D1sc upsetting garbage
D1sc upsetting garbage
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
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Joined: Aug 1999
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From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Re: D1sc upsetting garbage
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.
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.
Joined: Jul 1999
Posts: 1,992
Likes: 10
From: CT
Car: 1986 Camaro SC
Engine: 305 TPI Procharged D1SC
Transmission: Tremec TKO-600
Axle/Gears: Moser 12 Bolt 3.73 posi
Re: D1sc upsetting garbage
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?
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by 85berlinetta383
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...
Originally Posted by 86Z
do you hear the belt slipping?
Joined: Dec 2000
Posts: 1,954
Likes: 68
From: NC
Car: 1987 Iroc
Engine: 357 Single plane and a Ysi vortech
Transmission: T56
Axle/Gears: 3.50 9"
Re: D1sc upsetting garbage
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!
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!
Joined: Oct 2001
Posts: 12,221
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: D1sc upsetting garbage
Whats the (overlap) cam specs? Do you have you bypass valve setup properly??
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Re: D1sc upsetting garbage
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.
Joined: Oct 2001
Posts: 12,221
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: D1sc upsetting garbage
Something def isnt right. does the blower spin easy by hand??
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by 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...
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...
Last edited by Street Lethal; Jul 6, 2012 at 02:24 PM.
Re: D1sc upsetting garbage
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??
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by 85berlinetta383
258 duration on the intake and 262 on the exhaust.

Forget the pics, lets see some videos....!!!!
Re: D1sc upsetting garbage
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.
Joined: Oct 2001
Posts: 12,221
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: D1sc upsetting garbage
Last edited by TTOP350; Jul 6, 2012 at 11:59 PM.
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From: Boosted Land
Car: 92 Z28
Engine: Boosted LSX
Re: D1sc upsetting garbage
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.
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.
Re: D1sc upsetting garbage
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
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From: Boosted Land
Car: 92 Z28
Engine: Boosted LSX
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by daverr
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.
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.
Joined: May 2008
Posts: 867
Likes: 1
From: pawtucket RI
Car: 1986 iroc
Engine: alum. head 350 supercharged
Transmission: 6speed
Axle/Gears: ford 9in 3.90 35 spline moser axles
Re: D1sc upsetting garbage
can you take a better pic of the supercharger belt routing please how many pullies are on that bracket 2 or 3 ?
Re: D1sc upsetting garbage
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
Joined: Jul 1999
Posts: 12,093
Likes: 126
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Joined: Jul 1999
Posts: 12,093
Likes: 126
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: D1sc upsetting garbage
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.
-- Joe
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: D1sc upsetting garbage
Guys have made 800whp on a D1sc.... 537 is not exceeding the limits
Joined: Jul 1999
Posts: 12,093
Likes: 126
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by Orr89RocZ
Guys have made 800whp on a D1sc.... 537 is not exceeding the limits...
Re: D1sc upsetting garbage
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.
Re: D1sc upsetting garbage
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.
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.
Joined: Jun 2000
Posts: 5,364
Likes: 51
From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: D1sc upsetting garbage
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.
Joined: Jul 1999
Posts: 12,093
Likes: 126
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: D1sc upsetting garbage
I don't think people realize how much air you are moving with these things with only a stock serpentine belt.
-- Joe
Joined: Dec 2000
Posts: 1,954
Likes: 68
From: NC
Car: 1987 Iroc
Engine: 357 Single plane and a Ysi vortech
Transmission: T56
Axle/Gears: 3.50 9"
Re: D1sc upsetting garbage
Aren't you guys worried about all the pressure you're putting on the crank pulley?
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Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Re: D1sc upsetting garbage
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"........
Joined: Dec 2000
Posts: 1,954
Likes: 68
From: NC
Car: 1987 Iroc
Engine: 357 Single plane and a Ysi vortech
Transmission: T56
Axle/Gears: 3.50 9"
Re: D1sc upsetting garbage
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!
Joined: Jul 1999
Posts: 12,093
Likes: 126
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: D1sc upsetting garbage
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.
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.
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From: Utah
Car: 89 RS 89 iroc 87 firebird
Engine: 3.1 Turbo/ 355 twin turbo
Transmission: a4 w/ 4500 stall/ a4 / t5
Axle/Gears: strange s60 /w 3:42's
Re: D1sc upsetting garbage
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.

http://www.atiracing.com/superpulley/index.htm
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Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Re: D1sc upsetting garbage
super pully should fix that problem but it aint cheap,

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

http://www.atiracing.com/superpulley/index.htm
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....
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: D1sc upsetting garbage
but then I had to upgrade to a F2....
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Re: D1sc upsetting garbage
Joined: Jul 2003
Posts: 10,532
Likes: 204
From: NYC / Jersey
Car: 1990 Trans Am GTA
Engine: Turbo 305 w/MS2
Transmission: 700R4
Re: D1sc upsetting garbage
Originally Posted by gta324
Wonder if I need that power on the street...










