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Old 09-12-2017   #11
Mystic ZR-1
 
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Join Date: Jan 2010
Location: Mystic CT
Posts: 2,632
Default Re: Top speed in 1ST gear for stock Z?

See Ronstar post above.
Makes no difference, even if it takes a week to get there.
2nd gear's my favorite ~0 to 85ish w/o shifting!!!
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Old 09-12-2017   #12
rush91
 
Join Date: Feb 2016
Location: Carterville Illinois
Posts: 849
Default Re: Top speed in 1ST gear for stock Z?

Quote:
Originally Posted by Paul Workman View Post
Just a "SWAG", and I hate doing that as a rule, BUT those symptoms (runs out of steam at 5000 rpm) are classic "NO SECONDARIES" scenario, OR the accordion hose between the air filter box and the plenum is collapsing (which is what mine was doing when I had that exact problem).

Do you have the stock hose? If so, Marc can provide you with some hoops to insert in there to keep it from collapsing. Easy fix (if that is the issue).

And, if the hose isn't collapsing, then there's fuel pressure and Secondary Port Throttles (SPT) operation to verify.

You're in FBI country, so some of the best gurus of the ZR-1 are not far away! But, the "group" mainly resides in the Chicagoland area. But, IIRC, you're near Marion, IL, yes?

If so, and you want to drive up to Custer Park, I've got everything on hand to trouble shoot/assess the situation and either fix it or at least put you in the right direction.

PM me and we can hook up.

BTW, what year is your ZR-1?

Paul.

P.S:

If you can fashion a metal sleeve to fit inside that accordion hose, it might solve your problem and save you the trip... Just sayin.
My Z is a 1991, about 49,000 miles on her. I have wondered about the air duct for sometime now. It's original, and it could be collasping under load. And for $30 bucks I think, Marc's solution is nice. So are those silicone ducts Jerry has for sale, very nice......

And I live in Carterville, which is about 10 minutes from Marion. I keep my Z in Marion, which is 30 seconds from interstate 57 lol. I will take you up on that offer!! I'd love to truly trouble shoot this car. I do wish I lived closer to FBI land, I'm about 5 hours from Chicago.

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Old 09-12-2017   #13
ssrszz4
 
Join Date: Jan 2017
Location: US
Posts: 233
Default Re: Top speed in 1ST gear for stock Z?

I believe what causes the bellows to start collapsing is a plugged air filter. Once they start collapsing they of course weaken and it just gets worse.

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Old 09-12-2017   #14
efnfast
 
Join Date: Nov 2011
Location: Dunbarton NH
Posts: 7,446
Default Re: Top speed in 1ST gear for stock Z?

RPM and speed are all mechanical. Power doesn't factor into it. Tach not reading right or gears have been changed.
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Old 09-12-2017   #15
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,701
Default Re: Top speed in 1ST gear for stock Z?

If u can datalog, u can read correct RPM directly from ECM.
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Old 09-12-2017   #16
Paul Workman
 
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Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
Default Re: Top speed in 1ST gear for stock Z?

Quote:
Originally Posted by rush91 View Post
My Z is a 1991, about 49,000 miles on her. I have wondered about the air duct for sometime now. It's original, and it could be collasping under load. And for $30 bucks I think, Marc's solution is nice. So are those silicone ducts Jerry has for sale, very nice......

And I live in Carterville, which is about 10 minutes from Marion. I keep my Z in Marion, which is 30 seconds from interstate 57 lol. I will take you up on that offer!! I'd love to truly trouble shoot this car. I do wish I lived closer to FBI land, I'm about 5 hours from Chicago.

Sent from my XT1585 using ZR-1 Net Registry mobile app
I'm "south of I-80", east of Kankakee about 20 miles; a little bit over 4 hrs (is all). Given some notice and we could see who we could entice from Chicagoland to join us too!

It might be a good idea to nab a plenum gasket set too ahead of time - just in case. We can assess what next steps need to be/ parts needed etc, and go from there. And, we can feed you a fine meal too, time permitting!
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