SOT SC kit with too much boost
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From: Wetumpka, Alabama
Originally Posted by vader1,Jul 13 2009, 11:32 AM
Just went to burn in the Fuji a little more. A couple hard pulls, 11.2 peak boost. Stumped.
Think the Fujitsubo is gonna be too loud for me too.
Second exhaust installed and probably put up for sale within a week. Fool me twice shame on me.
Think the Fujitsubo is gonna be too loud for me too.
Second exhaust installed and probably put up for sale within a week. Fool me twice shame on me.
Joined: Oct 2002
Posts: 8,044
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From: South Florida
quick question, motors are essentially air pumps, would different displacements for our two motors mean that they pump different volumes of air relative to the rpm u are at?
would a 126 pulley on an ap1 be different then a 126mm pulley on an ap2 becuase of the volume of air each motor consumes per revolution?
would a 126 pulley on an ap1 be different then a 126mm pulley on an ap2 becuase of the volume of air each motor consumes per revolution?
Joined: Oct 2002
Posts: 8,044
Likes: 6
From: South Florida
gotcha, well the emu is prolly adjusting based on the oem map sensor. so if possible, log that, rpm, air temp, and knock.
emu is load based vtec at i think 4k. i know its sounds dumb, but floor it in like 3rd at 3400rpm and listen for the vtec transiion. theres a audible tone change when cam swap happens.
eitherway, lets try and see what/where in rev range these peaks are happeneing. a 9.2 peak but consistent 8would be ok. possibly, if vtec is kicking in at 6k still, your peak of 9,2 is right before there, as low cam is inefficient and that would explain the peak. need to see a log meng!
emu is load based vtec at i think 4k. i know its sounds dumb, but floor it in like 3rd at 3400rpm and listen for the vtec transiion. theres a audible tone change when cam swap happens.
eitherway, lets try and see what/where in rev range these peaks are happeneing. a 9.2 peak but consistent 8would be ok. possibly, if vtec is kicking in at 6k still, your peak of 9,2 is right before there, as low cam is inefficient and that would explain the peak. need to see a log meng!
Joined: Oct 2003
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From: MAHT-O-MEDI
Originally Posted by camuman,Jul 13 2009, 12:02 PM
second, i tell ya, i have yet to see/hear an exhaust that was as quiet as stock cruising but mean sounding WOT. prolly do stock exhaust, berk hfc, and maybe a header down the road.
I can not prove that the Berk cats make some of these exhausts boomier than a stock cat or TP would, but have had 2 exhausts on this car with the Berk HFC, the "quiet" Invidia Q300 on an NA car, and the FUji on the SC'ed car. Both to me sound louder and boomier than anyone else describes them so its either just me or the other variable, the Berk HFC.
I am not trying to badmouth the Berk product, it seems like a solid piece, and it flows close to a test pipe while giving some minor bunny hugs and keeping the raw exhaust smell to a minimum. I was happy with it as my only exhaust modification, and my exhaust tone stock got slightly lower. But I think that effect is exaggerated with an aftermarket and takes some of these things into the subwoofer frequencies.
I guess I will have to be happy being a little slower but have peace and quiet. I do think that this Fuji would be a great exhaust on an otherwise stock car.
Joined: Oct 2003
Posts: 11,950
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From: MAHT-O-MEDI
Originally Posted by camuman,Jul 13 2009, 02:04 PM
gotcha, well the emu is prolly adjusting based on the oem map sensor. so if possible, log that, rpm, air temp, and knock.
emu is load based vtec at i think 4k. i know its sounds dumb, but floor it in like 3rd at 3400rpm and listen for the vtec transiion. theres a audible tone change when cam swap happens.
eitherway, lets try and see what/where in rev range these peaks are happeneing. a 9.2 peak but consistent 8would be ok. possibly, if vtec is kicking in at 6k still, your peak of 9,2 is right before there, as low cam is inefficient and that would explain the peak. need to see a log meng!
emu is load based vtec at i think 4k. i know its sounds dumb, but floor it in like 3rd at 3400rpm and listen for the vtec transiion. theres a audible tone change when cam swap happens.
eitherway, lets try and see what/where in rev range these peaks are happeneing. a 9.2 peak but consistent 8would be ok. possibly, if vtec is kicking in at 6k still, your peak of 9,2 is right before there, as low cam is inefficient and that would explain the peak. need to see a log meng!
I would be ok with an occasional 9.2 spike, but the 11.2 was the highest yet and kind of out of my comfort range for long term.
Joined: Oct 2003
Posts: 11,950
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From: MAHT-O-MEDI
Quote from WLaruents thread:
Just got the car back from the body shop (AP2 front conversion and repaint) - have not tested out the smaller pulley's yet. However, at sea level and cooler temps I am seeing 9-10 psi on the boost gauge.
And quote from Mark on the sale of the kit on another board:
Blower speeds at redline
AP1
17313-126mm crank pulley(standard one with the kit)
18550-136mm crank pully
19511-142mm crank pully
AP2
15389-126mm crank
16489-136mm crank
17334-142mm crank
manufacture suggested blower speed is 17280
Just a guess that there is going to be some variation in boost due to air temps, but look at the vast difference in rotational speed from the 126 pulley from an AP1 to an AP2. It seems pretty logical to me anyway that you could expect higher boost levels from the "stock" pulley on an AP1 versus an AP2. Even though the engines have differences in compression, displacement, cams and header, the speed of the blower is ~13% higher on the AP1 with the same pulley.
Could it be safe to assume that since WLaurent, Neptuner and I have all seen boost levels at 10psi and up from the 126mm pulley that maybe the assumption that it is a ~6-8 pound pulley might be a little low of an estimate on the AP1 and what we are seeing is normal? My high readings are in the realm of "spikes" when running it all the way to redline (which WLaurent posted he rarely does) So maybe there is nothing wrong with my car or Neptuners and that this is what one could expect from a 126mm pulley.?.?.?
Its been shown to produce at least 10psi on three AP1's.
I like the power with this kit and that is even without a custom tune yet, but I almost think a smaller pulley in maybe the 118-120mm size might be good for the "stock" one for the AP1 kit. Or at least the option to get one would be good. Don't know how to source something like that if anybody is in the know feel free to let me in on the secret. If this is what psi to expect out of the 126mm then maybe I got a "stage 2" boost upgrade for free. I don't see it as a serious problem but having a smaller pulley for when the weather gets cooler here would be a decent idea. The coldest the car sees is 40 degrees but that could push the boost even beyond 11.2psi. I really don't ever want to push ~14-15psi into the car.
Just got the car back from the body shop (AP2 front conversion and repaint) - have not tested out the smaller pulley's yet. However, at sea level and cooler temps I am seeing 9-10 psi on the boost gauge.
And quote from Mark on the sale of the kit on another board:
Blower speeds at redline
AP1
17313-126mm crank pulley(standard one with the kit)
18550-136mm crank pully
19511-142mm crank pully
AP2
15389-126mm crank
16489-136mm crank
17334-142mm crank
manufacture suggested blower speed is 17280
Just a guess that there is going to be some variation in boost due to air temps, but look at the vast difference in rotational speed from the 126 pulley from an AP1 to an AP2. It seems pretty logical to me anyway that you could expect higher boost levels from the "stock" pulley on an AP1 versus an AP2. Even though the engines have differences in compression, displacement, cams and header, the speed of the blower is ~13% higher on the AP1 with the same pulley.
Could it be safe to assume that since WLaurent, Neptuner and I have all seen boost levels at 10psi and up from the 126mm pulley that maybe the assumption that it is a ~6-8 pound pulley might be a little low of an estimate on the AP1 and what we are seeing is normal? My high readings are in the realm of "spikes" when running it all the way to redline (which WLaurent posted he rarely does) So maybe there is nothing wrong with my car or Neptuners and that this is what one could expect from a 126mm pulley.?.?.?
Its been shown to produce at least 10psi on three AP1's. I like the power with this kit and that is even without a custom tune yet, but I almost think a smaller pulley in maybe the 118-120mm size might be good for the "stock" one for the AP1 kit. Or at least the option to get one would be good. Don't know how to source something like that if anybody is in the know feel free to let me in on the secret. If this is what psi to expect out of the 126mm then maybe I got a "stage 2" boost upgrade for free. I don't see it as a serious problem but having a smaller pulley for when the weather gets cooler here would be a decent idea. The coldest the car sees is 40 degrees but that could push the boost even beyond 11.2psi. I really don't ever want to push ~14-15psi into the car.
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From: Mesa
Best way to source a smaller pulley is to talk to James at SOT - they can have them made in many configurations.
I am currently running the 135mm pulley and see 8-10 psi in the current hot as hell AZ summer @ 1200' ASL. When it was cooler (60-70 degrees) I was seeing 11-12 psi. At sea level I was seeing 13-14 psi with 60-70 degree temps.
I recently took the car on a ride from Phoenix, through Grand Teton and Yellowstone. 2600 miles through varied temperatures and elevations. Above 7500' ASL I was only seeing around 6-7 psi peak boost in the crip morning air. At around 5000' ASL I was seeing 7-8 in the cool 50 degree morning air and 6-7 when it heated up to 80-90 degrees.
The short summary is that both temperature and elevation have considerable effect on the boost you will see. I think temperature has a bigger effect. Cool dense air in, higher boost.
One added note for large elevation changes and the EMU - I had to tweak my tune slightly once I got above and stayed above 5500' ASL. With my 1200' tune (Phoenix) I was not adding fuel on the map until about 0.3 psi - the PCM would adequately manage the fuel requirements below that. After being above 5500 feet I started to see the car going a little lean from -4"/hg up to 0 psi. I changed my fuel map to start adding fuel in the -0.2 psi range and everything was perfect. Of course when I got home I had to change it back.
I think that the OEM MAP sensor/PCM does not recalibrate its ATM/Zero very well, possibly not at all. I crossed the great divide 6 or so times hitting elevations of 9000' ASL. I wonder how big of a turd the NA car would have been at those elevations.
I am currently running the 135mm pulley and see 8-10 psi in the current hot as hell AZ summer @ 1200' ASL. When it was cooler (60-70 degrees) I was seeing 11-12 psi. At sea level I was seeing 13-14 psi with 60-70 degree temps.
I recently took the car on a ride from Phoenix, through Grand Teton and Yellowstone. 2600 miles through varied temperatures and elevations. Above 7500' ASL I was only seeing around 6-7 psi peak boost in the crip morning air. At around 5000' ASL I was seeing 7-8 in the cool 50 degree morning air and 6-7 when it heated up to 80-90 degrees.
The short summary is that both temperature and elevation have considerable effect on the boost you will see. I think temperature has a bigger effect. Cool dense air in, higher boost.
One added note for large elevation changes and the EMU - I had to tweak my tune slightly once I got above and stayed above 5500' ASL. With my 1200' tune (Phoenix) I was not adding fuel on the map until about 0.3 psi - the PCM would adequately manage the fuel requirements below that. After being above 5500 feet I started to see the car going a little lean from -4"/hg up to 0 psi. I changed my fuel map to start adding fuel in the -0.2 psi range and everything was perfect. Of course when I got home I had to change it back.
I think that the OEM MAP sensor/PCM does not recalibrate its ATM/Zero very well, possibly not at all. I crossed the great divide 6 or so times hitting elevations of 9000' ASL. I wonder how big of a turd the NA car would have been at those elevations.