jaredcolletti

I got my rebuild in, 800 miles on it. full RB turbo back. running little to no boost (during the break in). ported the wastgate. wideband and vdo boost gauge, new silicone. walbro (this weekend installed and rewired). I reved the engine to 4k for the first 500 miles and 5k to the 1000 miles (?, i guess) what about after that.

when can I get silly with the car again?

BTW I bought a turboXs MBC to do this weekend and limit to like 11 lbs.

sound Ok?

jared

VetteKiller

if you car can make more than 11psi then the boost controller will not help limit it but you can set it to RAISE you to 11psi.

I'm in the same boat I have 800mi on mine and it hasn't seen boost or more than 4K rpm. Just be paitient and wait till you got 2000mi. Also be sure that you don't go from nice and easy to hard and fast, you need to do it gradually so that it breaks in properly

jaredcolletti

thanks dude,

hey, how do I limit my boost to 11lbs and as long as I dont run lean. I watch my widebad an I look safe all the time. granted, i am never under heavy boost soo.. Is it safe to boost to like whatever (say 14lbs) as long as I am never running lean?

AND

do I ever start reving to 6k (with little to no boost)

thanks Vettekiller and all who give insight.. much appreciated


jared

adamlewis

If your car made 11psi without a boost controller, an aftermarket boost controller WILL NOT help you. Boost controllers can only raise boost.

One way to lower boost is to add a restriction in the intake or exhaust. Use the search button, its been done before.

As for being safe as long as your not showing lean...
Theres two things that can cause an engine to knock
1) Not enough fuel
2) Too hot of an intake charge. More PSI = More heat

So to answer your question, No. Its probably not safe to boost up to 14 psi with just a walbro.

eViLRotor

iTrader: (2)

The best way to limit boost is to get an external wastegate, with a set spring for the boost you want.

DaleClark

iTrader: (55)

Uh, yeah....not with a stock turbo. In theory, it *could* be done with a stock turbo, but you're talking some serious fabrication effort.

On topic, engine break-in is 1000 miles. It will continue to get stronger after this point, but at 1000 miles you can consider the motor broken in and go beat on it.

Adam's dead on - best have your fuel in check. Stay below 10psi on the stock IC, and 12 psi on the stock turbo - my general rules of thumb.

Take your time, be careful, and don't get hasty and you'll be fine.

I also recommend an oil/filter change at 1000 miles as well. I typically run an engine for about 15 minutes, change oil and filter, then again at 500 and 1000 miles, then start regular maintenance.

Dale

rico05

Port the stock wastegate. That will help keep boost down.

adamlewis

No...itll stop boost creep/spike.

It wont lower boost.




Now if hes creeping to 14, thats a different story.

DaleClark

iTrader: (55)

Ok, it will stop boost creep, but won't lower boost...yeah...

What's boost creep? Too much boost. What does stopping boost creep do? Lower boost.

Porting the wastegate, especially on the '89-91 turbos, helps out a LOT. It isn't the end-all, be-all, but it does a really good job.

Dale

adamlewis

Dale...Youre a moron and welcome to my ignore list.

Im ASSUMING that he was getting 11psi without creep. So porting the wastegate WOULDNT lower that 11psi.

Secondly, boost creep != too much boost you idiot. Boost creep is when the flow of exhaust gasses is too much for the wastegate to handle. It cant let out enough, so boost continues to rise.






And if anyone bothered to read his first post, you would see that he already ported his wastegate.

jaredcolletti

hey DCFC3S,

pardon my ignorance but how do you "keep the boost at 10 lbs with the stock IC and 12 lbs with the stock turbo"?

I must be missing something

thx

jared

adamlewis

Hes just saying to try to not go above those numbers. 10+psi on the stock turbo is getting pretty hot intake charges. After a while, the stock IC isnt going to be able to cool that charge very well and you run the risk of knock.

jaredcolletti

so I can start boosting to like XXlbs in like XX miles? ...(aprehensive cowl)

adamlewis

huh?

jaredcolletti

like x amount of boost and at x amount of miles. and/or when can i start to rev to like 6k.

adamlewis

Id say youd be good to go around 1-1.5k miles.

As for how much boost you can run...Well...Id get an AFC of somekind and tune yourself a little bit richer before you start getting to 10.

Ive seen, and heard of, many FC's that blow with ehxuast, intake, and just a walbro as their only means of fuel.

jaredcolletti

I do seem to run 1 LED rich on the wideband under moderate accelation. So, maybe if I keep it there with no mods or like the apexi unit i sould be "safe". we shall see. I might be able to do it this winter. I am broke.

adamlewis

Theres a big difference between moderate accel and WOT