tafkamb2

Hey guys,
I just changed out my tired turbos for some not so tired turbos and I ported to waste gate first I did everything including taking that metal out so it can open more. My question is I have a DP and intake on the car with the stock cat and stock intercooler should I still be getting boost creep? One more thing how important is it to put the outside heatshield on the turbos there being a real pain so I don't feel like putting them on lol.
Last question I read somewhere that sense we only have on waste gate it really doesn't matter what boost controller you use, like you don't need a twin turbo boost controller is this true?

dgeesaman

iTrader: (7)

You should be fine with a single boost controller. A second one will give you adjustment of the precontrol. If your transition is smooth there is no need.

You should not see boost creep with any part of the stock exhaust installed. If you install a midpipe you may see creep, but the first priority in upgrades would be to 1) control your boost and 2) install the intercooler.

Dave

tafkamb2

Im pretty much trying to stay stock right now while I get my other engine built up. Im going to make a V mount when i get the other engine together. Another question just to make sure I heard the stock ecu is good for 12 psi is that true?

dgeesaman

iTrader: (7)

No, you'll be constantly bumping off fuel cut.

11psi is as far as I'd go.

dave

tafkamb2

Thanks I'll just leave it at the stock psi.

Silver7even

What exactly is boost creep? I would appreciate a definition, or some links. Is it a static condition, or does is increase with time, long term, or over a pull?? Thanks

tafkamb2

Boost creep is when your car gains extra psi of pressure while your boosting. Its really bad on our cars because when you change a couple of parts such as the intake and exhaust it lessens the restrictiveness of those parts so much that it allows the turbos to spool more and create more pressure, and sense they fuel cut off is at 12 psi its not hard to hit that.

Silver7even

Thanks, so it is a static condition, once the mods have been performed, right?

Mahjik

iTrader: (1)

Start here:
https://www.rx7club.com/3rd-gen-archives-73/boost-creep-control-26389/

Some more info here:
https://www.rx7club.com/showpost.php...6&postcount=22

dgeesaman

iTrader: (7)

What you're talking about is just overboosting. Install an adjustable boost controller of some kind and it will be fixed. A few mods can create overboost.

Boost creep is when no boost controller can control boost, and under heavy load there is no maximum boost level. It just keeps increasing until you lift. Boost creep is caused by exceeding the venting capability of the wastegate.

Dave

Silver7even

Thanks to Dave for the definition of creep. Here is a shot of my overboost situation, this is not creep, but overboost (right?). This boost reading of 90 equates to about 16.5lbs of relitive boost in Denver, 1 mile above sea level.

Two questions:

Is this 16.5lbs of boost equivalent to ~ 13.5lbs at sea level?

Will a spring and ball work as a mechanical boost controller?

Silver7even

one more WOT example