Max Power Standard Cams dyno problems help needed
#21
OP, what is your injector duty % and what size injectors are you running? It is possible that your clutch isn't holding and it's slipping through the powerband causing low numbers. If you're duty cycle % is lower than it should be for 21psi then maybe there is something choking the engine. Dunno, I'm trying to think of any scenario here
#22
mkturbo.com
iTrader: (24)
Join Date: May 2006
Location: Charleston SC
Posts: 15,178
Total Cats: 1,681
The 3071 isn't the problem here though. I agree that a .63 turbine would be much better with that turbo on a miata. However there is something wrong in his setup it's making 270whp @21psi.
OP, what is your injector duty % and what size injectors are you running? It is possible that your clutch isn't holding and it's slipping through the powerband causing low numbers. If you're duty cycle % is lower than it should be for 21psi then maybe there is something choking the engine. Dunno, I'm trying to think of any scenario here
OP, what is your injector duty % and what size injectors are you running? It is possible that your clutch isn't holding and it's slipping through the powerband causing low numbers. If you're duty cycle % is lower than it should be for 21psi then maybe there is something choking the engine. Dunno, I'm trying to think of any scenario here
#24
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,664
Total Cats: 3,013
Not by this much power at this power level. He's got a major problem he hasn't found yet.
Possibilities include, but aren't limited to, cam timing (yes I know he checked it but I don't have enough fingers and toes to count the number of times people have "checked" it and they were looking at it wrong), spark timing (we don't even have a log so we don't know if MAT retard or something else is intervening), broken ring (haven't seen a compression test), bent or burned valve (haven't seen a leakdown test), restrictive exhaust (don't have a clue what he's running), don't know where he's got the boost gauge plumbed to the system, O2 gauge may be calibrated wrong and it's running too rich or lean, AFR targets may be wrong, exhaust leak, boost leak, spark blowout, mismatched injector, or something else.
Post a log of it boosting. Post the tune. Post pictures of cam and crank timing marks aligned. Let's start there. These are the basics.
Then we can look at compression/leakdown tests if necessary and proceed from there.
And so it is clear, chassis dyno numbers in Europe ALWAYS read 15-30% higher than American dyno numbers. This is because the European standard is to take the measured wheel horsepower and add to it to guess what the engine is making before the transmission, driveshaft, differential, CV axles, wheel hub, brake drag, and tire rolling resistance are added.
Possibilities include, but aren't limited to, cam timing (yes I know he checked it but I don't have enough fingers and toes to count the number of times people have "checked" it and they were looking at it wrong), spark timing (we don't even have a log so we don't know if MAT retard or something else is intervening), broken ring (haven't seen a compression test), bent or burned valve (haven't seen a leakdown test), restrictive exhaust (don't have a clue what he's running), don't know where he's got the boost gauge plumbed to the system, O2 gauge may be calibrated wrong and it's running too rich or lean, AFR targets may be wrong, exhaust leak, boost leak, spark blowout, mismatched injector, or something else.
Post a log of it boosting. Post the tune. Post pictures of cam and crank timing marks aligned. Let's start there. These are the basics.
Then we can look at compression/leakdown tests if necessary and proceed from there.
And so it is clear, chassis dyno numbers in Europe ALWAYS read 15-30% higher than American dyno numbers. This is because the European standard is to take the measured wheel horsepower and add to it to guess what the engine is making before the transmission, driveshaft, differential, CV axles, wheel hub, brake drag, and tire rolling resistance are added.
#25
Tweaking Enginerd
iTrader: (2)
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,778
Total Cats: 360
~sigh~
The turbo absolutely can be the problem here. Notice how we haven't seen a log or dyno yet? Probably because he doesn't hit his "21psi" until 6krpm or later.. turbo power potential is moot if you aren't in the right spot on either the compressor or turbine map. The 3071 compressor is perfectly capable of producing 270hp at a PR of 2.5. That turbine probably needs 200hp+ to get going.
The turbo absolutely can be the problem here. Notice how we haven't seen a log or dyno yet? Probably because he doesn't hit his "21psi" until 6krpm or later.. turbo power potential is moot if you aren't in the right spot on either the compressor or turbine map. The 3071 compressor is perfectly capable of producing 270hp at a PR of 2.5. That turbine probably needs 200hp+ to get going.
#26
And so it is clear, chassis dyno numbers in Europe ALWAYS read 15-30% higher than American dyno numbers. This is because the European standard is to take the measured wheel horsepower and add to it to guess what the engine is making before the transmission, driveshaft, differential, CV axles, wheel hub, brake drag, and tire rolling resistance are added.
FWHP is a fudge because people like bigger numbers for bragging rights, and that's what the manufacturers use (although I'd imagine their numbers are properly measured, rather than made up...)
#27
~sigh~
The turbo absolutely can be the problem here. Notice how we haven't seen a log or dyno yet? Probably because he doesn't hit his "21psi" until 6krpm or later.. turbo power potential is moot if you aren't in the right spot on either the compressor or turbine map. The 3071 compressor is perfectly capable of producing 270hp at a PR of 2.5. That turbine probably needs 200hp+ to get going.
The turbo absolutely can be the problem here. Notice how we haven't seen a log or dyno yet? Probably because he doesn't hit his "21psi" until 6krpm or later.. turbo power potential is moot if you aren't in the right spot on either the compressor or turbine map. The 3071 compressor is perfectly capable of producing 270hp at a PR of 2.5. That turbine probably needs 200hp+ to get going.
He needs to post a log like everyone is saying
#28
I am trying to get car back onto dyno, but looks like base timing when we locked it at 10 to set and the timing light we used was no good as i have tested it with 2 other lights and both show 6 deg base when supposed to be locked at 10.
Full 3 inch exchaust no cat 1 muffler at rear that i have checked has not collapsed etc etc.
Full fuel system dw300 pump fuel reg changed (boost refrenced) and bosch 1000cc injectors.
Good to see other people have made over 400whp on stock head cams.
Turbo is not laggy in my books. Would be on fullboost by 5000rpm.
Full 3 inch exchaust no cat 1 muffler at rear that i have checked has not collapsed etc etc.
Full fuel system dw300 pump fuel reg changed (boost refrenced) and bosch 1000cc injectors.
Good to see other people have made over 400whp on stock head cams.
Turbo is not laggy in my books. Would be on fullboost by 5000rpm.
#32
andym i have played with it before when setting up my new 36 2 trigger wheel and all tests of timing done with it locted at 10deg in the tune.
patsmx5 intercooler is around 20 inches long by 10 inch high. Cams and crank all line up have checked them 20 times all the dots align etc etc. I am going to make one of those pvc boost leak testers that go over the front compressor housing and hook up to your air compressor to check for leaks
patsmx5 intercooler is around 20 inches long by 10 inch high. Cams and crank all line up have checked them 20 times all the dots align etc etc. I am going to make one of those pvc boost leak testers that go over the front compressor housing and hook up to your air compressor to check for leaks
Thread
Thread Starter
Forum
Replies
Last Post