold.

[Darius]

To add to cdorhout's comment, if you think the stock log manifold is being restrictive, you can have it extrude honed to flow better. The factory design is fundamentally sound, but there are definitely ways to smooth and enlarge the runners.

[Coolwhip]

Good stuff to know, Thanks

How do you like the 3076 compared to the 3071? Might go that route 425 is a nice number and since I'll have the bottom built shouldn't be a problem to push it alittle more, huh?

[cdorhout]

I'm completely happy with the GT3076 so far. We'll see how efficient it is at higher boost levels after internals, but so far so good. I may want a 35r once I get up to 28ish psi. But the compressor map looks good on it.

425 is a good number, but don't kid yourself. It won't be enough .I got beat by a f'n turboed Integra at the dragstrip so guess what... more boost! I'm not letting a damn four banger put me down!

[meet07]

What was done to the integra???

[Darius]

Its a turbo'd ITR motor and he said he had a 60 trim turbo. Didn't ask how much boost he was running though.

Oh yeah and Chad forgot to mention that the integra was a peg-leg too jk man. The teg had slicks on and was pushing the 11.99 limit.

[streeteg]

I miss my old honda..... so fast for so cheap.... but I wouldnt trade the sound/style/ less % chance of my car getting stolen for another