RealQuick

Mitchell,

Any updates on the car?

Ralls

Hey Jon. The car is finished...sorta. I signed up for the LTx Shootout this year but it got down to last couple weeks and I couldn't find someone soon enough to tune the car. Well actually I did get it tuned but something was acting up so we quit without really getting anywhere. Between like 4,600-4,800rpm the engine would bog down then pick back up after that. We turned off the meth injection but that wasn't causing it. Then lowered the boost to 10lbs. Still doing it so we pretty much left like that making around 450hp. Got it home and discovered a torn vacuum line. Not sure if that was the cause. At this time, the Shootout was in a week and I couldn't get it re-tuned in time. I drove it 700 miles to the Shootout and back. Didn't race though. I'm just happy it made it there in one piece. This new motor way better than the last. No blow-by or pissing oil everywhere.

I'll try to get it tuned again this week. I'm not so much in a hurry as before.

ramair96ws6

From the dead.

I used this setup and it works perfect! I put the pump where the AC was and left the Alt in the stock location. Everything fits like factory.

Thanks
Steve

Ralls

Sweet man. Mine is still working good too. Did you have any trouble routing the intake/exhaust lines to the pump? Were you able to keep the stock belt tensioner? I'd like to see some pictures if you have any.

ramair96ws6

Nope all the lines went on without any issue and I used all 12AN parts. I was able to use the stock length belt and tensioner. I will have to take a few pictures tonight and host them up. I wish I would have taken a few before I put it all together. The pump is almost invisible down there...I didn%u2019t change the Balancer as the cost to change it and all of the blower parts really outweighed the cost if this pump fails. I spoke to GZ and they said it should hold up find even spinning it to almost 7k rpms.

Ralls

Awesome. That's cool you too were able to use the same length belt. Makes it a little easier to get replacements. Have you drove it yet? I'm curious how much vacuum your crankcase is under compared to mine.

ramair96ws6

I haven’t drove the car yet. It is a little bit a way from street able. How did you measure the vacuum and what are you seeing?

Ralls

I'm getting around 9" of vacuum. GZ says the pump will do more, but that's all I can get out of it. I couldn't find any leaky seals that would lower the vacuum. 9" is a good amount so no big deal. That's why I'm curious what you would make.

The way I hooked up my vacuum gauge to the crankcase was kind of a pain. I tapped threads into the large PCV port on the stock intake manifold for a large allen head plug. Then drilled and tapped the plug with a smaller nipple fitting for the vacuum line.

mzgp5x

App... LT1 383 97SS MM6 F1A.

I did a GZ vac pump mod 2+ years ago. Different mount. I run about 1/3 atm vac @ 6K rpm with the crank pulley setup. I had some clearance problems with the catch tank/ receiver. I fabbed my own cintrifugal type with a return line to lube the vanes on a VP103 pump. I fits forward inside the bumper out of the way.

It made a big improvement in cylinder pressure and blow-by control. The rings seal better than ever as there is much less leak loss around the ring pack during start-up. I have had starter problems due to this. I shall make the final starter circuit fix this Winter. The std Chevy circuit does not work with the VATS module control of the ground, and, you may have to go with a high torque starter. Summit sells some good starters.

Oil is much cleaner with the Vac pump mod. Hope this helps.
B.

streetbad

mzgp5x what pulleys do you run on your GZ pump?

87Aerocoupe

Has anyone figured out a way to use this vac pump and keep the a/c, my setup is a 97 SS Camaro with all forged 383, Ai TF215s', Ai cam and an F1A?