Wide Open Throttle aka pedal to the metal

 

Hos,
As long as you set the boost to the recommended
boost setting of the upgrade chips, you're not
going to run lean. A reliaboost II or accuboost is
enough to keep boost spike at bay.

 

J,
Yeah i know what you mean regarding boost settings and chips. It's the spike due to cold weather that im keen on solving.

 

Hmmm......intersting:

http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

 

Hey Hos,
Don't F!!!!K around with chips of unknown quality.
Just not worth it. Go Vitesse or Guru.
I run a Reliaboost & now an Accuboost. No problem
with spiking. The good thing for you is if you set
your boost at night, in the day your boost will be
reduced a little due to higher ambient temperature.
So, no spike & no overboost.

 

J,
Man, can't you take a joke after all that has been covered here on rennlist regarding chips, you think im going for some unknown brand come one dude, notice that ad gives 350hp with JUST the chips (and it is one chip not two ) which was the reason for the link

Anyway, just drove around for a while on WOT and half throttle. On half throttle it judders a bit on 3rd and 4th gear (not full boost) and still get the overboost situation on full throttle...........

An EBC would rule this out right? im going to double check the vacuum lines once more tomorrow morning, though i doubt that is the cause.

 

After reading the title, I just have to ask: can you overboost at part throttle?

 

Dark: No, but the judder i get on part throttle isn't the same as the overboost protection i get on WOT.

BTW, if your wastegate vacuum line cuts/comes loose or if you remove it, you would get overboost on PT you'd be seeing 22+psi boost on full throttle, so ~14+ on partial throttle.(don't quote me or flame me on this one PLZ!)

Anyway, i JUST got the partial throttle judder tonite, last couple of nites ago things were fine, only WOT that was an issue. Thought that info could help out in searching for the problem.

 

OOps, someone alreay said it

 

I am suspecting a leaking wastegate vacuum line now

 

BUMP

 

Looks like i narrowed it down a bit:

-First few minutures of boosts, everything is fine (even in the warm morning)
-Few boosts later, the car jerks at WOT Full Boost (no partial throttle problems)
-DME Relay is hot (normal?)

Any ideas?

 

I am having a similar experience with my 951. Pretty much, what hosrom is saying is that he is not holding boost through his RPM range.

Hosrom, do you notice that the boost doesn't give as much of a punch after this cutoff?


SHAUN

 

mideastmafia: well, honestly i didn't quiet notice any loss of punch.

Boost builds nicely (~3,00rpm or so) and holds it to redline (well, untill 5,200+ when boost drops from WG and Turbo anyway).

But as i mentioned, first few full boosts is fine, but later on it 'cuts' a couple of time when boost starts building up and when holding it at ~4,000rpm, but holds the boost, it just cuts at times.

 

WOT = Wide Open Thottle.

When I had standard chips and a lyndsey Boost enhancer, when the cooler weather came in I would hit the overboost protection. The winter air is cooler and more dense so you generate more boost. I would back it off a half turn and it was fine. Though on really cold wet days at approx 4,000 rpm in 4th or 5th it would still trip occasionally. Could back it off further but once or twice a winter I could live with it.
When the overboost has triggered you only get about 1.4 bar max on the in car guage. Switching the ignition off and on will clear it.
Tony