NVRENUF

I am in the process of installing my D1sc. 1989 IROC,5.7 with a stock bottom end (approx 45,000 miles on motor) It came with a 4.25" pulley which I thought was supposed to be 4.75" for 8-10lbs of boost. I phoned ATI back with the supercharger's serial number, they looked it up & said yes,that is correct as they had notes in there system it was being built for a stock bottom end motor. I had done some research previously as well as phoned ATI before I bought it and it seemed to be the consensus that 4.75" pulley gave you 8-10lbs. I would assume ATI is correct in what they say, just would like some other opinions or real world results with a 4.25" pulley. Just don't want anything to go boom!

In the manual it also says to ground both cooling fan relays so both fans run all the time. Is this really necessary? I have a 160 t-stat as well as the cooling fan switch has been changed to come on around 160 so it runs pretty cool. Although it can heat up quick if stuck in traffic on a hot day...(this was before the Procharger & 3 core intercooler) still in the process of install so not sure what the engine & intercooler temps will be.

Thanks for any input/advice

tom86iroc

iTrader: (1)

i have a 3.75 pulley for mine but its for 20+ pounds i haven't installed it yet still waiting on my motor to be finished but for the fans i have the same thing u do with the 160 setup i'm leavin it alone as is but i bought a be cool rad. with fans so that'll keep it nice and cool

mypontiac

I am running a 3.75" pulley with a dual itercooler set up on a 1991 TA. I have a new hypertech sensor that will turn on the secondary fan at 200 F. See Willie's cooling tech information.

In stop and go traffic in Texas I am getting to 220 F.

Steady running less than 200 F.

Cooling always seems to be a problem with our cars!

NVRENUF

So what boost does the 3.75" pulley give you? I'm still trying to find out for sure if a 4.25" pulley is good for 8-10lbs so I don't damage anything.

Anybody running a 4.25" pulley?

tom86iroc

iTrader: (1)

the 3.75 pulley is supposed to give me 20 pounds of boost if the 4.25 is a half inch larger so it will turn slower so you will get less boost but i read in the instructions they recommend only spinnin the supercharger to 5500rpm thats your boost range anything over that it will build more boost so watch out

mypontiac

The boost is going to be a function of your SC Pulley and Crank Pully diameters.

Do a search for threads from Willie.

He had very detailed information on computing boost for different pulley ratios.

When I had my car dynoed top boost was about 15 #.

KS91Z28

4.25" is supposed to be 8 psi on a stock engine with stock heads, cam, and exhaust and a P1SC. The D1SC will make approx. 4 psi more than a P1SC. So, if you're engine and exhaust are completely stock, you'll need a 4.65" pulley to make 8 psi. ATI doesn't make a 4.65" pulley so the next best size is the 4.75" which would get you approx 7 psi.

NVRENUF

Thanks for the info.My engine (5.7L) bottom end is stock & original but it has a crane cam (pn 104124),the original heads have been ported/polished,Superam intake (lower intake as well),Hooker competition headers,custom made 2.5" mandrel bent pipes going into the original 3" pipe,no cat converters,2800 stall converter & Dana 44 rear diff.
Still in the process of installing it....great & complete kit...just some stuff doesn't fit the way they say it should.

Tony89GTA

iTrader: (7)

On my stock engine D1SC 4" pulley gave me 10psi at 5500rpm and from what I remember and seen on these boards 4.25 is for 8 psi. 4.75 is going to give you very low boost and not sure how the one guy figures 3.75 is going to give him 20 psi I can't even get that with my 3.4" pulley, only way is if his crank pulley is friggin huge

NVRENUF

Thanks Tony...I guess I'll find out for sure...if I ever get it finished!

New problem I found out tonight....it appears as though the discharge pipe out of the blower (the blower itself,not the piping) hits the drivers side fender & won't go down far enough for the bolt holes to line up...WTF?
Mine is an 89 IROC, there is a small "bump" right in that area. The main bracket is bolted on correctly (unless loosening the bolts & tweaking a bit would help...I doubt it though)
I have the one larger lower bolt loosely started in it & the top one is about 1/2" - 3/4" away from lining up.
Short of "massaging" that fender down (which I really don't want to do) I'm not sure what else to do....gave up for tonight

Anybody run into that??

gta324

You could loosen the "outlet" house on the procharger and turn it upwards.

/N.

Tony89GTA

iTrader: (7)

yup do that


BTW what do you plan on doing for your extra fuel? You using the fmu or going to do some chip burning?

tom86iroc

iTrader: (1)

thye guy at procharger said i should see 15 to 20 pounds from my d1sc and if you go above their recommended 5500 rev limit you should see more boost i have an 8in crank lmao pulley i havent installed it yet im still waiting on my motor

TraviZ

iTrader: (2)

hey if any of you want a 5.5" pulley, let me know lol, otherwise, sell me your 12-rib 4.0"

Gunner823

iTrader: (2)

The reason Procharger recommends having your fans run all the time is that the intercooler setup almost completey blocks the air pickup for the radiator. I found this to be a HORRIBLE design and have no idea why they did that. A few WOT pulls in warm/hot weather and you are well past 220 degrees. Plan on buying a bigger radiator and larger fans for it at a minimum, or do what a couple of the guys have done and fab your own intercooler setup to the left or right (in some cases, both) of the radiator inlet.

NVRENUF

Ok...got the discharge pipe figured out (I was not aware you could actually move it...was a late night last night working on it, not thinking clearly...lol)

Numerous other little issues keep popping up....surge valve outlet on the rubber air filter adapter appears to have been put in the wrong side when it was made. Discharge rubber elbow(the one that is cut short on one side) & short pipe don't line up/fit that well...seem to be a bit too short & the angles don't want to meet very well with the blower & 90 degree rubber elbow in the drivers fender. Probably just buy some new elbows & cut them to fit better.

After installing the intercooler....yes I see how much it blocks the air. I'll run it the way it is for now & see what happens. Like I said, I have a 160 t-stat & cooling fan switch so we'll see. Maybe try Water Wetter as well.

KS91Z28

You don't have to route the surge valve back to the inlet. It's just set up that way to keep the noise down. Most people just vent the bypass to atmosphere.

I'd highly recommend looking into making your intercooler a front mount setup. I made the change and only needed 1 extra 90 degree elbow. That solved all my cooling issues. These cars depend on that air coming from under the car to keep them cool.

NVRENUF

KS91Z28.....how loud is the surge valve when it's vented to atmosphere as opposed to in the air intake?


How did you make the intercooler a front mount? I have the 3 core...not sure where or how it could be mounted much different?

Thanks

AC

iTrader: (3)

My BOV is vented to atmosphere and when I shift I can hear it over the long tube headers, exhaust, blower, etc. Its actually kinda loud.

KS91Z28

The bypass is somewhat loud, but some people like it that way. Plus it keeps you from recirculating hot air.

I had to cut out a big chunk of the bumper support to mount the intercooler vertically. I've seen some pics here on thirdgen of where some guys fabbed up a bar or brace to go between the bumper supports.

???

iTrader: (5)

I have the d1 non sc and it has an 8in crank and 4 in blower pulls and makes 15 right at 5500rpms. about 18 by 6200ish

Tony89GTA

iTrader: (7)

I had mine like that for a few years and just last summer I hooked it up to the air intake, I like it much better that way keeps it quiet and you can hear the bower whistle for a change.

NVRENUF

I'm not overly concerned with noise...as long as it sounds cool! The car is pretty loud already (no cats, custom y-pipe & flow master) Maybe just try it vented to atmosphere for now & if I don't like it, I can always run the hose up to the intake. I like the idea of not recirculating that hot air back into the intake, I would think that should help a little bit at least. See how it goes I guess, wouldn't mind hearing that & some blower whine as well.....car looks stock & original from the exterior so people might hear it & go WTF?

gta324

If you go to my homepage I have some pictures of my IC install.

I have now changed the RH side, made a hole next to the CC and route the IC piping up through it.

I have no cooling problems, but the weather over here isnt that hot as in some places in US

/N.

Tony89GTA

iTrader: (7)

Thats just it it doesn't sound cool more like a shopvac I cant recall how many times people would ask if there something wrong with my car lol coarse thats when I would stomp on it

OUTATIME GTA

iTrader: (2)

I have an extra 4" 8rib blower pulley if anyone is looking.

Shoot me a PM, thanks.

/end hijack of dead thread