ok, heres my setup. stock s4 13b-t motor and turbo. front mount with 2.5" piping. 2.5" downpipe and exhaust to the cat. 2.5" gutted cat to a 3" catback. rtek7 1.7, 550cc primaries, 750cc secondaries. im trying to find out what would be the max boost id be able to run without messing something up. im hoping to get around 10-12lbs. any help is appreciated. thanks

 

Yes, 10-12 PSI is fine. 12 PSI is about the efficiency limit of the stock turbo anyway.

 

but dont you think 12psi is a stretch? it sounds like its a little high for a stock turbo. i wanna keep it safe tho too.

 

As I said, 12 PSI is about the limit of how high you want to go. After that, compressor outlet temps skyrocket. Hell, even around 12 PSI they're getting a bit high but at 12 PSI you're still making power.

 

so basically around 10psi is where i wanna be for daily driving and the track here and there?

 

10 PSI is fine. You're leaving a little power behind by not going to 11-12, but that's fine.

 

well ill probably run 10 for now, but once i get some more money and dont gotta stress over breakin somethin ill probably bump it up. with that setup and the right tune what kinda numbers you think ill be putting down? havent got it ready to dyno it yet, but you got any ideas? i talked to a guy on here with almost the same setup and he showed me a dyno sheet of him puttin down around 260 to the wheels.

 

260 to the wheels isn't going to happen on a stock turbo at 10 PSI unless everything in the world lines up and the dyno is perfect.

Figure 230-240.

 

well thats good enough for me. jumpin from like 150 on the na motor. especially on my first turbo'd car. but thanks for the help.

 

im on stock primary and secondary injectors and still boostin 12 psi. you're not going to "break" anything unless of course you boost spike. i have almost the same mods as you minus the injectors, and rtek. I have a walboro FP, just make sure to keep an eye on your A/F meter.

 

you know how much power your puttin down right now?

 

another question, i got a custom made downpipe when i did my swap, and they didnt put an o2 bung or sensor on it. does the rtek need that need that to operate? because i havent put it or the injecors in yet. she runs good just getting terriblet gas mileage and it takes forever to get running in the morning, but if i put them both on, will it work without it? or should i wait?

 

The RTEK does not need a wideband to operate. Most people without fuel controllers have them for safety reasons.

 

if you do not have your narrowband O2 sensor installed, I recommend you put it back in.

 

Lets not forget the fact that at 12 psi your getting close to maxing out your injectors.

Thats just stupid.

I dont think 12 psi is stock boost pressure.

 

well from all these responses i think im just gonna stick with 10psi. which is what im running now with stock injectors currently in, but i dont ever boost it because of the potention of maxin out the injectors. ill just wait till i get my o2, 750s and rtek in before i start boostin.

 

very good way to think before just turning up the boost like everyone seems to do these days

 

yea true that, i dont wanna blow somethin up after this swap takin 5 months of my time. and only driving it 2. doesnt really seem worth it to me.

 

i got 250 rwhp on 7psi on stock turbo

 

Post the graph.

 

He has an RTek and 720CC secondaries.

 

yea, well, i still think im just gonna stick with 10. ill probably turn it up at the track just out of curiosity. but i think 10 is fine for a dd. but yea, if you got the dyno sheet i wanna see. then a quick question, i have the stock fuel pump, and i dont wanna put the injectors if thats gonna be a problem, if it is, im gonna go ahead and order one, ive heard from different people, yes and no. so anyone got a solid answer for me?

 

anyone?

 

When pushing the limits of a stock fuel pump or unkown age or origin, its much safer to have a pump you know will work.

But 10psi on the stock fuel pump should be fine, presuming it works the way it did when it left the factory 20 years ago.

 

alright cool. ill just run it how it is and not push it too hard all the time, until i can save the money to get one.