Jump to content
SAU Community

Help I Need Suggestions


Recommended Posts

Coming home from work the M35 seemed sluggish and the boost gauge was reluctant to go to full boost. Theres no smoke being blown and no noises and when free revved the gauge only goes to its middle position, the engine is completely standard, ideas please.

Link to comment
Share on other sites

boost leak or wastegate stuck open?

get your head under the bonnet and check all inlet hoses for splits in hoses etc

have you done any thing to it lately, happened suddenly, getting worse?

Link to comment
Share on other sites

Dont know if this is relevant, but my c34 does that on occasion, boost it normally runs is 11psi but sometimes it wont go past 7, turn it off wait a few minutes and its back to normal, I believe in an older thread you guys said this was something to do with the fact that stags run 7psi out of the factory and a computer hicup can cause it to limit itself to factory boost temporarily or something along those lines? So if your running an aftermarket boost controller that may be why.

Link to comment
Share on other sites

boost leak or wastegate stuck open?

get your head under the bonnet and check all inlet hoses for splits in hoses etc

have you done any thing to it lately, happened suddenly, getting worse?

Daniel will have a good look tomorrow problem being can,t see damn all around the v donks. Car seemed ok this morning it was when I was going to give a mitsoshitty lancer a seeing to that I realised lack of go, so yes happen suddenly.

Link to comment
Share on other sites

Dont know if this is relevant, but my c34 does that on occasion, boost it normally runs is 11psi but sometimes it wont go past 7, turn it off wait a few minutes and its back to normal, I believe in an older thread you guys said this was something to do with the fact that stags run 7psi out of the factory and a computer hicup can cause it to limit itself to factory boost temporarily or something along those lines? So if your running an aftermarket boost controller that may be why.

Chris car runs factory boost so I,ll try again in the morning to see if it was a computer glitch if not back to head scratching or trip to Gold Coast to see specialist.

Link to comment
Share on other sites

Gerry, have you ran a check for error codes yet?

The system may know what is wrong and give you an indication of where to look.

Worth a check before you take it to a specialist, could be something easily repairable by yourself or a small time mechanic.

Good luck.

Link to comment
Share on other sites

Thanks everybody for your suggestions to my loss of performance but checked everything this morning and all looked ok so took it for a test run and it seems fine so we,ll see, shame really as it would have been a good excuse to get some more horsepower.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share



  • Similar Content

  • Latest Posts

    • I am impressed with all this level of adjustment. I didn't expect all this possibility
    • Correct.  In the case of the 500kw dyno plot I showed you the car actually runs two boost control solenoids for boost control and a 5psi wastegate spring.  It allows me to control how much boost pressure is applied to both sides of the wastegate valve at any point and fairly accurately control boost target as a result. I've tuned it so that it's able to target anywhere from 5psi to 25psi depending on what's needed.  The target tables I've set up in that car are Gear vs RPM, so every gear has potential for a different boost (and torque) curve.   First and second gear have quite low boost targets, third gear actually has different target boost all the way through the rpm range as it's a stock RB25 gearbox - the boost targets have been chosen to maintain a peak of 600nm (what the owner has set as the maximum torque he's happy with putting through the stock 3rd gear) but it carries that to the rev limiter.   The boost curve to achieve that is something of a ramp up, then hold, then ramp up again and the power curve looks more like a flat line haha.  
    • so you can decrease or increase the boost depending on the diet as you wish?     by acting on the wastegate?
    • That's torque and power, it's all from a single run.  The boost curve is "held back" from it's peak target in the 3500rpm to 5000rpm range from memory, so it ramps hard to something like 18psi then climbs more progressively to 23psi nearer 5000rpm.   It makes the torque (and power) ramp more "natural" and less hard on parts and traction, it doesn't feel artificially held back.   
    • Here's the torque curves from the car I ramped boost up later in the rpm to allow a slightly wider useful power curve - the power curve is a bit weird shaped also thanks to the TVIS (or whatever they call it with the 4EFTE in this Starlet) which changes the volume of the intake manifold throughout the rpm range, but you can see that the green power curve actually holds later on with the extra boost... but looks almost more like the kind of thing you'd expect from a cam or exhaust change
×
×
  • Create New...