Pushing the stock fuel system(Redtop SR20)

[-weekendwarrior-]

I have a question I need an answer for and I cant find much searching it. I'm planning on upgrading my cams to the hks step 1 256 in & ex in the near future. Here is my current set up.(the stuff that matters)

sr20
stock injectors
stock tune
walbro 255
aem wideband
fmic
tubular exhaust mani
isis rs3360 .86 (stock boost) equal to a s15 turbo but journal bearing
full 3" turbo back

My question is if I continue to run stock boost can I install the cams and drive the car normally? how much will cams effect my a/f? I've seen people pushing the stock fuel system with boost and aftermarket turbos so cams shouldn't be an issue I take it? The car is my DD.

The cams are just a supporting mod for my future upgrades.
gt2871r .64
550's
rom tune

my final goal hp is 320-340 with good response and torque to match

I just want the cams in and out of the way so the rest is easy as cake. Once my other car sells I can drop the money for injectors and tune.

[badbob2121]

if the tech section wasn't still down i refer you to the gt2871 users thread... its awesome and has alot of great info..

i would look into the JWT S3 cams and tune. As well as 740cc injectors instead of the 550's

i would not run the cams on the factory ecu, nor would i run the that isis turbo with the factory fuel setup... buts its your car and your motor to risk.. not mine

[nujabe]

Your gona want a safc or a rom tune at least a bigger fuel pump to feed all that. Also depending on how worn your valve train is be careful. Even thow 256. Is a low duration cam your still beating on a old engine.

[slider2828]

256 step ones are nothing... with stock boost. Might not even feel that much difference....

256 plus more boost definitely means tune and larger injectors

[-weekendwarrior-]

Sorry I do have a walbro 255 i forgot to mention.

The isis wasn't by choice it came on the car running stock boost and ive never turned it up and dont plan on doing so because I don't trust it.

I looked into the s3's and I thought that the lift was too high for stock valvetrain 11.2mm vs 10.5mm I researched and everyone always said try not to go over 10.5 regardless of tomei says.

I'll check out the 2871r tech when it comes back up. I looked around on here and couldn't find much but I never really use this site much. being deployed for awhile really takes all that car knowledge and throws it down the drain.

So your saying that 256's are a waste of time? I read that if your shooting for less than 400 go 256 or stagger 256 and 264 step 1's. For over 400 go with 264 step 2's. I think I ran across a guy's thread on here running s3's, 2871r .64, honed stock mani, jwt ecu and made 400hp 330tq. Since the s3's are 260 duration I figured the 256's are right for me since my goal is to be in the 320-340hp range

[-weekendwarrior-]

Oh and I thought the 550's would cut it but if you say 740's you got it. More room for upgrades later on i guess. I just thought they would be over kill for my goals.

[fullthrottle]

Oh and I thought the 550's would cut it but if you say 740's you got it. More room for upgrades later on i guess. I just thought they would be over kill for my goals.

with a gt2871r and 740cc injectors are the perfect match. They can put you near 400whp which is perfect imo