will +20s work for me?

[UPSIDE-DOWN-FACE]

heres the setup im running-
2.5 T1 mitsu turbo
srt intercooler
3" side exit exaust
g-valve b/c & cutout raiser

from what ive read. the mitsu is good to 18-20psi right. well i dont plan on drag racing all the time. once or twice a season. this is mostly my daily driver. if i wanted to run 17 psi on my car, should i install +20s and a afpr? and what will my fuel pump hold to? is it difficult to run the 20s on a stock computer? thanks for any help.

kyle

[shelby zed]

you shouild run bigger injectors and a fpr, as well as a 255 lph walbro. but what ive heard is injectors will run +20 all the time, the computer doesnt change it, so since a 2.2 turbo computer runs 15-17% less fuel than a 2.5 comp you could use a 2.2 comp and + 20s to get an extra 3-5% more fuel, enough for 17-18 psi

[shelbyplaya]

your biggest gains will come from a better turbo

[UPSIDE-DOWN-FACE]

im well aware a garret would be better. but the mitsu on it is in perfect shape. and will be fine to run for my street driving. until it comes to that time to put a bigger turbo on. is there any negatives to running the 2.2 computer with +20s on a 2.5?

[shelby zed]

2.5 engine with 2.2 computer and 42 pph injectors.

Ahh the one special case! Mopar Performance sells a 42 pph injector- It flows exactly 20% more then a stock 33 pph injector used in the 2.5 engine. Now from what I understand the 2.5 is 11% larger in displacement then a 2.2 BUT it's fuel curve is 17% larger... so what does all this mean? If you install a Turbo II 2.2 computer on a 2.5 engine the calibration will be 17% lean... unless you install a the 20% larger 42 pph injectors at the same time! This is the setup I ran on my K-car and it works pretty well and the extra 3% of fuel will get you up to 16-17 psi. Some cars seem to need a little tweaking with the fuel pressure and others have no problem at all. This of course lets you swap a 2.5 into a car like a GLHS that never had a 2.5 computer available for the application from the factory... you get the idea..


copied from the dodge garage in adding fuel

[UPSIDE-DOWN-FACE]

would it be better to run a RRR or the 2.2 comp with the +20s?

[Speedeuphoria]

I would stay away from the RRR, if on a stock pump, pressure kills the pumps and RRR's can be hard to tune good. Anything can be done though, its up to you

[86Shelby]

Dial back your base timing to 6-8*. It will run fine with the +20s then. Been doing similar to that for over 3 years now.

[GLHSKEN]

8^ seems to be the timing my car likes TII computer 2.5L with +20's

[UPSIDE-DOWN-FACE]

so it sounds like i should go with the 20s and the t-2 comp. that set the timing to 8*? and that will give me enough fuel for 17psi?

[Stinkbox]

i have timing at 8, dsm 390cc/min which are same as plus 20's, garret t2 and stock comp and it runs great, bogs if your below like 2k and floor it but the extra fuel up top is so worth it. im also running 20 psi.

[TonaChris]

I have almost exactly the same set up as you only I have a 255 pump and FFV injectors. Which are around +15 to +20(forget exact amount). I run 17psi on it and it runs great. No tuning, just the stock 90 t1 cal and it doesnt seem to run too rich, the narrow band still bounces around at idle and cruise like its triming the fuel nicely.

[iTurbo]

Why would you want to run a 2.5L on a 2.2 cal? What kind of car do you have the setup you described in? If the 2.5L was stock, just continue to use the stock computer and install the +20s. The car will run fine, even with stock fuel pressure.

I have a similar setup in my Omni GLH Turbo. It's been converted to '89 electronics and uses a 2.5L TI SMEC, with +20 injectors. Driveability and MPG are unchanged from stock injectors. Plenty of fuel for 18 psi, on a stock engine with 3" exhaust and big NPR intercooler.

[Subliminal]

I run +20s and afpr with about 45 psi with the vac line unhooked on my 2.2 with a garrett.

The dawes is mostly green @ 17-18psi.