Yep, I just pulled it off tonight and put back on the lower boost pulley. The cold start injector worked pretty well but on a trip earlier this week to and from Greenville, SC I did hear a little knock occasionally. It was minimal and typically non-existent. But as I said before, a little knock is too much.

So I cooled the engine down and did the swap which is kinda a pain. You replace the alternator pulley to do this. So you have to finagle the alternator to get it on and off with the SC drive shaft in the way.

But now I am at the lower boost, albeit not as low as I thought. I was seeing 4 PSI, maybe a little more. This might be partially due to the belt staying seated properly now. I dropped the fuel pressure down and tuned for about 0% fuel trim. I then went for a drive and it pulled hard. There was a little less pull down low but the upper end felt about the same. My top end was probably being killed by the knock.

I'm not going to let all of my work go to waste. I know that the mixture goes leaner after the VTEC solenoid opens so the Comptech regulator is probably set to take care of the upper end more so. So I might try to lean it out a little with the FPR and still retain the cold start valve. This way the bottom end might be helped while retaining about the same power up high, or hopefully so.

But this can be checked (and tuned) on the dyno so I will go ahead and schedule an appointment for the roller test.

 

How much were you seeing with the higher boost pulley?

 

Steve... .we need some kind of boost-dependant timing retard... currently unavailable. I saw knock at 6'ish PSI of boost (hence using 103 octane when I did push that much)... also the car runs leaner as well - injectors can't handle that.... as you are well aware of.

Good luck at the dyno/track... I know its not the greatest feeling running at altitude... but it should still be good. You can always correct for this.... I ran at Bakersfield which was 900ft.... so 0.15s or something like that... so figure 0.2s at least where you are at!

 

good luck at the track steve sorry to hear you pulled the upgraded pulley.im sure within this year their will be a solution so you can run higher boost.i ordered the lightweight flywheel so ill let you know the results next week.

 

5.0 - 6.0 PSI (depending on the gear) and it is does vary with temperature as expected. This morning I saw 4+ in a 3rd gear. But this was just after sunrise and with temps in the mid 60's. But on the way home it was near 90 and sunny so the same type of pull netted just shy of 4 PSI.

One interesting point though related to the IMRC especially now with warmer temps. I was watching the boost gauge and it would jump 0.5 - 1.0 PSI when the IMRC opened (right around 4k revs). Normally I would consider less boost to be better because it means the engine is using the supplied air well. But if I am not mistaken, it pulls harder when the boost goes up. This is the opposite of what I would think as the amount of air flow has not (and cannot) changed through the blower and higher boost would indicate less air being used.

It was not as noticeable in cooler temps but jumps out at you as the ambient climbs. This will require further testing, most likely on the dyno. I have always been curious about the difference in the functioning of the IMRC under boost and on the dyno would be the best place to see what happens.

 

We need a lot.

Makes sense that at 6+ PSI you heard knock even with an intercooler. As I see it when at about 5 PSI and then on. And at these low levels of boost... There are ways we can get extra fuel in there but if I were to spend $500 I might as well spend $1000 and have complete control over fuel and ignition.

 

You and allmotor need to let us other know what that combo is like. Have fun with it...

 

I'm a little weary of using the flywheel AND the UR pulleys.... that's a lot of mass taken off the crank... nearly 30lbs!! The dampening effect for all the shockwaves the crank experiences is highly reduced... not too sure what will happen in the long term!

Comptech has been lagging for three weeks on this!! Acura doesn't have flywheel bolts, so Comptech had ARP make them... and they will receive those on Monday... so I expect to have the flywheel by end of next week.

 

i dont think the shockwaves would be bad do to the springs on the clutch to absorb the nvh.comptech said all they did was reverse engineering since the dual mass flywheel has springs in it to dampen the waves so what comptech did was just reverse it very smart.i wouldnt expect any long term effects on the crank or transmission itself and comptech has told me their is no nvh at all i guess due to their setup.anyway the way me steve and you allmotor are going well probably pull the motor out to bore the block etc etc lol