new ZR1 owner with a few questions.

[Kevin]

Originally Posted by flyin ryan

i can squeeze the stock duct cold if i want, not a big deal, i'm not saying they are all perfect but i don't believe they are ALL junk either. i'm not one to wave the General's banner, believe me. depends. it's all about draw. where's it drawing from (air cleaner inlet) & how much is the draw (stock LT-5 or modified) . a person can put their hand over the end of a vacuum cleaner & watch the hose snake up on the floor. i'm trying to help DScott600 by keeping his eyes open before he goes & spends his money with both fist's. check it out first, doesn't cost anything . how many cars did we chassis dyno at the PNW gathering a few weeks ago, eleven i believe. inside a building (warm) i didn't see any duct's get yanked off because of the infamous collapsing. again, not saying it's never happened. i see guys overbuild stuff that just doesn't matter all the time. i try to focus my attention (time,effort,money,etc.) on things i KNOW help.

I don't think that all of them are junk, but time + heat = junk. you can see the duct sucking down under load, but since it's kinda hard to drive with the hood up or off, it's nearly impossible to see. Keith's car is a low mile stocker that had a very low base line reading, knowing the car was a low mile 90 we were thinking anything from bad plugs to bad prom to bad injectors. It was mark haibeck who thought to check the duct and sure enough it sucked down like an accordion. If you don't want to believe that the stock duct is not the most high quality piece ever made, so be it. However, since the coplan duct is no longer made (cost all of $25 back when he had them), and the haibeck duct is all of $40 http://www.zr1specialist.com/HAT%20W...ucts/hoops.htm what is the harm in reinforcing it and just making sure? If you drink coffee it is free to reinforce. there are very few parts offered by people like haibeck or coplan for these cars that don't help to improve performance.

[Z51JEFF]

Heres what your looking at.Best thing to do is strip everything from the valley.There is a small drain hole that plugs very easy,it plugs up you get a water cooled starter,not good.[IMG][/IMG][IMG][/IMG]

[cward]

Great pics for what you see under the plenum. Just my $.02 on the vacuum pump: My Z did not have one and ran pretty good. I was told by someone (Graham B) that the Yanks made them put one on for some edge of the envelope cases. I drove my Z pretty hard both on the street and racing of all different kinds and to my knowledge did not suffer from vacuum loss. However, I know many of the Z owners will say they need the pump. Just saying that mine did not. And that old Z of mine did run pretty good for what it had done to it.

Curtis