Rear Body Section for Gen3

Check out the latest version of the Spec Racer! LBoth ligher weight and more powerful!!! Available soon, racing in 2015!
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 725
Joined: Wed Nov 30, 2011 1:03 am

Chassis:
828
Facebook Page:
http://www.facebook.com/#!/denny.stripling
PostPosted: Fri May 05, 2017 5:27 pm
I just cut my new tail last weekend (if you haven't seen why, you missed some jackassery on my part at CoTA #mybad). I recommend you go with the 2018 specs per the GCR. I considered leaving my tail uncut in back for this season as it's legal but it definitely contacted the muffler and my header/muffler is already further inboard than most. The 4" cut removed the portion that contacted the muffler plus now I know I'm legal for 2018 and beyond. At that point your only decision is how high to cut (I believe the range is 4"-8" but consult the GCR).
It's a pain to re-cut (heaven forbid fill in) the tail for next season. If you have a Gen2 tail with the scoop, I'd personally fill it in as it serves no function but to add drag to a Gen3... plus it won't be legal in 2018 as I read the rules.
____________
Bay 12, please.
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 725
Joined: Wed Nov 30, 2011 1:03 am

Chassis:
828
Facebook Page:
http://www.facebook.com/#!/denny.stripling
PostPosted: Fri May 05, 2017 5:30 pm
Now that I re-read your post, Bruce, I'm pretty certain I didn't answer your question (#againmybad). :)
I went with 4" but I don't have any specific explanation as to why other than I think it looks better.
Going 8" would save more weight in the tail I guess...
____________
Bay 12, please.

Ready to Write a Book
Ready to Write a Book
Posts: 83
Joined: Thu Jul 25, 2013 10:52 pm
PostPosted: Sun May 14, 2017 4:19 pm
How about some pictures?
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 278
Joined: Thu Feb 23, 2012 3:35 pm
Location: Ohio
Chassis:
244
PostPosted: Tue May 16, 2017 9:58 pm
Using the dimensions specified on my full tail for my Gen3, I decided to cut out to the 8" dimension and that took about 2 lbs out of my tail weight.
Bob: stand your tail on its front end and measure outside to outside to find your centerline. Then measure for each half of the 62.5" and mark a vertical line on each end at the bottom of the tail. The 4" minimum to 8" max is up to you measured from the approx bottom of the back of your tail. I used a spray can plastic lid to approximate the 1" radius in each corner.
The 8" is what I used to have when I had a scooped tail on my Gen2 and I liked the more open look.
Hope that helps.
Mark Fick

Ready to Write a Book
Ready to Write a Book
Posts: 84
Joined: Fri Sep 21, 2012 10:37 am
PostPosted: Fri Aug 18, 2017 5:32 pm
I keep reading about the '2018 specs', yet I can't find them anywhere. All I can find is that the CGR says "Tail: can be used in any legal SRF configuration until the start of the 2018 competition season. Final SRF3 configuration: For muffler clearance, a minimum 4” cut and a maximum of 8” X 62.5 +/- .500” with a 1” radius in the upper corners. Measured from the bottom up and centered left to right. No Roush Exhaust Scoop."

I have a brand new tail and I need to make the muffler clearance cut. I know that, for the Runoffs, a cut between 4" and 8" will be legal. But if I'm going to make the cut, I'd rather only do it once. To make that decision, it would be nice to know what the 2018 regulations are. For 2018, is the spec still the 4" - 8" and the decision is left to us between those measurements?

Anyone have a clue?
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 670
Joined: Wed Nov 30, 2011 12:21 am

Chassis:
595
PostPosted: Sat Aug 19, 2017 2:58 pm
I would consider the wording "Final SRF3 configuration " to be ...
Bob Breton - SRF 51 - San Francisco Region
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 278
Joined: Thu Feb 23, 2012 3:35 pm
Location: Ohio
Chassis:
244
PostPosted: Sat Aug 19, 2017 6:13 pm
Joel, et.al.: I cannot recall exactly when the 2018 specs came out from Mike Davies, but I recall the following:
1. No scoop on the Gen3 tail after 2017 season. 1/1/18 no scoop. Most of us do not have them anymore anyway.
2. The tail cutout in the rear has to be a minimum of 4" and up to 8" with the side dimensions along with the 1" radius you stated so I won't repeat them here. The 8" allowance was for the cutout when the scoop was installed on our tails and Mike didn't see an easy way to fill that part in when the scoop was removed. Most of the Gen3 guys are cutting out for 4" that have full tails to begin with.

I am not sure what happens to the Gen2 cars regionally, but if they compete as an SRF in 2018, I am assuming no scoop also. Mike wanted the scoop to go away after 2017.
If anyone has a reason to mount a scoop on their garage wall, I have some used ones in stock ... :D

Hope this thread helps.
Mark Fick

Ready to Write a Book
Ready to Write a Book
Posts: 84
Joined: Fri Sep 21, 2012 10:37 am
PostPosted: Mon Aug 21, 2017 4:34 pm
Mark - That helps! I cut the bottom of my tail section this weekend and opted for the 4" cut that most everyone seems to be doing. Right or wrong, that will be my configuration for the Runoffs and the 2018 season.

Forum Hermit
Forum Hermit
Posts: 100
Joined: Mon Dec 12, 2011 1:10 pm
Location: Huntsville, AL
PostPosted: Mon Aug 21, 2017 5:05 pm
Why would you change the standard Gen2 SRF rules when the reason we don't upgrade is we are cheap. Last thing I need is a forced $1500 upgrade to a new tail.
Bruce Funderburg
SEDiv SRF #4
User avatar
Needs a Life!!!
Needs a Life!!!
Posts: 670
Joined: Wed Nov 30, 2011 12:21 am

Chassis:
595
PostPosted: Mon Aug 21, 2017 5:24 pm
Since the scoop serves a cooling purpose in the Gen2 and it doesn't have a beneficial effect otherwise (just more drag), I don't see a major reason to outlaw it. Worse case scenario is to remove the scoop and fill in the areas, retaining the standard 8" cutout. Hopefully that won't cost $1,500!

For those with a "Renault" configuration without the scoop, again, I don't see a reason in mandating the cutout since that came about strictly for the Gen3 to provide tailpipe/muffler clearance. Again, no advantage for SRF2 to retain the stock rear section since it is extra weight and drag vs. have a cutout. At least adding a cutout would get rid of weight (and potentially drag), hopefully for less than $1,500, too! ;)
Bob Breton - SRF 51 - San Francisco Region
PreviousNext

Return to Spec Racer Gen3

Who is online

Users browsing this forum: No registered users and 2 guests