ZaphodB

Hi!

What method do you other guys that have ATI's use to determine when the belt is properly tensioned, I think I still have some slipping belt problems... And I am not sure of how much I dare to turn up the tensioner.

The manual says that you should be able to twist the belt about 1/4 turn when it's correct, but with how much force?

It sounds like it's slipping when I get about 5 PSI of boost (Max should be 10 PSI for my setup).

Another question is how much did you have to adjust the FMU from maximum rich before getting a good mixture. I know this setting can vary alot between cars, just trying to get an idea about if it's 1/2 turn or 3 turns or whatever?

Willie

iTrader: (1)

What method do you other guys that have ATI's use to determine when the belt is properly tensioned, I think I still have some slipping belt problems... And I am not sure of how much I dare to turn up the tensioner.

I asked the same question after I initially installed my D1SC. It's hard to determine this without actually seeing another car.

The way you can tell if the belt is slipping is to look for very fine black dust on the front of the blower. If you detect any, it's slipping. Also, watch your boost gauge. If boost is created linearly until the shift point, you're probably not slipping. If boost builds to a specific point and stops (while increasing engine revs), it's slipping.

The manual says that you should be able to twist the belt about 1/4 turn when it's correct, but with how much force?

I received a clarification on this from Dorian (ATI). It's not "twisting", it's actually deflection. Take the longest segment of belt between pullies and try to push on it (apply force perpendicular to the belt). You should not be able to "push" it more than 1/4-inch.

It sounds like it's slipping when I get about 5 PSI of boost (Max should be 10 PSI for my setup).

What size pullies do you have? Also, what's your setup? I can compare your figures with mine to aid in determining if you should see more boost.

Another question is how much did you have to adjust the FMU from maximum rich before getting a good mixture.

Sorry, I can't help here. I don't use an FMU.

ZaphodB

I agree hard to find out without another car to compare with....



Then mine is definitevly slipping, going to readjust that belt tomorrow definitively!!!

The manual says that you should be able to twist the belt about 1/4 turn when it's correct, but with how much force?



That was a good explanation all ones I've read so far makes one wonder exactly what they mean one should do to test belt tension.....

It sounds like it's slipping when I get about 5 PSI of boost (Max should be 10 PSI for my setup).



I think I must have 4.00", and I do.... Just checked my papers from ATI, and that was right. Also recall reading 4.00" from the pulley itself....

Willie

iTrader: (1)

I think I must have 4.00", and I do.... Just checked my papers from ATI, and that was right. Also recall reading 4.00" from the pulley itself....

I'm assuming your crank pulley is 8-inches? (I think they're all the same, but not positive.) Also, please tell me a little about your intake mods. Throttle body? Runners? Base? Cam? Heads? The less restrictive, the less boost you'll produce, so I need to know if any of these parts are aftermarket.

Willie

88IROCZ350

I would agree with Willie, you loose boost threw less restrictive things. I run a 12lb pulley and only see 7-8lbs, i have a completely ported and polish intake, heads and full exhaust. so it makes a difference. I have no belt slip and only have about 1/4 inch of play in my belt. good luck and have fun!

ZaphodB

Yes, it's all stock. But I'll head out to the garage and check that belt today and see if it helps.

Most likely it does..... I'll get back to you when I have checked the belt tension out now that I know a bit more on what's safe and whats not

B4Ctom1

I like to use the goodyear "gatorback" and dayco "poly-cog" (not really a cog) belts, because they both have cross cuts on the belt ribs to induce or create pulley traction. I have seen 1 to 2 # more peak boost and more power across the band. I also like to tighten the hell out of them at the track to the point where they are on the verge (but not quite) of doing what I can only explain as "cupping", where the belt actually looks like its trying to fold linearly. that would be too tight. I also take a lesson from the NMRA mustangs that are limited and must use the renegade (vortech YS trim, or procarger D1R) to make power most people would use a bigger head unit to produce. they do it by really spooling up these units. one trick is to use this edelbrock stuff on the belt at the races "it makes a small black streak under your hood but works like the dickens"

83 Crossfire TA

iTrader: (2)

My brother gets a black streak of rubber on the inner fender when his SC belt is slipping (and I mean dark and obvious, it's almost like the tire rubber on the quarters of your car after doing a buch of burnouts).

Some of the local guys use hair spray to get them a little stickier (also works for keeping the rubber elbows assembled in the ducting between the blower and the intake), without the mess of the gasket adhesive.

ZaphodB

Whats a good place to order belts from that will ship overseas?

(That is if I cannot find the gatorbacks anywhere in Sweden where I live....).

Because I think that the belt might be playing tricks on me, I cannot tighten the tensioner much more, yet the belt is slipping and it definitively moves more than 1/4"-1/2" if I press my thumb on the longest stretch of it

B4Ctom1

check with JC whitney?