10 pound pully report UPDATE

[98GREENGLOW]

Ive had it in for roughly 2 weeks and my general impression of it is very good at this point.

Upon first installment I could get no more than 4 pounds of boost with an inch-inch and a half of play in my belt.

I then tightened the belt to one inch of play and got 7 pounds of boost. This felt good but I wanted more. I was going to tighten the belt down to the recommended half inch play when I realized that the current belt of 104.5 inches was too lond and could not be tightened anymore without damaging my idler pully. I went and bought a 103 inch Dayco belt and put it on. The results were amazing!!!!

I got 10 psi in first gear and 10 psi in second gear. 3rd gear will drop to 4-5 and build to 51/2 before I hit the speed sensor at 95 mph and 4800 rpm.

I have tried to dyno in third gear but because of my speed sensor I can not build boost in 3rd gear like I can in first and second gear.

The results were 207 rwhp with 4-5 pounds of non intercooled boost at 4800 rpm's and 95 mph. The temp outside was 88 degrees.

I was disapointed that I couldnt get a real third gear dyno because of my speed sensor kicking in so low. It is very important that my car gets to the 6000rpm redline because my boost is rpm dependent. If I could get my car to the 6000 rpm redline my boost in third gear would be between 7-10 psi and would significantly affect my dyno numbers. There is currently a new pcm plan in the works.

I then decided to do my final run in second gear. The personell at the shop insisted that I didnt do this . They said that I would dyno much lower and be wasting my last pull. Normaly on an NA car this would be true. But when you can build 7-10 pounds in second gear vrs 4-5 pounds in third gear then there may be a different outcome.

The results were 217 rwhp with 7-8 pounds of boost at 60 mph and 5600 rpm's. I was not very happy with these numbers at the time but now realize that 217 in second gear is not bad and theres plenty of room to grow in third gear.

The 10 pound pully held for 1 day and then slipped down to 8 pounds. All new belts stretch out at first. I tightened it down to the recommended half inch of play and then the 10 pounds returned.

2 days later this slipped down to 8 pounds again. I sprayed on some Napa auto dressing and the 10 pounds returned again. This time it lasted for 3 days before slipping down to 7 psi.

I was gonna tighten the belt for the final time (usualy by the 3rd time you tighten a new belt it's done all the stretching it gonna do) But I felt happy with the 7 pounds that comes on so much more instantly than my old 3.1(6 pound ) pully and left it alone. The 7 pounds has has lasted for the last week with no hint of slip. It will ocassionaly even catch and give me 8 pounds.

The reason I dont tighten it one last time to always have 10 pounds of goodness is because Im scared that 10 pounds f nonintercooled boost may be putting my car on borrowed time. Once I get a BLOW OFF VALVE and the SMC I will tighten her down for the final time. Until then Im very happy with the 7-8 psi and I highly recommend that eveyone with a powerdyne spend the 125$ for a 2.70-2.90 pully from ASP racing and then do the JOHNDPOWERRAP.

Words cannot descibe the feeling of knowing your powerdyne is slipping and still getting 7 pounds of IMMEDIATE BOOST. especialy when comparing it to the old 3.1 pully that would slip down to 4 measily pounds or build up to 6-7 pounds when the belt was super tight and only last for a day.

Well Thats all I know so far. I will be ordering a new pcm soon and then will go back and see what my car can really dyno in third gear with 7-10 pounds of boost.

[ February 01, 2004: Message edited by: 98GREENGLOW ]</p>

[Shirl]

You might want to think about getting a breather since you're going to have blowby under more boost.

[Mighty Thor]

This update thing you do is great. I like how much you improved.

I agree with Shirl. Be careful of blowby.

[98GREENGLOW]

Been 3 days and 7-8 psi holding strong. VERY TEMPTED to make belt have half inch play and get 10 pounds................Must wait till I get BOV. BTW....... Whats the differance between a blow off valve and a by pass valve? If theres a differance..... Which one should I order?

[John_D.]

<blockquote>quote:</font><hr>Originally posted by 98GREENGLOW:
Been 3 days and 7-8 psi holding strong. VERY TEMPTED to make belt have half inch play and get 10 pounds................Must wait till I get BOV. BTW....... Whats the differance between a blow off valve and a by pass valve? If theres a differance..... Which one should I order?<hr></blockquote>

Blow-off vents to the atmosphere.

Bypass routes the air back to the blower suction side.

If you've already metered the air (maf sensor before the blower, also called draw-through), then blow-off throws your air-flow reading out of whack, because you're measuring air that's not actually going into the engine. So bypass is best, if you have a draw-through, because the air is recirculated and the maf sensor reading will be correct.

On the other hand, if you meter the air after the blower (blow-through), which is what your stock tb does, then you can use a blow-off or a bypass. The advantage of being able to use a blow-off, is you don't send hot air back around to the suction side of the compressor, to be sent through and made even hotter...

[ReodDai]

Last time I checked their were atmospheric and non atmo blowoff valves. (ei one wastes the air into the engine bay, the other brings it back into the intake to reduce lag when shifting)

[98GREENGLOW]

So since I use the stock throttle body I can get a BOV right? The BOV makes the kool sound and the BPV dosent? Will these effect my boost readings at all? Also.... How dose the valve on the BOV know when too open ? I wouldnt want to loose boost. Thanks for any replys.

[John_D.]

Yep, with your stock setup (blow-through maf) you can use a bov. And it will be louder than a bypass valve... [img]smile.gif[/img]

It knows because it is adjusted to open when a set amount of pressure is applied. You can probably find some pics of various bov's by doing a search on ebay, and it will give you an idea.

You probably want to get an adjustable one.

[98GREENGLOW]

UPDATE....... Today I took her for a spin and was getting 7 pounds of boost. I knew that I shouldnt but I had too. I had to feel the 10 pounds even though Im not intercooled and dont have a BOV yet.

So I pulled her over and thightened her down for what I felt should have been the last time of tightening. I made my belt have an half inch of play and slammed the gas.

1st gear was 10 pounds!
2nd gear was 7 pounds?
3rd gear was 5 pounds?

I was like WTF???? THAT SHOULD HAVE BEEN THE LAST TIME I TIGHTENED IT. PERIOD!!!!!!!

Then I took a good look at my tensioner pully and realized that the pully had slipped up to were it was before I tightened it down. So basicly what Im trying to say is that THE REPORTS I GAVE EARLIER ABOUT THE BOOST GOING DOWN TO 7-8 PSI FROM A STRETCHING BELT/SLIPPING PULLY ARE FALSE! IT WAS NEVER THE PULLYS GROOVES NOT CATCHING OR THE BELT STRETCHING. IT WAS SIMPLY MY TENSIONER PULLY NOT BEING TIGHT ENOUGH AND SLIPPING UP.

The first thing I always do to check for slippidge is see how much play is in the belt. Lately I had been noticing that there was always an inch of play in the belt ......Even days after I tightened it. I thought this was the new belt stretching but I was wrong.

THIS IS A GOOD THING!!!!!!!! This shows that even with a slipping tensioner pully 8 pounds is still obtainable. I will make sure my tensioner wont slip up any more with some good tightening and see how long 10 pounds can really last. IM THINKING THAT BASED ON HOW GOOD THE BOOST HELD AT 7-8 POUNDS WITH A HOLE INCH OF PLAY IN THE BELT THANKS TO A SLIPPING TENSIONER, THAT WITH THE BELT ACTAULY STAYING AT AN HALF INCH OF PLAY 10 POUNDS SHOULD LAST TILL YOU DECIDE YOU WANT LESS BOOST.

I will be ordering a BOV and the SMC kit VERY SOON. The ZZP pcm will be in the next 3 months.

[98GREENGLOW]

Also, I dont remember if I posted this or not, but another thing I noticed with my new pully is.......

The old pully would build up to 5-7 psi in first gear and then have a slight lull....Then second gear would come and the boost would build up again. But second gear would normaly be a pound higher than first gear. say 5 psi in first and then 6 psi in second, with third back at 5.

Or say first gear hit 6 psi and 2nd gear hit 7 psi with third back at 5 psi. It was usualy somthing like that. What Im mainly focusing on was the slight lull between first in second gear. The lull was just like the one we have in a NA v6. The typical lull. The only difference with the old pully was that after the lull power would greatly increase thanks to the supercharger which resulted in going from a best NA of 16.1 to a best FI of 15.1.

Now with the new pully there is a HUGE differance. Say I hit 10 pounds in first... second gear will be 9-10 pounds and third gear will go down to 5 pounds. There is no longer a first to second lull. It goes to 10 pounds in first and then seems to instantly be right back at 9-10 pounds in second.

Where there used to be a loss of power between changing gears from the boost having to build back up to 6 pounds in secong gear, there is now just my head snapping at the used to be lull point. It's really hard for me to explain. I guess the 10 pounds just kinda carries over to the next gear in a sense.

Now the lull point seems to be when I hit third gear and the boost drops from 10 psi to 5 psi.

Irf anyone else out there has a 2.8 or so pully as well Id like to here your comments on the first to second gear, before and after 10 pound pully sotp differance when compared to the stock pully. I find the differance amazing.

[Mighty Thor]

I'll be next in line but I wanna get headers first before I update.

I just won a bid on a PD pulley. The same pulley that we have and this guy is using it on his custom made PD on his Saturn.

Check my previous post to see his Saturn. I'm going to use this as a back up. My old pulley will be shim to 2.85.

Do you pics of your current pulley?

I wonder how Rob and Jenn is doing with their pulley?

Green, keep us updated. I really like the feedback your giving us. [img]graemlins/thumbsup.gif[/img]

[Rob 94Hawk 319]

We haven't really had any "updates" per sey, we just moved, so everything automotive is in limbo, but surely as I get the headers back from Jet Hot, and the front suspension finished up we'll get some results flowing.

(and psst.. It's Jana, (just don't want her kicking your *** .. ;) ;) ;) )

-R

[Mighty Thor]

<blockquote>quote:</font><hr>Originally posted by Rob 94Hawk 319:
We haven't really had any "updates" per sey, we just moved, so everything automotive is in limbo, but surely as I get the headers back from Jet Hot, and the front suspension finished up we'll get some results flowing.

(and psst.. It's Jana, (just don't want her kicking your *** .. ;) ;) ;) )

-R<hr></blockquote>

Opps, sorry about the name :D

Offtopic: You sent the headers to Jet Hot? How much are they charging to coat them?

[98GREENGLOW]

Its been 4 days since my last post. So far the 10 pounds of boost is remaining in first and second gear with third gear going down to 5 psi. No slippidge so far.

[98GREENGLOW]

Put on about 60 miles of driving today. Boost was still 10 psi in first and second gear. But third gear just sucks!!!!!!I only get 5 pounds in third gear??????? WHY?????Any other 2.8 pully guys have this problem too??? I mean I know Im being spoiled ( It wasnt long ago we could only get 5 psi in all three gears) BUT STILL..... I mean come on!!!!!!!!!

PICTURE THIS.......

Your sitting there at the light and notice that there are no cars around anywhere......Theres a straight away in front of you. You slam the pedal and BAM!!!!! 10 pounds of boost in first gear(our first gear is pretty decent stock so you can imagine with 10 pounds of boost).

Second gear hits just as hard as first getting to the 10 pound mark with ease. At the end of second gear your doing 60-70 mph.

Then the gears change to third and bam!!!! Adrenaline rush over.... Your at the 70 mph and up zone where our cars REALLY need help and now your ONLY GETTING HALF AS MUCH BOOST AS YOU WERE A SECOND AGO!!!!!!!!

Man those that suck........Im sure that the 5 pounds helps and all, after all I did pull a 207 rwhp in third gear with 4-5 pounds of boost at 95 mph and 4800 rpm's. But With only 7-8 pounds in second gear I dynoed 217 rwhp. You should never dyno higher in second gear than third!!!!!

So there..... Even My dyno confirms how much of a let down my third gear has become.

PLEASE POST AND LET ME KNOW IF THERES A WAY TO FIX MY THIRD GEAR DRAMA