boost creep at higher rpms

We may earn a small commission from affiliate links and paid advertisements. Terms

for right now i'm fine with this cast manifold


You're complaining about boost creep at high RPM's. That manifold design CAN CAUSE BOOST CREEP AT HIGH RPM'S.

If you're fine with the manifold, you should pretty much just get used to boost creep.
 
You're complaining about boost creep at high RPM's. That manifold design CAN CAUSE BOOST CREEP AT HIGH RPM'S.

If you're fine with the manifold, you should pretty much just get used to boost creep.

ahh, i wasn't aware of that. so, i should get a 3 bar map so my ecu doesn't cut when it does this? i mean, the needle sits right at like 9.75psi, almost 10. so if it creeps at all then it will cut, which is why i think its not much of a creep. also, the map sensor is pretty much maxed out at ~11psi anyway, so i assume i'll just get one and throw it one right before my tuner gets me setup. i'm only looking for around 300whp on 93 octane after i do my vitaras. should i be getting a new manifold for that power? maybe a log or mini ram from go-autoworks or an equivilent vendor and the appropriate downpipe and wastegate dump?
 
Last edited:
You can get a new map and have the car re-tuned, but sooner or later you're going to want a new manifold for a completely solid setup
 
Yup, what that guy said.

You can do everything else under the sun, but the bottom line is you have a manifold that is very likely to cause boost creep. Wastegate placement is key.
 
the boost creep/spike i can live with, as long as it only goes up 1psi or so after i put the new map sensor on, then thats fine. i just don't want it to creep up 3-5psi and boom goes the single cam!! yeah i eventually will get a new manifold setup but for right now, this is what i have to work with. and i know that the WG is placed on piston #1 runner and it needs to be in the middle of them all. i guess a 3bar map and tune will suffice for now and before i build my other block i planning on buying i'll get a mini ram and the rest to fix the problem. and as far as the "vaccuum lines that need to be checked for leaks", which ones would that be? thanks guys for all your input.
 
Last edited:
as far as the "vaccuum lines that need to be checked for leaks", which ones would that be? thanks guys for all your input.

Check the vacuum line running from the wastegate and the vacuum line running from the blowoff valve, mainly...and really, any other vacuum lines on the engine - there shouldn't be a whole hellova lot of 'em
 
yeah just go to an auto part store and get like 40 feet of vacuum line and replace everything

Are you fucking retarded?

:no:

First, there's nowhere NEAR 40 feet of vacuum line on his car...and if there's not a leak, there's no need to replace anything...and if there IS a leak, he only needs to replace/fix the hose that's leaking...
 
Check the vacuum line running from the wastegate and the vacuum line running from the blowoff valve, mainly...and really, any other vacuum lines on the engine - there shouldn't be a whole hellova lot of 'em

the vaccuum lines on the bov going to the intake manifold have zip ties along with the barbs holding them on, and the line going from the turbo to the wastegate has teflon on the fittings, and zip ties over where they connect to the boost controller and then to the wastegate. i do, however, have a plastic inline connector between the boost controller and the wastegate. im'a change that n see.
 
Currently you're running on a basemap?

I'll try to explain this quick and if you don't fully understand I'll elaborate.

Running on a basemap can be a huge factor in creep. If you're not running the proper ignition timing and fueling you can cause the turbo to spool more than it would when properly tuned by allowing unburned air/fuel to enter into the exhaust manifold and spool the turbo... Anti-lag during 2-step operates the same way... This effect will raise your boost pressure, pushing you farther to the right on the load breakpoints of your tune. A base tune is often rich to begin with, so if you're already rich at a low load, say 4psi, the more you go to the right the richer it becomes and the more your timing is retarded... and will cause your turbo to spool because of it...

Solution: Get it tuned properly and see how different your results may be.

I'm not saying the manifold design may not be part of the cause... but running around on a basemap can certainly be part of it as well. Good luck!
 
Oh damn, I missed that he's running a basemap...


good call, HRT
 
No biggy. Tuning is what my life has been based around for several years. I lookout for stuff like that at all times.
 
after thinking about this, im starting to wonder if a rich AFR could be the cause of creep on my setup and maybe it wasn't the wastegate..
 
yeah, my buddy's car is doing the same thing now, and the same person tuned the car
the thing is, my car was dyno'd and the afr's were consistent 11.0-11.5 ratios
my buddys car is just street tuned, but his ratios are close to the same and i don't see that being rich enough to cause that
 
That coupled with very conservative timing could very well do so. It's not just fuel, remember. If the ignition is retarded from where it should be it will not fully burn the air/fuel mixture.
 
wow guys that's a great point you made about being on a basemap with running rich and conservative timing. i been telling people that when the boost creeps that when i got it tuned it would fix that, but i was just saying that bc i wasn't sure why it was still doing that LOL. but i guess i could've been right haha. well i still have to check on the banjo fitting to see if its leaking. also i looked under my car and i was checking my ES inserts and the one that goes into the tranny torque mount broke the little zip ties things that hold it in. So, i have to try n figure out how to hold the other half of it back in there. i'm guessing i could put some window weld in there and press the other part into that or maybe try some zip ties with the metal teeth and some washers? i really wanna fill my upper mounts with window weld but im worried of the amount of vibration in the car, because its enough now to make your voice distort if u try to talk while i'm ripping on it.
 
That coupled with very conservative timing could very well do so. It's not just fuel, remember. If the ignition is retarded from where it should be it will not fully burn the air/fuel mixture.

you know what is funny is that the guy who tuned my car is very conservative. the timing was extremely conservative on my map. i think we barely started added any timing when we hit the dyno. maybe seven degrees or so. ive heard a good rule of thumb is 1 degree of timing per pound of boost. a good starting point at least.
 
Yup, that's a good starting point for most setups. Depending on the setup it could need a lot more timing from that point, though.
 
Back
Top