FasterIsBetter

So I'm going to run my wastegate directly to my boost source on my car for about 1500 miles just to keep things safe during break in. My wastegate spring is a 20psi spring. My question is, what are the numbers I should be expecting? I was looking on the SRTForums and saw the SRT4s making around 380-400whp on pump gas. I was thinking I should be seeing similar numbers or maybe slightly higher as most of these guys were on the stock head and cams at the least and I'll be running cams and a ported head on my built engine.

07LSJ

iTrader: (5)

i have no idea, but free bump to get some answers

MP Cobalt

iTrader: (4)

Get it Dyno'd problem solved

FasterIsBetter

Spshhh, by the time dynos start being around here again, it'll be broken in!! Then I know I can hit close to 475-500, especially if I run meth.

ItalianJoe1

iTrader: (10)

Why do you care about break in power? You shouldn't be abusing the car during the break in. And once you're ready to push the car, you are gonna up the boost and hopefully get it tuned before beating on it. So in theory, you should never make whatever power it would make at that level.

But yeah, under 400 assuming no tune and 20 psi.

FasterIsBetter

I won't be abusing the car, but I'll atleast roll into it a few times. It will be mildly tuned for the 20psi.

busa4

average power gains are about 10hp per pound of boost. so you can figure 200hp over stock hp should give you an idea.

cmiller8006

iTrader: (3)

Not very much on a 256, I would say in the 350 whp range.

MP Cobalt

iTrader: (4)

you serious 350 on a 256et?

cmiller8006

iTrader: (3)

At just 20 psi? Absolutly, that turbo on a 2.1 is not going to make great power till 24 psi and up. Its like my turbo, once we went from 23 to 24-25 psi we picked up over 40 hp when it started to get in the efficiency range.

MP Cobalt

iTrader: (4)

so you think i should of went with a 252et instead of the 256et for my swap? off thread topic but something i'd like to know. I know someone who is running 26psi on his 256et with stock motor

cmiller8006

iTrader: (3)

PMed back, but no the 256 is a great turbo, just turn it up a bit. For instance my car with the 5857 made just 320 whp on 15 psi

EXsoccer1921

iTrader: (14)

why not just run a mbc and turn it down?? 20psi is way to much to start out with. hell even when mine was broke in i was still only driving around at 14psi

elecblue06

iTrader: (1)

exactly people don't seem to understand that driving around dd'ing for 450+ whp isn't a good idea lol my car is setup now for 10 psi for dding and 15 psi for some fun

EXsoccer1921

iTrader: (14)

hell even at the track launching without the 2step and not nls'ing i still trapped 112 @14psi

vahdyx

iTrader: (7)

Maybe I should go 252 on 20psi then. I don't want more than 400 lol

FasterIsBetter

I can't turn it down any lower with a mbc due to my 20psi wg spring. Now if I put the 7psi spring back in, I can crank it up to 15psi. Some people don't realize your lowest boost setting is whatever your wastegate spring is rated for.

EXsoccer1921

iTrader: (14)

yes, i do realize that. but why the hell are you running that spring is the question.

FasterIsBetter

It was easier for james to tune for higher boost pressures with the factory wastegate solenoid and its easier on the solenoid. Remember, I had the turbo on the stock engine.

FasterIsBetter

And I wasn't accusing you of not knowing that. I was just saying some people...no need to get mad...if I was saying that I would have said "apparently you don't know what a wastegate spring rating really means"

EXsoccer1921

iTrader: (14)

a spring that stiff though just isn't necessary unless you'll be either running sping only, 24/7. or running boost higher than any cobalt has seen. i'm on a 9lb spring and am still able to run 30psi efficiently. if we turn it up on this freshening of the engine we'll put a different spring in but thats just an example.

FasterIsBetter

Well, the way I see it is where its a built engine, if I ever do decide to really crank on it when I run E85/100, then I have that capability with the 20psi spring but I most likely will put the lower rated spring back in. It held 26psi just fine with the stock controller and that 20psi spring but I'm going to be running a mbc now so I can drop it back down to the 7psi spring. I ran it off of the stock boost controller for boost by gear purposes only but I should have just bought a mbc from the beginning and ran it inline with the stock wastegate solenoid. But of course, I was thinking out my ass and seeing it as somewhere along the line I had to get rid of the wastegate solenoid to run a manual boost controller as well.....

InfraRedline

iTrader: (4)

Just for reference. Paintballerr78's car on the 5557 on 20psi and E47 on 22* up top made 377whp on a dyno dynamics. That was on his winter timing table which was coservative for E47, but still more than 91 octane will take. Just some food for thought I guess lol

EXsoccer1921

iTrader: (14)

mine on 91@20psi made 443..

conerboner

iTrader: (4)

so is 24 the efficiency range for the non extendid tip s256?