Jump to content




Photo

New JK Ti22 - evaluation & preliminary testing


  • Please log in to reply
10 replies to this topic

#1 JimF

JimF

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,924 posts
  • Joined: 20-June 07
  • Gender:Male

Posted 04 August 2013 - 01:51 AM

I've gotten some requests from our racers that I evaluate this new body (JK #70812B) for approval. Remembering that our criteria in NorCal is more about parity than ultimate performance, our goal is to not obsolete everything else that we currently use. We do not have an overall length limit (within reason) and our criteria is not a super-fine focus on the model year. Rather we check out how does it look? and....it is it reasonbly competetive or does it blow away everything else?

 

The players, L-R

 

  • New JK TI-22, (shown here w/.230" spoiler)
  • Current "Kirby" TI-22, True Scale, O/S or Red Fox, shown here with a .425" spoiler (max is .500"),
  • Parma Lola T-163. shown here w/..250 spoiler. (max allowed on this body)

 

451bac8f-129a-462c-a6bf-84db031f1a6b_zps

 

The contender: JK #70812B

  • This is a long body @ ~~ 6.75". This is about the same as the Parma Lola and longer than the "Kirby"
  • The side dams are about .300 @ the deepest spot. The "Kirby' is about .190" at the same spot.
  • Front fenders and nose shaping is much better than older JKs as far as fitting the fr. tires and guide.
  • Generally, this body is nicely done and the side to side thickness of the lexan is equal......... :shok:.
  • I would say that the body is long, but the overall appearance is acceptable.
  • Given past experience, I expected this body to outperform the current crop that we allow.

f704e845-4ca5-4f9e-bbf4-2c6f7acd319e_zps

 

Test Car:

 

This is a brand new car with no laps on it. I had no idea how it would go so I purposely chose a pretty mundane motor for the test. No attempt was made to tune either by weight, motor, gear or tire during this test. Car is a JK pan with no side pan hinges (torsion frame). "Straight fork" rails are .062 wire hinged @ front, solid @ rear. WB is 4.093', GL is 1.0" weight as shown is 97.5gr.

 

 

87d33ff9-8d04-4176-9972-4fa7bac9a656_zps

 

 

Test Track: The "Engleclimb" @ Motown Raceway Modesto Ca.

 

This track offers a combination of full punch banks and pretty flat turns. Shown here from the blue-black panel, you see the flattish deadman (foreground) and the flattish "climb" up to the leadon which is tiltled but not really banked. The big turn (bottom bank) under the leadon is banked, very fast and is full punch if your car is right. This turn and the the short chute coming back toward you are key to body stability. Out of view to your right is the high bank and the tucked under "finger turn" which is pretty flat.

 

c1f226bc-9e10-4d8d-a11c-6006aa1b95c8_zps

 

Here's the view from the other end with the full punch bottom bank right in front of you. The flat "climb up" is starting right at the end of the orange driver's station, then the high bank, deadman and finger turn in the distance. Because this high bank is steep and very tight, the body performance when the car comes steeply down toward the deadman should be noted. At the far right.....Mike Colvin (no hair) is guarding the driver's panel.

 

6905ad61-91f6-4d5e-b896-469118b7b449_zps

 

This is the first time I've done a formal body test here at this track. This is a good test because the combination of downforce for the turns and stability in the two banks are a contrast to the advantages of low drag in the straights.

 

The first laps with the new car were with the True Scale TI shown. This is a standby body that always works. After a warm up and getting the feel of the new car, this was run for record. I followed my usual body test criteria and did each test at least twice. Average total laps/body = 30 over 2-3 repeats.

 

True Scale TI-22 Long: (.425" spoiler)

 

  • Best 5 lap run: 5.22, 5.24, 5.24, 5.21, 5.26. Avg of 3 middle = 5.23
  • Hair lap = 5.18
  • This body was loose out of both banks but very good in the flat turns and felt "loose but fast"

 

Parma Lola T163 (.250" spoiler)

 

  • Best 5 lap run: 5.27, 5.22. 5.21, 5.28, 5.25, Avg 3 middle = 5.24
  • Hair Lap 5.20
  • Solid and stable out of both banks. Solid in all turns. Easier to drive than the above, I'm surprised it wasn't faster....but it wasn't.

 

JK TI-22 (1/2" spoiler)

 

  • Best 5 lap run: 5.22, 5.16, 5.15, 5.12, 5.16  Avg 3 middle = 5.15
  • Hair lap: 5.12
  • More solid in banks than either of above. Felt 'planted' and like cut tires would be necessary. Really fast.

 

JK TI-22 (.225" spoiler)

 

  • Best 5 lap run: 5.26, 5.21, 5.20, 5.23, 5.24. Avg 3 middle = 5.23
  • Hair Lap: 5.18
  • Still solid out of both banks. A little more critical than other two but maybe potential for a tiny bit faster.

 

Conclusions to date.

 

General:

  • We have enough bodies on our approved list currently. Probably don't need more.
  • Still........if parity can be found, general availability on JK products is good and consistency is also good.

Model Specific:

  • This new body looks fairly good and is well done.
  • No irritating blobby areas in the pull and thickness is consistent. No paper thin one one side issues.
  • Will be very good on longer chassis....can't say yet on shorter ones.
  • This body will not be approved with 1/2" spoiler.
  • This body may eventually be approved with a shorter spoiler such as the Parma Lola.

I'll have this body with me @ Eddies and we can discuss among the core group there. Meanwhile.....commentary is welcome.


Jim Fowler




#2 Tom Eatherly

Tom Eatherly

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,771 posts
  • Joined: 28-October 11
  • Gender:Male
  • Location:SoCal

Posted 04 August 2013 - 09:49 AM

Nice report and evaluation as usual Jim. Those are some pretty high side dams on the newer Ti-22. I am wondering how that would work on BPR's King. Wish the Parma Lola T163 was still legal with SCRRA; loved that body. But, like you mentioned, we do have enough bodies to play around with. Thanks again.


Tom Eatherly

#3 Tex

Tex

    Grand Champion Poster

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 8,913 posts
  • Joined: 07-July 06
  • Gender:Male
  • Location:Denton, TX

Posted 04 August 2013 - 09:53 AM

I don't keep up enough with other retro organizations; only after reading your evaluation did I realize that y'all limit the spoiler sizes on high-downforce bodies. Is this done to effect parity between the bodies, so that no one body has a distinct advantage over others?


Richard L. Hofer

Remember, two wrongs don't make a right... but three lefts do! Only you're a block over and a block behind.

#4 Alchemist

Alchemist

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,427 posts
  • Joined: 11-November 09
  • Gender:Male
  • Location:Northern CA

Posted 04 August 2013 - 10:58 AM

Excellent writeup Jim!

 

Hope I get a chance to visit with you at Eddies!

 

Ernie


Ernie Layacan

#5 JimF

JimF

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,924 posts
  • Joined: 20-June 07
  • Gender:Male

Posted 04 August 2013 - 11:58 AM

I don't keep up enough with other retro organizations; only after reading your evaluation did I realize that y'all limit the spoiler sizes on high-downforce bodies. Is this done to effect parity between the bodies, so that no one body has a distinct advantage over others?

 

Tex:

 

That's exactly the reason. We don't want one body to dominate the grid or the podium. Limiting the spoiler as we do on the Parma Lola 163, is a good way to do that. At this point, that's the only body where we've made this exception. A few others we have passed up because they were faster and they just didn't look right. This one looks pretty decent.


Jim Fowler

#6 bbr

bbr

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,336 posts
  • Joined: 08-March 12
  • Gender:Male
  • Location:LA

Posted 04 August 2013 - 12:09 PM

Nice report and evaluation as usual Jim. Those are some pretty high side dams on the newer Ti-22. I am wondering how that would work on BPR's King. Wish the Parma Lola T163 was still legal with SCRRA; loved that body. But, like you mentioned, we do have enough bodies to play around with. Thanks again.


But everyone runs a Ti22. I like the idea of a shorter (or longer) spolier as an equalizing factor.
Mike Low
Cry like a baby, drive like a girl, walk like a man.
Give me enough rope and I'll build a fast car... or hang myself?

#7 JimF

JimF

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,924 posts
  • Joined: 20-June 07
  • Gender:Male

Posted 04 August 2013 - 12:21 PM

Tuning the spoiler can be an equalizer in some cases. It could also be a bit of a headache at tech for a larger organization. IAC, So-Cal has a length limit and this body won't make the cut due to that factor.


Jim Fowler

#8 Tim Neja

Tim Neja

    Grand Champion Poster

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 5,516 posts
  • Joined: 11-June 07
  • Gender:Male
  • Location:Orange County

Posted 04 August 2013 - 12:39 PM

It looks like from your report the body was a little faster on this particular track!  The length and the side dams are what I would question. It's that kind of "aero" work that we are trying to avoid to let the chassis be your ultimate advantage--and not some swoopy body!  Great report Jim--- always great to see how complete your analysis are!! :)


She's real fine, my 409!!!

#9 JimF

JimF

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,924 posts
  • Joined: 20-June 07
  • Gender:Male

Posted 04 August 2013 - 02:19 PM

The JK was for sure faster with the 1/2" spoiler but no way I'll approve it that way. With the shorter spoiler it was right with the others. Really, all three bodies were about the same as far as times went so the choice came down to feel and what you like. If I'd had to choose between the three to race on the car shown without adjustment.....it would've been the Lola. Adjusting and tuning might make for a different story but then, that not just analysis of the body and I wanted to stay focused on that.


Jim Fowler

#10 Tex

Tex

    Grand Champion Poster

  • Full Member
  • PipPipPipPipPipPipPipPip
  • 8,913 posts
  • Joined: 07-July 06
  • Gender:Male
  • Location:Denton, TX

Posted 04 August 2013 - 07:06 PM

I appreciate the testing and analysis you've done; I'm too lazy and too far from a track to do anything like that. Knowing that someone has taken the time and put in the effort to correlate and document some empirical data is priceless. Thanks!


Richard L. Hofer

Remember, two wrongs don't make a right... but three lefts do! Only you're a block over and a block behind.

#11 Tom Eatherly

Tom Eatherly

    Checkered Flag in Hand

  • Full Member
  • PipPipPipPipPipPip
  • 1,771 posts
  • Joined: 28-October 11
  • Gender:Male
  • Location:SoCal

Posted 04 August 2013 - 07:55 PM

But everyone runs a Ti22. I like the idea of a shorter (or longer) spolier as an equalizing factor.

Mike, this exactly why I miss the Parma T163. But, the bodies we have work just fine. A little spoiler work and viola! 

Oh, and other things! :)


Tom Eatherly





Electric Dreams Online Shop