gsHunter

Not sure what to say. The difference in climate can play a significant different in the amount of boost. If its humid and hot that will make a noticable difference that cold and dry. Plus it depends where you measured the boost at. It will definitely be higher near to the S/C as opposed to measuring it right near the throttle body

Mr Johnson

Look at the intercooler, especially the endcaps. From my stage II to stage III update got a brand new intercooler core and it dropped much less pressure than the old one.

I don't think I'd try running more than 9 lbs/boost on stock compression/motor. If you are ready to build it up again if it blows though go for it!

jmecbr900

The only thing is that we both have the exact same setup. Intercooler the same, pulley sizes, injectors (at one time)...everything. He sees 8lbs with a 3.12" pulley, and I see 6. ???? If it was some kind of leak somewhere, then how come I'm putting down otherwise good numbers for 6lbs of boost???? That's what's got me puzzled. At 6lbs of boost, I'm putting down 368hp which is pretty good for 6lbs. If I had some kind of pressure drop, would I experience significant HP loss too?

I don't know. I honestly think that maybe the problem lies in the crank pulley size. I don't think I have the same size as some of the other people. That's all I can figure.

BTW, I wouldn't run more than 9lbs of boost stock either. I think the compression is too high stock to go above that. I think the internals may hold it, but I think detonation will be a bigger factor. I personally aint trying it.

bitkahuna

iTrader: (20)

Jaime, you say you ses 6 lbs of boost, do you 'see' it on a guage in the car? Not wanting to overlook the obvious, maybe the guage is flakey?

jmecbr900

You know, I thought the exact same thing. The only thing that leads me to believe the gauge is accurate is that it was "seeing" 5lbs when I first dyno'd and I got 352. I dyno'd again after I switched to a smaller pulley (thinking it was going to hit 8) and the gauge said 6lbs. The dyno kinda confirmed that by only going up to 368. If 5lbs netted about 110HP over stock, then it stands to reason that 1lb = about 20hp. Which means that the gauge is possibly right. I only gained 16 HP which is pretty close to the average of 20 from before. The gauge is not a cheapy one, it's an Autometer Phantom series gauge. In my experience they have usually been pretty accurate. Kinda like almost pregnant now that I think about it!!???lol.

Maybe you're right though. What do you think? I guess I can go to another dyno I know has a device to measure the actual vaccum.

bitkahuna

iTrader: (20)

Dude I barely know how to spell supercharger so your guess is as good as mine, but I do know about Occam's razor (the simplest explanation is usually right).

jmecbr900

Sometimes you're so funny!!!!

TTurboPimp

iTrader: (12)

gshunter, I have plenty of room with my 370's with what Im running now, I have no doubt that I could go higher in boost with these injectors not being maxed out. I have been tlaking with jamie back and forth since we both started this project, and we have had some really strange difference in outcomes with pretty much the exact same set up. His tuner said that his car was running rich throughout the entire band(if Im not mistaken, Jamie, correct me if Im wrong on this).......My tuner said I was running out of fuel at the top, I could see on the dyno sheet where I was running lean and the power was dropping off.....this is with both of us using the 310's the kit came with. Keep in mind, he is on ly seeing 6 lbs of boost, so this might account for that.
I went up to the 370's just to eleviate the chance of detonation at max boost, the 370's solved the problem, but they didnt give me much more power....which I was hoping to get with adding feul up top where I was lean before. They do give me the peace of mind of knowing I wont be lean when really pushing the car hard, ecspecially with the weather changing colder now. RMM would have included any size injectors that I wanted with the original kit at no extra cost, I just didnt know what to go with at that time....trial and error.

jmecbr900

Just uploaded my "old" dyno chart from the first few pulls with the "7lb" pulley on.

https://www.clublexus.com/gallery/sh...cat=500&page=1

Notice on the bottom that the A/F is almost dead straight once it's hammered. Notice also that when the car hits the rev limiter, the A/F kinda rises slightly. This is just before our last run which I ran a 352.8. For whatever reason, on my car with 310's it's running rich. In TT's car, it ran slightly lean on the top end. This is kinda odd since we both have the same identical setup.

I was so ticked off that I didn't hit 8lbs of boost with the smaller pulley that I left the dyno and forgot my printout. It showed slightly higher HP/TQ readings, and the A/F was identical to this one....flat @ 12 all the way thru.

We'll see next time.