CLASS RACER FORUM - wrong spec submitted by MOPAR

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Re: wrong spec submitted by MOPAR

This is a pretty lame excuse about the converting from Metric. There are computer programs and calcs to do this if this was problem it's just sloppy work by the people doing the work. Look at the Ford problems 3 years in a row at US Nationals, now Mopar.
Since they are built to Metric measurement that's what should be submitted and let NHRA do conversion, better yet NHRA should do measuring in metric problem solved.

Quote:

Originally Posted by dwydendorf (Post 324787)

I was involved with the teardown of the Fords last year and in their case, part of the problem involves the way the specs are sent to NHRA in the 21st century. Now all the automakers have converted to metric (remember that?) and all the specs have to be converted to Inches. Stop and think about how much effort has to go into sending in the tech specs now, as opposed to how it used to be. It is not hard to understand why the car manufacturers don't send in all the specs for every car they make. Sometimes conversions are miscalculated and the problems begin. Most of the racers with the new cars are not doing their own engine work, so it is easy to understand how problems can compound.. How about giving everyone involved a little slack. It is not as simple nowadays to just send NHRA the specs as it used to be. Maybe it is time for NHRA tech to get in the 21st century and use the new metric specs. How many would like to see this?

Re: wrong spec submitted by MOPAR

Use 25.4 to convert.

Re: wrong spec submitted by MOPAR

Quote:

Originally Posted by BlueOval Ralph (Post 325250)

It's not just the spec that is the problem, its the way NHRA measures parts versus the way the OEM's measure parts. For instance, NHRA has a plus .005 and minus.015 spec on valves size and now the OEM'S have to convert their specs to fit NHRA's specs. Do you honestly think that the OEM's use Plus.005 and Minus .015 as their factory specs? In Ford's case in 2009 and 2011 U.S. Nationals, the mean of the spec wasn't right causing the measured part to be out of NHRA'S spec When was the last time that you guys were in teardown with your own stuff?. I measure my parts pretty close, but one time when I went through teardown at the U.S. Nationals, one of my valves was right on the low limit and I didn't think I was even that close before it was measured. Remember that NHRA uses a Dial or digital caliper to measure your parts with and they just zero it out first before they check your parts. You better hope that your parts measure to the way they are measuring them. The late Division 3 tech director Marty Barrett told a buddy of mine once that their methods don't have to be right, they just have to be official. If you have to go through teardown you better hope that your work isn't sloppy also.

Re: wrong spec submitted by MOPAR

so how do we handle the problem????????????????????????

Re: wrong spec submitted by MOPAR

Quote:

Originally Posted by Mickey Whaley (Post 325348)

so how do we handle the problem????????????????????????

There shouldn't be a problem.

It should be simple the OEM has a spec of what dia the valve is supposed to be just like always. say it is 52.832mm (2.08 inches) so its largest dia could be 52.959 dia .127mm (same as .005)+ dia. Its smallest would be 52.451 dia -.381mm (same as the .015). Now there tolerance may not match NHRA's But then it probably never has. These are the same measurements they have used for years.
Now if these motors were built before any specs were out there how where they ever built and how could they be raced with out having specs in the NHRA guide? Seems like a lot of iffy things go on with the new cars. Every time they are found illegal it is always a wrong specs issue.