Easier to upgrade turbo: RB25 or RB26? More Questions

[Turbo200sx]

Well, today I traded the t3/T04e I was running on my Ser to a buddy of mine for a T4 60-1, brand new so I guess I lucked out. I figure that the turbo is going to work good for me since I'm doing a RB series 240. I had planned to run the auto, but I think that I'm going to run with the manual transmission for now unless someone can convince me otherwise. I may have a deal on a friend's S13 Coupe, but we'll see.

Now, the turbo is pretty big. The reason I got it is because the guy that sold it to me thought it would be too big for his SR20 since he didn't plan on doing any internal mods. I figure the RB series would work a lot better with the bigger displacement and 2 extra cylinders. Am I correct in thinking this?

Also, can anyone suggest a manifold? I saw a nice one on Ebay similar to the SS Auto Chrome manifold, but the runners themselves were almost a full mm thicker and every runner was reinforced and braced. Looked nice, but I didn't know if anyone had any better manifolds. I'd like something that I wouldn't have to worry about breaking.

Second, Will I have a problem running the stock intake manifold with the upgraded turbo? I'm not exactly sure how the piping would run, so I was concerned about how the piping for the intercooler and such would run.

Third, Will the stock ECU + SAFC accomodate the turbo and fuel setup or do I need a PowerFC/JWT reflash? I plan on using the Walbro 255 that comes on the car, but I don't know the limits of the factory injectors and MAF sensor. I would like to run a significant amount of boost.

I think that is all the questions I have. I need to get a little more familiar with the RB setup before I actually start working on doing the swap, but we have our own shop so labor and time is nothing.

Any information would be helpful. Thanks guys

[Turbo200sx]

Oh and one thing I forgot to ask, which is mentioned in the title. Would it be any harder to upgrade to a single turbo on a RB26 considering it has a factory twin turbo setup as opposed to the single setup already on the Rb25?

[biglipzit]

does the T4 bolt onto the rb25 manifold without an upgrade mani? If it does then it will definantly be easier to put that turbo on a rb25 instead of having to buy a completely new manifold for the rb26 and since it is such a rare engine in america i can imagine paers are a bit more expensive.

[SeVa-S13]

That will not bolt onto any stock RB manifold.

[intrexin]

i think the question for you is how much money do you want to spend and how much power do you want? then figure out what turbo and motor combo you want/afford to achieve your goal. Like in my case i could afford the rb20 and only want a max of 300hp also my car was auto and now i have a 5spd.

[Turbo200sx]

Money isn't a problem really, the build will cost what it does. I just want some answer to the above questions. I'm already working with the T4 60-1 turbo, which has a T4 flange and I knew wouldn;t bolt up since the RB25 uses a T2 flange turbo.

[SeVa-S13]

Neg-- the RB20 and 25 both have T3 flanges stock, the 26 uses T25's.

And since money is no object, get one custom made for your application. That's always gunna be the best bet if you're got the cash.

[enginerd]

If you're planning on running a big turbo with high boost, I would definitely recommend something better than a SAFC. It could probably work, but since money isn't a problem, I would say go with the AEM EMS with the UEGO wide band option.

As far as going with a single turbo on an RB26, I'm pretty sure HKS and others make a single turbo manifold for around $1,500. I don't know how the placement works in an S chasis so the best bet for proper fitment would be a custom manifold.

You may want to look into upgrading the stock injectors too. The RB26 comes with 444cc injectors but it sound like you may want to look into 555cc or higher ones. It depends on what kind of power and boost you plan to run. You don't want to max out the injectors. If you're running an RB25, you'll probably want to upgrade the MAF.

[Turbo200sx]

Neg-- the RB20 and 25 both have T3 flanges stock, the 26 uses T25's.

And since money is no object, get one custom made for your application. That's always gunna be the best bet if you're got the cash.

The problem with getting one custom made is that I'm in Tn. For some reason, there isn't a damn person around here that can do any type of decent fabrication or welding for ****. At least in middle Tn anyways.

Are there companies that custom make turbo manifolds over the net?

[enginerd]

I'm sure there are plenty of places online that will make custom manifolds, but I would try to stick to someone who is familiar with the RB swap 240 to ensure you won't run into size issues. I don't know if McKinney Motorsports can make one, but I would definitely try asking them first.