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No your right, boost should probably continue to climb up to 6500 or 7000 depending on your tune setting.
And that low at idle I'm thinking maybe boost leak as that is a good way to gauge that....maybe cracked line for the FPR from right side of horn ? My last boost leak I found to be missing metal gasket at left side supercharger horn....
Who did your tune ?
Bytetronik has some experience with modded R53's, Bytetronik maybe he can chime in.
Hi guys, I´m sorry for digging up my own thread again.
But i´m yet to solve this problem!
Today I installed a detroit tuned BPV, I gained about 0.5 PSI across the rev range but unfortunatly the problem continues.
I get Peak Boost (13.4PSI) at 5600RPM and then the boost goes down to 12.3 and stays there till the rev limiter.
I dont know where to find the missing boost, with a 17% pulley i should be pushing 16 PSI.
Any ideas where to turn to next?
Already did belt, tensioner, BPV, IC Boots.
Any help is apreciated
As you can see after 5600RPM where I hit 13.5PSI the it drops to 12.4 and stays about there till the end
I still think your Newman cam might have something to do with this.. My catcam sees boost rising up to about 5k rpm or so and then kind of pegs there all the way to redline without further increasing, although power is still climbing. I just think its a bit of overlap hence our boost doesn't continue to build to redline like an engine with a stock cam.. Would be nice if other Newman cammed owners could chime in with their logs
I still think your Newman cam might have something to do with this.. My catcam sees boost rising up to about 5k rpm or so and then kind of pegs there all the way to redline without further increasing, although power is still climbing. I just think its a bit of overlap hence our boost doesn't continue to build to redline like an engine with a stock cam.. Would be nice if other Newman cammed owners could chime in with their logs
Hey! Thanks for the reply!
That does make sense to me, but I think I should have a bit more boost with a 17% pulley and stock headers, don't you think?
While I haven't read the whole thread, from what I gather, you installed a racier cam.
1. A cam with more duration than stock...WILL reduce pressure (boost), with no other changes.
2. A cam with more overlap than stock...WILL reduce pressure (boost), with no other changes.
3. Both one and two above, even more pressure reduction.
While I haven't read the whole thread, from what I gather, you installed a racier cam.
1. A cam with more duration than stock...WILL reduce pressure (boost), with no other changes.
2. A cam with more overlap than stock...WILL reduce pressure (boost), with no other changes.
3. Both one and two above, even more pressure reduction.
Mike
Hey Mike, thanks for the reply.
I understand that and I agree that a racier cam with more duration and overlap will cause a boost reduction.
But what about the fact that I hit peak boost at 5500rpm and then I lose about 1.5lbs of boost until the Rev limit instead of gaining?
Presume you have checked the boots around your grs cooler for any signs of leakage. Have you tried putting your stock intercooler back on to see what boost numbers you get with that?
I did that today actually, same results unfortunately, only thing that i can remember that isnt new is the charge pipe with the green gasket, maybe its that?
I understand that and I agree that a racier cam with more duration and overlap will cause a boost reduction.
But what about the fact that I hit peak boost at 5500rpm and then I lose about 1.5lbs of boost until the Rev limit instead of gaining?
One thought is belt slippage.
Though I don't know why it would come back at or near the redline.
Next thought is the pop-off (don't know the Mini name for it !) valve letting the pressure drop. Possibly a vacuum leak, weak spring.
This I could understand acting odd, pressure vs. rpm.
Did this today but i was using a new logging program, still didn´t get the hang of it, but tomorrow ill do one with my old one.
Anyway here it is, 3rd, 3rd and 4th gear. @MrBlah https://datazap.me/u/ijuve/try?log=0&data=8-16-19
Seems Im getting max 13.9 PSI at 7k rpm in 4th gear.
P.S. Idk what happend on the 4th gear log but ignore the rev drop, when the boost hits 13.87PSI it was on the redline. I suggest enabling the speed chart to guide you
probably time to put a stock intercooler / boots on the car, you can also zip tie the bpv if you have not tried that
Boots are OEM and New, BPV is a New Detroit Tuned one installed this week, already swapped for the stock cooler yesterday https://datazap.me/u/ijuve/stock-ic?log=0&data=3-6-7 (2nd and 3rd gear), and got the same results.
they are mechanical pumps, when they go out they start making terrible sounds.
could be pulley slip on the shaft, or belt slip but usually that shows up as boost dropping then coming back as it heats up and grabs again, how old is the tensioner and what size belt?
they are mechanical pumps, when they go out they start making terrible sounds.
could be pulley slip on the shaft, or belt slip but usually that shows up as boost dropping then coming back as it heats up and grabs again, how old is the tensioner and what size belt?
The tensioner and belt are 7Months old. About 5k kms. Both gates 6PK1360.
I cant find what the real length is on that belt, some it cross references to different lengths none of which look right for a 17 % pulley
try switching to a gates K060532, might need a helper to get it to fit, it will be very tight, a k060535 will fit easier but they slip for me like what you are seeing
definitly is a 535 that's probably your problem that size slips bad on my car with 17%. That's not even a gates belt it's a "bando", you can look it up with the gates parts cross reference tool
02-20-2021, 07:24 AM
