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-   -   My Hemi with new cam to the drags (http://www.jeepgarage.org/f5/my-hemi-with-new-cam-to-the-drags-30397.html)

jeepgcoman 10-31-2011 07:32 PM

My Hemi with new cam to the drags
 
I hurried home from my 1600 mile trip to make the last day of the racing season. Before the trip I installed the FRI Sidewinder cam and 6.1 valvetrain. I did a thread on my trip assessment and fuel economy, and this one will be the drag results. Unfortunately I had to fill the gas tank to get my final mileage figures, plus I didn't have time to strip the WK down to it's "normal" race weight. In addition, my wife was riding shotgun for all of the runs at the track. My normal race weight with about 1/4 tank of fuel, no spare, no mats (cabin and storage), no tool/emergency kit, and no wife sitting beside me is about 5000 lbs. with me in it. Best ET and speed in that configuration (with headers and the stock cam/valvetrain) was 15.18 at 90.17 mph. The density altitude (DA) was ~2400 ft., and track elevation is right at 3000 ft.

This time, configured as I said above (about 400-500 lbs. heavier [~5400-5500 lbs] and about the same DA), my best ET and speed was 15.27 and 89.08 mph. I figure if the, "100 lbs. equals one tenth of a second" hypothesis is true, I can cut at least 4 tenths off the ET and an unknown amount of speed added, when at my normal race configuration. Unfortunately I'll have to wait until spring now. By then I'll hopefully have a CMR tune, a way of opening the exhaust, and a wideband A/F meter to allow me to zero things in a little better. IMO, the cam is a good mod. for the money. That, along with the headers and exhaust have made, by far, the biggest difference of anything I've done.

FlyinRyan 11-01-2011 03:08 PM

Re: My Hemi with new cam to the drags
 
You have a keeper if your wife doesnt mind going racing with you :-D

Looking forward to your results with a CMR tune. I wish more people posted as your kind of attention to detail. What was your DA on this last trip?

jeepgcoman 11-02-2011 12:11 PM

Re: My Hemi with new cam to the drags
 
She's definitely a keeper. This is the first time my wife ever wanted to go to the drags. I was shocked and pleasantly surprised. She seemed like a "fish out of water", but I think, overall, she had a good time. She usually freaks out when I air the WK out on the street, but didn't seem to mind at the track.

The DA at the track was about the same as it was back in April, when I ran with just the headers on.....about 2400 feet. As far as the trip goes, I don't know the DA's, but my guess is that it ranged from ~800-7500 ft. at true altitudes from ~450-7200 feet, over the 11 days. Weather was dry and in the 50-60's, with a storm front coming in on the way back. That's why the 25-30 mph headwinds on the two legs.

FlyinRyan 11-02-2011 02:30 PM

Re: My Hemi with new cam to the drags
 
dragtimes.com

tydallas 11-02-2011 03:33 PM

Re: My Hemi with new cam to the drags
 
You have any videos of the cam installed?

jeepgcoman 11-02-2011 10:08 PM

Re: My Hemi with new cam to the drags
 
Nope. Sorry!

jeepgcoman 11-02-2011 10:22 PM

Re: My Hemi with new cam to the drags
 
Cool site, FlyinRyan. The site says my track is at 2695 feet elevation, but both my GPS's (stock one in WK and portable Garmin) say it's just below 3000 ft. ????? The track folks announce the DA about every hour.

FlyinRyan 11-02-2011 11:06 PM

Re: My Hemi with new cam to the drags
 
Quote:

Originally Posted by jeepgcoman (Post 508284)
Cool site, FlyinRyan. The site says my track is at 2695 feet elevation, but both my GPS's (stock one in WK and portable Garmin) say it's just below 3000 ft. ????? The track folks announce the DA about every hour.

Interesting. Its possible that there is some sort of descrepancy. Ive never had an issue with it, and being a lifelong beach bum, am always near sea level so all I care about is the DA.

Scottina06 11-02-2011 11:54 PM

Re: My Hemi with new cam to the drags
 
I think a cmr and losing the weight will make a big difference. Im not a 1/4 mile racer...so its just an opinion....LOL

jeepgcoman 11-03-2011 07:13 PM

Re: My Hemi with new cam to the drags
 
You're right, Scott, a CMR is definitely in order. The lowest weight I've been able to get so far is 4765 lbs. without me in it. Do you know how hard is it to pull the rear seats? That's probably about the easiest way to lose another 100+ lbs. Any other weight loss suggestions?

Scottina06 11-03-2011 08:13 PM

Re: My Hemi with new cam to the drags
 
rear seats just unbolt...very easy...but have a breaker bar for the bottom bolts.


spare tire
rear cargo floor

jeepgcoman 11-03-2011 10:01 PM

Re: My Hemi with new cam to the drags
 
Thanks!


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