My freind has an 88' S13 and says he ran a straight pipe with a stock ecu and stock wastegate (not ported). He also has an intake and a frontmount intercooler. Also another freind is running a straight pipe on his lancer evo 9 and an intake and an intercooler on a stock ECU. Are they just screwing with me or is boost creep a major issue only for rotaries? I cant see why it can only be for our cars but i want to know what you guys think
Thanks
-Daniel

 

boost creep happens on any turbo car where the boost is not being mechanically or electronically controlled.

if u have a SR20DET for example in a S13 with a full straight 3.5" exhust for example and the ECU is not tuned or there is somthing wrong with the wastegate.... you will get boost creep.... when theres not restriction basically.

 

When a properly sized wastegate opens, exhaust gases are diverted away from the turbocharger(s), and boost decreases. The ECU (or boost controller) is what opens the wastegate at the desired boost level. If other cars have a better sized wastegate, or a better control system, they won't have the same issues with boost creep.


It's also very possible that those engines don't flow nearly as well as the rotary, so wastegate control isn't nearly as much of an issue.


-s-

 

1) Yes, boost creep can happen on other engines.

2) Too much boost = going lean AFR = detonation. On a rotary, it blows your motor pretty much instantly. On a piston engine, it's a annoyance. So those that have some boost creep probably don't care much.

Dave

 

Absolutely correct! That's why we (Wankel-engined) are (or should be) very concerned about creep or spiking.

Dave W

 

Piston motors can pop (throw/bend a rod, fry rings, pit pistons) with detonation as well. How much detonation a piston motor can take depends on things like if you have forged internals, legth of the stroke/rod etc. It is not just an annoyance although yes a rotary will blow much easier than a piston motor with detonation and I am sure that is your point.