Building my RB25DET

[Joshhankins5]

I'm currently building my block and head and need to order a new turbo in the next month or so. I was thinking of just going with a ball bearing 6262. How well do these build boost? I'm shooting for 600hp-700hp for now. What are some other good turbos for this power range?

[Mile High Silvia]

The precision turbos are great in my opinion! I've had a 6262,6265, and 6765. I like the 6765 ball bearing the most because of the overall top end power and faster transient spool on the highway. The 6262 spooled quickly which created a lot
Of wheel spin. The 6765 had a softer spool and nasty top end power which was better for traction and over-all speed. I'd say get the 6266 with a t3 housing for fast spool and you'll still have good top end power. I had the 6765 with t4 .96 3"vband. That was my favorite

[Mile High Silvia]

That was on a vr6 2.8liter engine by the way!

[Mile High Silvia]

edit: double post

[Joshhankins5]

Sweet Ill have to look into a 6266 more. I don't really have any experience with precision at all.

[gostrider]

op what mani are you using?

[Mile High Silvia]

Precisions are super sick! It's an American company too so you can't go wrong. Their vband manifolds are sick if you can get a manifold made. I beat the shit out of all the ones I had an they ran great.

[Croustibat]

Originally Posted by Mile High Silvia

Precisions are super sick! It's an American company too so you can't go wrong. Their vband manifolds are sick if you can get a manifold made. I beat the shit out of all the ones I had an they ran great. [...]

Why are you using a t28bb and stock mani on your sr20det then ?

[RB25GUY]

Vr6's are a whole other animal compared to the RB25 its got higher displacement, I'm sure the head design has better exhaust flow what I'm trying to get at 6266 unless you are doing head work like cams if its not a neo solid lifters valve springs and retainers since the with the stock hydralic lifters tend to float at higher rpms and don't really like higher lift cams. It will literally take forever to spool.


I suggest if its apart getting rid of the 25 rods and pistons the weakest point to the motor other then the crank collar oil pump gear failure issue... a aftermarket harmonic balancer, damper, whatever you want to call it, is a great part to keep longevity of the bottom end although its not needed. Head studs, good hg,ARP rod bolts and main cap bolts bearings, crank collar and heavier oil pump gear also try to have a shop weld you a bigger sump on the oil pan its all about keeping the bottom end lubricated.

I would say for that hp look into a gtx4088r will be a good match so long you have a good set of higher lift cams. The RB motor is not cheap at that HP. Everything listed above if you are lucky is about 7 grand probably even more, and im forgetting alot of little details.

[Joshhankins5]

Originally Posted by RB25GUY

Vr6's are a whole other animal compared to the RB25 its got higher displacement, I'm sure the head design has better exhaust flow what I'm trying to get at 6266 unless you are doing head work like cams if its not a neo solid lifters valve springs and retainers since the with the stock hydralic lifters tend to float at higher rpms and don't really like higher lift cams. It will literally take forever to spool.


I suggest if its apart getting rid of the 25 rods and pistons the weakest point to the motor other then the crank collar oil pump gear failure issue... a aftermarket harmonic balancer, damper, whatever you want to call it, is a great part to keep longevity of the bottom end although its not needed. Head studs, good hg,ARP rod bolts and main cap bolts bearings, crank collar and heavier oil pump gear also try to have a shop weld you a bigger sump on the oil pan its all about keeping the bottom end lubricated.

I would say for that hp look into a gtx4088r will be a good match so long you have a good set of higher lift cams. The RB motor is not cheap at that HP. Everything listed above if you are lucky is about 7 grand probably even more, and im forgetting alot of little details.

Yeah I've got it all planned out already minus the crank collar I didn't put it the build but I will add it. I'm replacing everything basically. The head alone is costing me 4k. Bottom end is 2k. ECU, top mount mani, and turbo will be roughly 4500. This isn't including all the cleaning and machining of the block and head which I don't know the cost of. Its a pretty expensive build but a lot cheaper since I'm doing almost all the labor. Ill check out the gtx4088r as well thanks for the advice.

[Mile High Silvia]

Vr6's are much different but the head design of the 12v isn't the best at all. The vr6 will still
Spool massive turbos without much issue. My 6765dbb hit full 26psi right at about 4k. On the highway it would roll right into boost because of the ball bearings.

The 6266 will get you 700hp no problem, there are plenty of people even at Colorado elevation making 700+ on them. If you want to eventually make more power then go with the 6466 or the 6766. Compressor housing Choices will help with spool but with that much power you should consider the "H" cover.

I'm running the t25 because I like the fast spool and it's just a 2.0liter sr20. I like being able to punch it and go rather than sit there and wait for boost to kick in and then blow the tires loose lol. I've switched my style over the years from slow spooling, hard hitting turbos to quick spool that digs in and goes off the line. If I had an rb or JZ I would do a big single
Because the motor is better suited for that kind of power but for now I'm happy with my t28 s15 turbo with a billet wheel. It hits hard and fast and works well for what my car is suited for