My RB30 Precision 6262 dyno

[ST240]

I've already established that my turbo setup isn't ideal, but I decided to dyno it on a whim (at exactly 12pm today) before the snow flies. HP Solutions got me in for 3:30pm. Awesome.

RB30 stock bottom end
R32 RB25DE head
Precision 6262 .58 T4
Nistune'd by myself



This thing is running PIG rich; when I got in there it wouldnt even register on the sniffer (<10:1). I should have tuned that out beforehand. I pulled some fuel and it went from 350 to 370 HP and it still didnt even register on the sniffer. With more fuel pull/timing add 400 rwhp is certainly possible. Not bad for the JB 6262. I'm impressed. The only downside is the .58 rear is choking it above 5800. Operator let off at 6500.

[DJ]

need a proper turbo on there hint hint BW 83-75

[MKIV]

Nice numbers , any goals?

[r33_gtst]

That torque comes in nice and early
Your right, then.58 is hurting you
That rb30/25 set up should easily do 500 rwhp and some good torque
I know the rb30 doesn't like to rev as high but with good gaskets and good tuning 7500 rpm Is ideal.
Keep us posted. An RB30 built bottom end /25 head is my next step

[ST240]

7500 rpm on a built motor fine, but on a mostly stock bottom end? I put arp rod bolts in for a safety net, but revving over 6500 with stock pistons and rods is a big no no if you dont want to risk scattering the bottom end.

I just got my hands on an rb26 head so Ill be putting that on there, should help a fair amount. And I'm also thinking of trying a borg warner s300sx 83-75 for a better match. I would really like to try swapping out the housing on this turbo tho too.

I want 11s in the quarter, thats my goal lol. I think with a good launch I'd be close, but i think you need a bit more than 400whp for 11s.

[r33_gtst]

GTR- 8k rpm
Built- 8k+ rpm

I run my Rb25 to 7500 rpm with stock motor, gaskets.
You can do 7k easy on that motor, I know the rb30 doesn't like to rev as high but it's still capable or 7k
With that torque you will get in the 11's with a good launch and bigger turbo

[cschepp]

Just remember man you have a rb30 bottom end. They came out of a diesel vehicle and they are very strong and will easily and I mean easily take 500whp. I would worry about making she the head flows properly, make sure you fuel is sufficient, I would get a different turbo(gt35, or a gt40), and lastly make sure your trans will hold all that power! Rb trans have a tendency of having the first and 3rd synchro go to **** because of a hard launch or simply missing a shift.

[DJ]

nowdays there are better alternatives to a gt35 and gt40 .

[cschepp]

You get what I mean... That size of turbo would be better. He will receive a more mid range turbo that could used to do many things. The turbo he has now will limit him to a low end get up and go and limit the power that is able to be made

[Speeddm]

First off don't waist your time the 26 head. the 25DE head flows so close to the 26 unless your in the 1000hp range don't bother.
Second RB30 was never a oil burner. Your thinking of the RD28.
Third run that thing! Let Neil tune it the stock 30 will put up with nearly everything but detonation.

I have many mate in NZ that run this combo in their cars and make 500whp+ on stock 30/25de combos and run the $hit drifting and driving daily.

[Black BNR32]

Just remember man you have a rb30 bottom end. They came out of a diesel vehicle and they are very strong and will easily and I mean easily take 500whp. I would worry about making she the head flows properly, make sure you fuel is sufficient, I would get a different turbo(gt35, or a gt40), and lastly make sure your trans will hold all that power! Rb trans have a tendency of having the first and 3rd synchro go to **** because of a hard launch or simply missing a shift.

the 6262 is roughly the same size as a 35r. his turbo is great for his goals (the rear housing might be questionable). he's still increasing power at 5800 rpms.

rev her out a little and work on the tune. done.

[ST240]

Agree to disagree. I think the RB26 head is going to make a significant difference (people have attested to this), and if it doesn't, I'm fine with that. I originally wanted a front entry plenum to clean up the engine bay and so I dont have to shim my hood half a foot in the air. But the RB26 head with ITBs is cheaper. Go figure.

Also, a lot of the guys on SAU say if you're running close to stock bottom end, keep figures around 300 rwkw (400 whp) to be SAFE. That doesn't mean I won't try to push it .

[JDMotion]

niiiice

[MKIV]

Sounds good to me. Keep us updated when you do the 26 head

[Speeddm]

25 vs 26. sure give it shot. You are correct when comparing a 25det but the de head makes the diff. But hey its your money. Have fun with it, because the forums are always right.