Vacuum leak? Marc has me confused now! - Page 8 - ZR-1 Net Registry Forums

Paul Workman · 05-03-2014

Quote:

Originally Posted by Hib Halverson

The tires were not stock.

They were Goodyear Racing Eagles which were made specifically for the Record Run. I can't remember the size. I'll have to do some digging to see if I still have that information.

And yeah, the 3.07 axle was selected so the car could run 190 mph in fifth gear. As for if that was the optimal ratio? Maybe not but the 3.07 was the tallest ratio available for a D44 in a Corvette. The 2.73 and 2.59 ratios for D36 gearsets.

I'm intrigued by the details, as you seem to be too... (Probably because my favorite TV program was "Mr Wizzard", or maybe because I have a 'low entertainment threshold', or as some have said ... "You're easily amused" - referring to me: never quite sure how to take that

).

But, yeah! Actual tire metrics would be interesting, and I agree the 3.07s were available, perhaps more so than what would be exactly perfect for the "task at hand". Any way ya slice it, the RR was a fascinating moment in automotive history, regardless.

Hib Halverson · 05-12-2014

Since 1990, I've written several articles on the Record Run for different magazines and web sites.

The tires size was not in the last two stories I did, but a search of pre-2000 manuscripts and, finally, found it.

The tires were special race radial race tires done by Goodyear just for that program and the size was 25.5x12.0-17. That tire was used at all four corners on both cars.

weldbead · 05-21-2014

(small)progress update..my fsm's have arrived, i've done a bit of reading there and here..have opened the first connection in the pump suction line (which is just a coupling..why is it there, iwonder..) and with it thumbed off the pump stops instantly, telling me there is a leak downstream which is under the plenum unless its map hose ..so i'm starting to think i'm gotta remove the plenum..
symptomatically :key on engine off pump runs forever..there are times when i punch it and really feel a power surge at 3000 rpm or so, and there are times when i dont..also there are times when i punch it and i think the secondaries are open, and then it peters out and wont get over 5500 rpm so i guess the secondaries have gone closed as vac drops and pump cant keep up..

05-12-2014	#72
Hib Halverson Join Date: Jun 2005 Location: CenCoast California Posts: 899	Re: Vacuum leak? Marc has me confused now! Since 1990, I've written several articles on the Record Run for different magazines and web sites. The tires size was not in the last two stories I did, but a search of pre-2000 manuscripts and, finally, found it. The tires were special race radial race tires done by Goodyear just for that program and the size was 25.5x12.0-17. That tire was used at all four corners on both cars.

05-21-2014	#73
weldbead Join Date: Apr 2014 Location: poughkeepsie ny Posts: 33	Re: Vacuum leak? Marc has me confused now! (small)progress update..my fsm's have arrived, i've done a bit of reading there and here..have opened the first connection in the pump suction line (which is just a coupling..why is it there, iwonder..) and with it thumbed off the pump stops instantly, telling me there is a leak downstream which is under the plenum unless its map hose ..so i'm starting to think i'm gotta remove the plenum.. symptomatically :key on engine off pump runs forever..there are times when i punch it and really feel a power surge at 3000 rpm or so, and there are times when i dont..also there are times when i punch it and i think the secondaries are open, and then it peters out and wont get over 5500 rpm so i guess the secondaries have gone closed as vac drops and pump cant keep up.. Last edited by weldbead; 05-21-2014 at 12:58 PM.