hustler's dyno thread
#164
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I wish I kept the profec-b from the jetta. I look for those non-stop. However...I think I may prefer the manual boost controller. I think the lag actually makes the car more drivable by easing power delivery. I don't want it to "slam into boost" in a few corners on various tracks. The smoother the transition, the easier to drive.
I'm going to pre-load the wastegate and see what I get. I think its remarkable that my turbo overboosts under 200kpa.
I'm going to pre-load the wastegate and see what I get. I think its remarkable that my turbo overboosts under 200kpa.
#166
patsmx5, my response was in regards to this statement of yours, which is not true:
MBT timing at 12:1 is separate from that at 11.5:1, is my point.
On a different note, "minimum best timing" is a term I havent heard before.
MBT = Max. brake torque. is a term frequently used to denote engine load, at least in engineering circles.
MBT timing at 12:1 is separate from that at 11.5:1, is my point.
On a different note, "minimum best timing" is a term I havent heard before.
MBT = Max. brake torque. is a term frequently used to denote engine load, at least in engineering circles.
My point was that if you can run 12.0 AFR and achieve LPP at 14*ATDC without detonation, then running richer isn't gonna make more power. That's my understanding. However, most engines in boost can't run enough advance at 13.0 AFR's to achieve LPP at 14* ATDC without detonation. So the mixture is richened which slows the burn and pulls a little heat out of the charge, both suppressing detonation, and allowing you to move LPP closer to 14*ATDC.
#168
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I appreciate the help and advice, but I'm telling you that i tried running richer and leaner to spool-up the turbo, with more and less advance. 12.0 was actually the happy place, but I went to 11.5 for safety. I stayed at 11.5 throughout after that.
#170
not to sound rude or anything, but ignorance is bliss I guess. Can't replace lessons learnt from 1000's of hours of dyno testing or several published SAE papers over the past 12 years between me and the people I learnt from, most of them on ion sensing and closed-loop spark control .
#171
Lets say you are at an arbit AFR of X:1.
You make 200 lb-ft peak torque at that point, and are about 3 degrees SA from the knock threshold.
Then you richen the AFR to (X-1):1.
That allows you to make 205 lb-ft, or at worst, still 200 lb-ft, but you are now about 6 degrees SA from the knock threshold.
In both cases you hit MBT timing, but in the second case you are in a safer position.
That's all I'm saying.
As to why this happens, I have no clue. I'm a test engineer, not a combustion research engineer.
As far as hustler's test results go, I have no specific experience with the miata engine, so 11.5 may indeed be the point of diminishing returns. I don't know if its the cam timing or the small bore size, but this engine seems to be pretty stout in terms of how much it can take before we see the onset of detonation.
I wish I could devote some time and money to build my own ion sensing setup. Its not too tough to do on an engine dyno, but instrumenting a vehicle could get ugly. If we had that, spark map calibration is just a matter of finding a scalar correlation between MBT (max. brake torque, not timing) and LPP from a single trip to the dyno. All subsequent tuning can be done on the street just like we do now for fuel maps.
You make 200 lb-ft peak torque at that point, and are about 3 degrees SA from the knock threshold.
Then you richen the AFR to (X-1):1.
That allows you to make 205 lb-ft, or at worst, still 200 lb-ft, but you are now about 6 degrees SA from the knock threshold.
In both cases you hit MBT timing, but in the second case you are in a safer position.
That's all I'm saying.
As to why this happens, I have no clue. I'm a test engineer, not a combustion research engineer.
As far as hustler's test results go, I have no specific experience with the miata engine, so 11.5 may indeed be the point of diminishing returns. I don't know if its the cam timing or the small bore size, but this engine seems to be pretty stout in terms of how much it can take before we see the onset of detonation.
I wish I could devote some time and money to build my own ion sensing setup. Its not too tough to do on an engine dyno, but instrumenting a vehicle could get ugly. If we had that, spark map calibration is just a matter of finding a scalar correlation between MBT (max. brake torque, not timing) and LPP from a single trip to the dyno. All subsequent tuning can be done on the street just like we do now for fuel maps.
#172
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How do dynapack dynos compare to dyno dynamics? I looked at DIY's **** and it dawned on me that they're making as much power as I am on a 1.6 w/a greddy. Maybe I'm not really a man.
#173
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It's really unfortunate how much variation exists in the world of dynos. The best you can do is try to use the same one over and over for measuring the effectiveness of your mods. Find one nearby that has good good ownership/operators and make it your home base. Baseline, mod, measure, mod, measure, etc. on the same machine.
I take dyno numbers with a grain of salt. I always figure the truth is within about ten to fifteen percent of what's reported either up or down.
Some operators will throw an extra little bit into the correction to make you happy and want to come back to them. They also get credit as better tuners if they fudge the numbers upwards (think serving the ricer community), and people will bring more cash their way. They may still do a good job tuning your car, just over-report how good.
EDIT: I just found somebody's "opinion" on another forum. I'm sure it is worth exactly what you paid for it. http://www.m5board.com/vbulletin/e39...g-dynojet.html
I take dyno numbers with a grain of salt. I always figure the truth is within about ten to fifteen percent of what's reported either up or down.
Some operators will throw an extra little bit into the correction to make you happy and want to come back to them. They also get credit as better tuners if they fudge the numbers upwards (think serving the ricer community), and people will bring more cash their way. They may still do a good job tuning your car, just over-report how good.
EDIT: I just found somebody's "opinion" on another forum. I'm sure it is worth exactly what you paid for it. http://www.m5board.com/vbulletin/e39...g-dynojet.html
Last edited by sixshooter; 03-01-2009 at 06:32 PM.
#174
great number's! i'm hoping thats what i'm making at 15psi. i just tuned it up form 10psi. same turbo,setup,pistons (wiseco/pauter rods) anyways, i don't know what some of these guys are thinking, but yes, you wan't the biggest gap that doesn't get blown out. but there's no way you're gonna be running a .040 gap. i run .029 high boost or .032 at 10-11 psi (track boost). also, don't buy -11 plugs. they start out at a bigger gap (.044) and are pointed down too far when closed to .030 or less. i use ngk bkr7es stk#6097. we need to have a little battle at the next nasa event. (tws in april for me) or i'll be at the next pca event at harris hill in 2 weeks. i think it's on the 14th. my buddy will be there too. he has a msm with a prototype begi upgrade kit (gt2860) at 10 psi.
my car made 230whp/218trq. at 11psi. i haven't gone back to the dyno to see what 15psi puts down. anyways, it's great spanking down badass cars at the track. they always come over to see what i have after i eat them up. it's great. oh, and my car had a gm boost solenoid hooked up to the link, but the solenoid went bad right after i bought the car, so i put a hallman pro mbc on it just spooled too abruptly! i bought a cheaper bleeder type turbo xs mbc and it's way easier to control coming out of the corners.
if you can, come out to the pca event so we can chew up some porsches. last time i was there, i lapped almost every car in my group. (all porsches) it was awesome.
my car made 230whp/218trq. at 11psi. i haven't gone back to the dyno to see what 15psi puts down. anyways, it's great spanking down badass cars at the track. they always come over to see what i have after i eat them up. it's great. oh, and my car had a gm boost solenoid hooked up to the link, but the solenoid went bad right after i bought the car, so i put a hallman pro mbc on it just spooled too abruptly! i bought a cheaper bleeder type turbo xs mbc and it's way easier to control coming out of the corners.
if you can, come out to the pca event so we can chew up some porsches. last time i was there, i lapped almost every car in my group. (all porsches) it was awesome.
#176
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he has a msm with a prototype begi upgrade kit (gt2860) at 10 psi.
my car made 230whp/218trq. at 11psi. i haven't gone back to the dyno to see what 15psi puts down. anyways, it's great spanking down badass cars at the track. they always come over to see what i have after i eat them up. it's great. oh, and my car had a gm boost solenoid hooked up to the link, but the solenoid went bad right after i bought the car, so i put a hallman pro mbc on it just spooled too abruptly! i bought a cheaper bleeder type turbo xs mbc and it's way easier to control coming out of the corners.
if you can, come out to the pca event so we can chew up some porsches. last time i was there, i lapped almost every car in my group. (all porsches) it was awesome.
my car made 230whp/218trq. at 11psi. i haven't gone back to the dyno to see what 15psi puts down. anyways, it's great spanking down badass cars at the track. they always come over to see what i have after i eat them up. it's great. oh, and my car had a gm boost solenoid hooked up to the link, but the solenoid went bad right after i bought the car, so i put a hallman pro mbc on it just spooled too abruptly! i bought a cheaper bleeder type turbo xs mbc and it's way easier to control coming out of the corners.
if you can, come out to the pca event so we can chew up some porsches. last time i was there, i lapped almost every car in my group. (all porsches) it was awesome.
My car won't be ready until May or so. I'd love to sign up for the Harris Hill S2k party, but I still have to work out cooling, brake ducts, and the 6-speed/3.63 bullshit.
Yeah, I am really excited about getting on the track with other turbo miatas. There were 4 in the parking lot at MSR-H today for the lemons race. There was a green NB with a BEGi kit too...like my little brother. I also had a good run with an S4...surprisingly close in a 70mph, 5th gear roll to 130. It must have been a big-turbo S4 because this car isn't slow. I'd love to know what's in that S4 if anyone knows him.
#180
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so I gapped my plugs to .040 and the car is running like a ******* caddilac now. The COPs are worth the money. I don't know that I need the TPS mod now because recovery is a non-issue under any circumstance. The car is more drivable all the way around. I may try .045 but its good enough currently.
My newest hobby is making other people drive my car so I can hear the drivability praise. MS may not be feature rich like Hydra or MoTec, but its fine for stand-alone on the cheap.
My newest hobby is making other people drive my car so I can hear the drivability praise. MS may not be feature rich like Hydra or MoTec, but its fine for stand-alone on the cheap.