slash128's Top Mount Build
#502
n3rd
Thread Starter
I am working on my fine tuning. I have a real dyno scheduled for next Tuesday. Here is the latest from this afternoon. Power dip between 6K-7K I think might be due to timing getting slightly pulled. I am seeing boost peak at 17psi.
GoPro video, still working on the best placement and settings, will look into Yomoms mic suggestion:
GoPro video, still working on the best placement and settings, will look into Yomoms mic suggestion:
Last edited by slash128; 04-30-2014 at 12:08 AM.
#504
n3rd
Thread Starter
#511
Boosted Kiwi
iTrader: (2)
Not sure i believe that but here goes anyway ....
If you have a spare rotor and iron and look what is happening when the apv port is still open (and have a bit of a think about it ) you can see for yourself that how well the APV port works is determined by how fast the rotor is moving past it .
If the rotor is moving slowly air will backtrack into the intake , as compression starts before the port is closed.
The faster the rotor moves the less tendency there is for this to happen to any significant degree.
The acceleration of the engine in a turbo car being much faster than an NA means the time it takes for the DC motor to open the valve becomes a factor , so setting the opening rpm a little earlier has some benefit .
As far as testing this ... I tested it years ago but when you brought it up not that long ago, I tested it again ........ with the same result .
If you have a spare rotor and iron and look what is happening when the apv port is still open (and have a bit of a think about it ) you can see for yourself that how well the APV port works is determined by how fast the rotor is moving past it .
If the rotor is moving slowly air will backtrack into the intake , as compression starts before the port is closed.
The faster the rotor moves the less tendency there is for this to happen to any significant degree.
The acceleration of the engine in a turbo car being much faster than an NA means the time it takes for the DC motor to open the valve becomes a factor , so setting the opening rpm a little earlier has some benefit .
As far as testing this ... I tested it years ago but when you brought it up not that long ago, I tested it again ........ with the same result .
Last edited by Brettus; 04-30-2014 at 01:54 AM.
#512
No respecter of malarkey
iTrader: (25)
I was serious and can see your point, though I'm not entirely sure that I'd agree. The easy test is to make two test dyno runs. One run with the APV set to open early and another run with it set to open late ( maybe say 5000 rpm and 7500 rpm). The overlay the two dyno runs and see where they cross. The set the APV open point about 150 - 200 rpm sooner than the crossover point
#513
Boosted Kiwi
iTrader: (2)
I was serious and can see your point, though I'm not entirely sure that I'd agree. The easy test is to make two test dyno runs. One run with the APV set to open early and another run with it set to open late ( maybe say 5000 rpm and 7500 rpm). The overlay the two dyno runs and see where they cross. The set the APV open point about 150 - 200 rpm sooner than the crossover point
Doing a dyno would ,IMO, be LESS accurate because the ramp rate of the dyno would affect the result.
I set mine up to get the best result on average between 2nd and 3rd as they are the most favored gears in terms of straight line acceleration.
If you open it at around 4000 you can actually feel the loss in power with your butt dyno ... It is significant.
#515
Boosted Kiwi
iTrader: (2)
Actual power is different in every gear and things like how fast the APV opens hava a pronounced effect in first and second gear due to the how fast the engine is accelerating.
#516
patiently awaiting dyno day...
#517
n3rd
Thread Starter
Me too I am taking care of misc odds and ends. Like bleeding my clutch. What a PITA! Anyone got any tricks for getting a wrench on that thing? I got some speed bleeders but still getting a wrench on that thing is a pain. Also changed tranny and diff oil. Not just for dyno day but planning for my maiden autocross event Memorial Day weekend.
Last edited by slash128; 05-02-2014 at 11:32 PM.
#518
autox in a turbo8.. have fun lol Sounds like you need a track day. I would probably run lower boost levels though under extended run times you will experience on track. things get hot fast. Make sure to get video of autox shenanigans
#519
n3rd
Thread Starter
Ya I don't know what I am getting myself into but I went out to watch last weekend and it looked like fun. I'm not out for competition, just an opportunity to drive the car and have fun And there will be video as I know have my GoPro...
Last edited by slash128; 05-03-2014 at 10:19 AM.
#520
No respecter of malarkey
iTrader: (25)
Me too I am taking care of misc odds and ends. Like bleeding my clutch. What a PITA! Anyone got any tricks for getting a wrench on that thing? I got some speed bleeders but still getting a wrench on that thing is a pain. Also changed tranny and diff oil. Not just for dyno day but planning for my maiden autocross event Memorial Day weekend.
You can bleed it yourself without a speedbleeder because the clutch pedal will go and stay to the floor when the bleed nipple is open. You will get a lot of exercise running back & forth around the driver door to open nipple, go to pedals and push clutch pedal to floor, go back and close nipple, go back to pedal and pull up, go back to nipple and open, and so on ... rinse and repeat
#522
n3rd
Thread Starter
I can usually get a short closed-end 10mm wrench on it before slipping the bleeder hose on the nipple and trapping the wrench in place. You have to position the wrench properly so you can open and close the nipple within the same rotational swing. So you would typically break it open first, close lightly, position wrench, then fit bleeder hose.
You can bleed it yourself without a speedbleeder because the clutch pedal will go and stay to the floor when the bleed nipple is open. You will get a lot of exercise running back & forth around the driver door to open nipple, go to pedals and push clutch pedal to floor, go back and close nipple, go back to pedal and pull up, go back to nipple and open, and so on ... rinse and repeat
You can bleed it yourself without a speedbleeder because the clutch pedal will go and stay to the floor when the bleed nipple is open. You will get a lot of exercise running back & forth around the driver door to open nipple, go to pedals and push clutch pedal to floor, go back and close nipple, go back to pedal and pull up, go back to nipple and open, and so on ... rinse and repeat
Last edited by slash128; 05-03-2014 at 11:26 AM.
#523
n3rd
Thread Starter
So Brettus and Fazda, you mentioned that street tunes run lean on the dyno. How lean? Is it because the dyno is going to cross load/rpm ranges due to ramp rate that a street tuned car would not see, so they don't get tuned? Or ? Just trying to keep from dying on the dyno
Last edited by slash128; 05-03-2014 at 11:51 AM.
#525
my simple understanding is that the dyno is like going up hill, so your at higher loads at lower rpms, so you hit much different spots in the tune, that doesn't sound exactly right, but its something similar