rb20det rb25 turbo.

[90240sxca18]

so ive got a rb20det. with a rb25 turbo on it. no tune, stock injectors walboro 255 and smic and hks bov.. it runs like **** tho, very slow. sluggish. a guy who does tuning rode in it and said it was very very very rich... but that doesnt make since with it being the rb25 turbo. i was wondering if i was to put the rb20 turbo back on if it would run like a stock rb20 appose to being slow as balls.. i think a while ago pre tune it made 145 hp or something like that. then afer a tune it made 235hp. but its not tuned anymore. so discuss what you think it would turnout like with the stock turbo back on. thanks.

[nissandrftr88]

define NO tune....as in you have a Stock ecu,or your chip has been burned to stock setting???Either way tune or no tune 145hp is weak,I think there is something wrong with your car.My NA KA made 158whp stock,and i made 258whp with a RB20det with RB25 turbo @ 14lbs with a stock ecu.

[90240sxca18]

no tune as in stock ecu. it was tuned with a safc at 9psi. first pull made 145 but i was told it was in the wrong gear? then the actuall first pull mad 209. but it doesnt spin first, doesnt chirp into second. doesnt do any of that, just slow and sluggish, no responce. just slow over all. so you dont think going back to the rb20 turbo would make it run better (faster)

[nissandrftr88]

nope...rb25 turbo isn't that big of a difference

[Cameron]

hahaha cullen, brents motor has always had problems.

[90240sxca18]

yeah but theres no reason for it to be this slow. i mean with a tune with a safc itl make 250 hp.. but why wont it make the 215 stock?

[drifter92sx]

define NO tune....as in you have a Stock ecu,or your chip has been burned to stock setting???Either way tune or no tune 145hp is weak,I think there is something wrong with your car.My NA KA made 158whp stock,and i made 258whp with a RB20det with RB25 turbo @ 14lbs with a stock ecu.

when you dynoed at 258whp on a rb20 wit a rb25 turb. which injectors wer you runnin stock rb20 270cc or the 370cc rb25

[Cjmartz2k]

RB25 injectors won't fit in a RB20 rail. One's sidefeed, the other is top feed.

I think you do have a problem, and I hate to sound like a broken record, but check for a boost leak. Make a tester, don't just look.

Also, just so you understand how it works, if you put a mod on your car that flows more air, the MAF reads that and adjusts fuel according to the MAP, which in the case of the stock ECU, will pull out timing and dump fuel into it to keep it "safe". RB ecu's are tuned WAY rich from the factory the more air they flow. I had car on the dyno with a bolt on RB25 and a stock ecu. .7 bar was 285hp with a/f around 11.2:1, .9 bar was 255 hp with a/f's around 10:1.

Check for boost leaks.

[90240sxca18]

yeah, i thought of boost leak, the pervious owner of the car had the same issue, same setup, same side mount intercooler ect ect. i ran a compression test, numbers were good so its not the piston rings, i thought it was the o2 sensor because i think i remember the power and ground wire on the O2 sensor being spliced so the only wire connected was the signal wire. but i dont really remember correctly. my cold start was f***ed up also. if cold it would barely start, and have a jumpy idle between 100-700 rpm, i would have to floor it and it would slowly raise, seemed like it would slowly start to get fuel, then idle normal. i now have a new turbo setup, T3/T4 stock injectors, SAFC II and a new intake plenum and a fmic instead of a smic, and this is all hard piping except for the piping to turbo and piping to TB. i havent gotten it running yet but we shall see how it runs, also i got a new o2 sensor

[shawn_16]

still got the rb25 turbo?

[l0nestar]

still got the rb25 turbo?

Dunno - but I have one F/S, if you are interested. Email me.

[drifter92sx]

RB25 injectors won't fit in a RB20 rail. One's sidefeed, the other is top feed.

I think you do have a problem, and I hate to sound like a broken record, but check for a boost leak. Make a tester, don't just look.

Also, just so you understand how it works, if you put a mod on your car that flows more air, the MAF reads that and adjusts fuel according to the MAP, which in the case of the stock ECU, will pull out timing and dump fuel into it to keep it "safe". RB ecu's are tuned WAY rich from the factory the more air they flow. I had car on the dyno with a bolt on RB25 and a stock ecu. .7 bar was 285hp with a/f around 11.2:1, .9 bar was 255 hp with a/f's around 10:1.

Check for boost leaks.

tight you made that much power on the rb25 turbo now you have a rb25 for less money lol thanks for your write up cuz im bout to pick up a rb25 turbo and wanted to see wat kind of power people were making thanks bro

[Blackx919xMagic]

Quick Question; I'll go ahead and admit that it's a tad bit noob and has probably been answered before but I couldn't find it. Okay, now with that said: Do you HAVE to upgrade your injectors to run around 250bhp?

[Cjmartz2k]

On a 2o? 250 wheel hp, yes. 250 at the motor? Just barely no.

[drifter92sx]

after 250hp you should get bigger injectors like the rb26 injec. there like 444cc

[90240sxca18]

no ones helped lol, stil cannot figure out why it runs soo f***ing rich. my IACV was broken as well i think. today im putting the motor in with a t3/t4 and a fmic, and new exhaust. i dont wanna drive it with a bigger turbo, and stock injectors with no tune. so im towing it to get tuned, ill see what happens.