85berlinetta383

Got my camaro all together, took it to the dyno 2 hours out of town and had nothing but belt slipping issues. I'm running anywhere from 4.25", 4", 3.85" with the 7.65" crank pulley. My belt was a gatorback and was so tight it took two of us to get the blower pully onto the shaft. maxed the tensioner and made a pull... made 4 lbs of boost, what a joke. tried the smaller pullies with about 200$ worth of belts and actually made less boost since it was slipping so bad. i realize I have a bigger engine than stock 403ci afr heads, 675. lift solid cam. but i was expecting atleast 8-10 lbs. what can I do besides smash this setup with a hammer and go turbo.... on a posative note i made 200 more rwhp with 4 lbs of boost than with 0 lbs of boost. ill post pics tomorrow.... half of our setup has been changed from stock since it was a used kit and we made due with what we had. thanks gang

gta324

Dont know what your setup looks like since its not 100% procharger.
I also have had major slippage problems.

Added a spring loaded tensioner ( search) got alot better! But the whole thing was flexing under load, so I bent and broke the long bolts that attach the bracket to heads. SO I made a new construction and what a diffrence! But still had some small slippage att 5500-6500 rpm maybe with a 3.45"pulley so now I have made a new bracket, not tested yet...I think I added spme problems along with high stall speed...............I also managed to break the crank key with this setup so its good!

read
https://www.thirdgen.org/forums/fabr...r-bracket.html

goog luck!

/N.

86Z

iTrader: (4)

with that size motor those are some big pulleys, i'm using a 3.7" pulley on my 305 make 14#'s do you hear the belt slipping? black shavings?

Street Lethal

iTrader: (16)

I'd be more worried about other noises now, like his front main bearings...

NufNuffZ28

iTrader: (10)

Can you show us some pictures?

There are plenty of supercharged set ups on here that work, so I think we can get you figured out!

Where you putting the pulley on AFTER the belt was on the pulley?

I have a cogged setup on my Iroc, so no slip issues, but did have problems with head unit flex, so I braced it off of the STB and the body. Haven't thrown a belt since!

TTOP350

iTrader: (8)

Whats the (overlap) cam specs? Do you have you bypass valve setup properly??

Street Lethal

iTrader: (16)

If it's the cam in his signature, the XE294 has 33º degrees overlap...

85berlinetta383

sorry guys, i'm heading back to the shop in an hour I'll get pics. I have to update my sig, thats my old 383 setup. New motor is 110 lobe seperation 675" lift 9.8-1comp. Shp block, callies crank and rods. I hear no belt slipping, but on the dyno the charger pully was about to have a nuclear meltdown.. 230 degrees F vs 140 degrees F for the crank pully. The dyno guy was in shock as i literally made next to no boost for the first few runs. were gonna try a different belt today, maybe one with no "gator back" I have read about these green industrial belts. Willing to try anything. I had a friend hold his hand over the dump valve and as soon as I got on the throttle it stopped bleeding the air off. I did manage to shatter my 9" diff into a pile of pieces at the track when we got the belt to slip a bit less, don't know exact boost numbers as I was trying to keep the car straight. Sprayed some hair spray on the pulley to attempt some belt traction, it felt like it was pulling hard before the rear end let go at the 80' mark.

TTOP350

iTrader: (8)

Something def isnt right. does the blower spin easy by hand??

Street Lethal

iTrader: (16)

Monster cam, what are the rest of the specs? Aside from the overlap which we'll know once the specs are posted, did you check to see if you are lifting a head? An additional 200-RWHP at only 4-psi is freaking unbelievable... almost literally. Please post pics asap.

Edit: If your making that much additional RWHP at only 4-psi, it sounds like your supercharger may not be keeping up with your engine's demand. I just remembered that your running a D1SC, you may need to upgrade to an F-series because from what I am reading your engine sounds like it will inhale that supercharger right off of the bracket all on its own...

85berlinetta383

258 duration on the intake and 262 on the exhaust. I'm having trouble posting pics, anyone have an email address I can send the pics to so they can post them For me??

Street Lethal

iTrader: (16)

@ 0.050" ????

Forget the pics, lets see some videos....!!!!

FSTFBDY

iTrader: (33)

Deff. sounds like its time for a F series ProCharger setup.

85berlinetta383

I know the D series is way undersized but I stared at it for 3 years with dreams of going blow through carb 383. I finally needed a rebuild so I told my engine builder I want a healthy motor that I can throw a bit of boost at. I would go cogged setup but don't wanna shear my crank snout with 3 passes and 4 hours of total run time.

85berlinetta383

I'll Email pics and a video of initial start up if someone sends me one. I'm at the cabin and only have my I phone.... Can't post pics.

TTOP350

iTrader: (8)

Thas a tad smaller than my cam but I'm NA. I wish I went a bit bigger..

FSTFBDY

iTrader: (33)

email me all ya got at FSTFBDY@GMAIL.COM i'll post it for ya

daverr

iTrader: (1)

I would try another boost gauge and check the line from the
Boost gauge to the engine for proper routing or if it is broken
Or plugged up. Where are you getting the boost signal from the engine??
I think your making more than 4lbs of boost to get 200 more hp.

DIGGLER

iTrader: (1)

yup 200hp doesnt sound like 4#.

prossi

how much RWHP did it make with no boost?

85berlinetta383

340 rwhp with no boost very little timing and a bit rich, with 4 lbs on the dyno operators that's 5 lbs on mine for a split second I made 537 rwhp

FSTFBDY

iTrader: (33)

Here are the pic's for you.

FSTFBDY

iTrader: (33)

more

FSTFBDY

iTrader: (33)

3 more.

FSTFBDY

iTrader: (33)

last set.

Will upload the video to youtube for ya

FSTFBDY

iTrader: (33)

video
http://youtu.be/Z3obpsbd92E

Street Lethal

iTrader: (16)

Dave is definitely onto something here, where is the boost signal hooked up? If your making 340-RWHP naturally aspirated, and 537-RWHP at only 4-psi, your boost pressure gauge might be showing a false number due to a defect somewhere. 15-psi is normally the target boost pressure where horsepower is essentially doubled (in ideal conditions, of course), so at 7.5-psi your horsepower should be somewhere around 510-RWHP. It sounds like the D1SC was huffing closer to 8.5-psi during those pulls, but your gauge is reading wrong...

tom86iroc

iTrader: (1)

can you take a better pic of the supercharger belt routing please how many pullies are on that bracket 2 or 3 ?

85berlinetta383

There are 2 pullies plus the tensioner, one is by the crank pulley and helps the belt have major contact on that pully.... Stock location I believe. There's one ontop of the belt to the left of where the tensioner goes and then there's the tensioner location, slotted no real choice where it goes. On the way home now I'll post more pics as soon as I'm back

anesthes

iTrader: (12)

4 psi on his motor might be 26 psi on a stock 305.

-- Joe

anesthes

iTrader: (12)

The d series is not undersized for your setup. i'd probably have gone with a different cam. My 412" AFR headed SBC using the NX276HR cam with a P1SC.

-- Joe

Orr89RocZ

iTrader: (20)

Guys have made 800whp on a D1sc.... 537 is not exceeding the limits

anesthes

iTrader: (12)

Agreed. I suspect belt slippage and possibly boost blowing out the exhaust due to the cam.

-- Joe

Street Lethal

iTrader: (16)

The D1SC would be exceeding the limits if he really is making an additional 200-RWHP at only 4-psi, because that would mean his engine is making around 800-RWHP naturally aspirated. But now that he has confirmed 340-RWHP naturally aspirated, then there is a problem with the gauge, there has to be, because he won't make 200-RWHP at only 4-psi while making 340-RWHP naturally aspirated...

85berlinetta383

Well a couple hours ago I got home from the shop, got a belt 1.5" smaller overall to fit onto the supercharger. Had to remove idlers and use a pry bar to get the blower pully on. I am now using the stock ati crank pully and 3.85" blower pully. The belt is guitar string tight and has alot of adjustment left on the tensioner. I'm running a 64.5" gatorback belt, does the pattern on the gatorback belt( diagonal slits ) not allow for less contact surface than a complete belt? if this doesent work I'm going with a cogged setup. As far as comparing numbers with my NA Horsepower above vs 4-5 lbs boost I really don't know how accurate that 340 horse NA number is. I didn't pull the motor very high. 340 NA sounds low as the old 383 setup made 500 hp on an engine dyno, my engine builder of this 403CI said I should easily be around 550-575hp NA.

prossi

then i think you need to get an accurate NA baseline to start with, your saying the HP went up 200 when you boosted it to 4psi but, going on what you just said above you dont even know for certin how much power it made NA. Kind of sounds to me your chasing your tail a little bit. or your not getting the correct guidance from your engine builder.

Twin_Turbo

iTrader: (25)

I had to use a belt that is so tight I need to remove 1 of the idlers to even be able to get it on there. Then the bracket flex is another problem. This is my solution.

anesthes

iTrader: (12)

I have a third-party bracket, with some of those bars as well. The guy I got it from said he had some bracket flex issues and tossing belts.

I don't think people realize how much air you are moving with these things with only a stock serpentine belt.

-- Joe

NufNuffZ28

iTrader: (10)

Aren't you guys worried about all the pressure you're putting on the crank pulley?

gta324

yes thats the main reason I'm thiking of buildning a crank support or go turbo But since I have a 12rib there isnt much roon in front of crank pulley.......

I broke my woodruff key last year, so the torque that the supercharger place on the crank/damper is high Now I have some sort of "dual keys" in it, see if it holds better.

The stress on the front bearing: I pulled my engine this winter and the front bearing looked ok after 7 years with procharger, but then I have a spring loaded tensioner on it so the belt is not "overtight"........

NufNuffZ28

iTrader: (10)

I have a cogged setup so it doesn't have to be as tight, BUT the bad part is that it makes it more unforgiving. I threw a couple belts and broke a key before I braced the SC due to flex and movement. Now I seem to have got it licked. The stock bracket is very inadequate for a cogged Ysi!

anesthes

iTrader: (12)

Not really. $800 forged crank. If the snout breaks off with that much belt pressure, that would be pretty darn lame.

-- Joe

vwdave

Ive asked procharger about this same concern when I put a P1SC on a F150. What they were saying is the stress on the front bearing is nominal, the reason cranks break the snouts is when you lift off the throttle and the force sheers the crank snout the other direction, snapping it off.

It would throw the belts off because when I would go WOT. The belt would go near the edge of the pulley and throw. Shimmed the bottom outwards and now the belt walks inwards slightly. It would also slip like crazy, only way I could get it to stop is to tighten the living hell out of it. I would have the tensioner loosened all the way, start the belt as much as I could by hand, and bump the starter. Then tighten.

DIGGLER

iTrader: (1)

if you need to run insane belt tension, i would use one of the crank to supercharger pulley relief arms. kurgan sells one.

project89

iTrader: (1)

super pully should fix that problem but it aint cheap,

http://www.atiracing.com/superpulley/index.htm

NufNuffZ28

iTrader: (10)

They are awesome. I couldn't find one for my Ysi though

gta324

The problem with that is that is a big pulley, and to make the supersharger spin fast the crank pulley would be hugh! I was thinking of going that route but then I had to upgrade to a F2....

Orr89RocZ

iTrader: (20)

Seems like a positive to me

gta324

Wonder if I need that power on the street

it involves a new bracket and a cog setup and really dont have that money now since we planning on a another US trip next spring.. But maybe something to take in the suitcase home

Street Lethal

iTrader: (16)

Why the hell not...