I pluggeed in Tim Bentons maps..I have the exact same mods as his maps call for...Now I notice boost creep of about 4 psi after 6000RPM...

Just wonderring if the boost creep can be tuned out or not....

 

I'm pretty sure the only way to get rid of boost creep is with a ported wastegate or by adding backpressure (via silencers in your midpipe for example). This was a potential issue for me but my R1 is only creeping to 13 psi, so I'm confident I'm ok (but just barely). Dave at KDR ported my wastegate and I'm still experiencing creep, btw.

One thing I had considered: remove the midpipe and insert a smaller diameter piece of heat-resistant metal in with one of the gaskets. I hadn't decided whether to try between the dp and mp or between the mp and cb. It might be worth a shot, and costs next to nothing if you do the work yourself.

 

hmmn ive heard u can tune it out.....but i really dont know..drop dave a e-mail....

 

I have clipped turbine wheels and hand ported WG. Since going to the Blitz FMIC and Ray's SS resonated MD I can't get less than 12PSI boost. Have not had any boost creep in 4th but have
not tried it in 5th due to traffic restraints at the time. It probably will be a problem when it turns cold. I'm making some SS blocking
plates for my exhaust.

To tune boost creep out would most likely require more spark retard and richer fuel. This would really cause your mileage to drop. I would think this would not be the way to go!

 

Boost creep is hard to tune out and most likely will not work. Once you have this type of problem a really good boost controller will eliminate your problem with the creep. Good luck.

 

I had a boost creep problem after I pulled my last cat. Actually, it was a boost creep problem that quickly became a blown engine problem. I pegged a 16 psi boost guage and was running a stock ecu at the time. As you probably know, the stock ecu cuts fuel at 13 psi, which was not a good thing. I fixed the problem by.. well.. installing a new engine, adding a power FC to control everything, and porting/milling out the wastegate. Now I run .90/.80 bar with no boost creep at all. Be carefull with boost creep, it cost me a new engine! You should be able to get the wastegate milled/ported for less than 200, if it's out of the car. A lot cheaper than 2400 dollars plus labor on a new engine! Good luck! Oh.. a pop-off valve might not be a bad idea untill you get the wastegate ported, just in case!
-Quinn

 

I dont think I had Boost creep issues with Spyfish's maps...

Waiting for Goodfellas to post his maps....

How are they coming Rich?

Who do I port the wastegate? I mean where do I port it?

 

Oh yeah I forgot...

When I had my motor done at KD back in April I mentioned to Dave I had a midpipe I wanted to install.....

He gave me some restrictor pills(Holley Jets) that he said to use when I was going to add a midpipe....

Do you guys think these will help the boost creep?

 

I don't know if the new pills will make a difference. What is happening though, is that with the removal of the cats and the addition of a more free-flowing air intake system, the exaust gasses are exiting with much more velocity. Since the exhaust drives the turbos, this causes higher boost pressures. Unfortunatly, the stock wastegate is ment to handle the stock levels of boost. Think of the wastegate as a "Y" switch. You have one path that leads into the intercooler/intake manifold, and another that just goes off into the atmosphere. The stock path/hole to the atmosphere is too small for the extra pressure, so even though it is trying to dump the access pressure to the atmosphere, it is not enough. That gives you boost creep. That oriface that dumps to the atmosphere is what needs to be enlargend. You could always upgrade to a single turbo and buy a better wastegate. The only way I could see you getting boost creep is if the celenoid that acutates the pressure release in the wastegate was malfunctioning. Possible, but less likely. Hope this helps!
-Quinn

 

One definition of boost creep is that the boost continues to rise even thought the wastegate is fully open. No change to the control system can fix this -- the wastegate is already all the way open! I think this is what happens with the RX-7 and an open exhaust.

The only things you can do in this situation are:
- run less boost; creep seems to get sharply worse above a certain boost level in most cars, for example, run 11 and creep to 12 versus run 14 and creep to 18
- restrict the intake or exhaust (exhaust restrictor plate sounds like a good idea for this)
- port the wastegate, which means enlarge the hole and clearance the flapper door so it can open more, this helps but you can still get creep (I do)
- go single turbo!

-Max