RMC #39 420R Build Thread

[MV8]

No first-hand knowledge of this one, but I'm certain the red cage snaps on and must be removed to do any re pinning. Most connectors are assembled with the pin inserted/removed from the rear instead of the mating surface. Very small allen wrenches are often adequate to release pins. They sell universal key sets on ebay.

 

Draw the connector wiring on paper, take good pictures to show the color coding by each pin, then have no more than two de pinned at a time.

Edited March 29 by MV8

[captain pabst]

The red cage needed to be removed. Then I had a very thin Tweezer for vinyl that I was able to disengage the clip, then pushed it out from the front using a piece of Tig filler wire. Put it all back together and it started right up.

[captain pabst]

Welp. Its all done... I have about 180 miles on it so far. It's a blast. I'll be taking it to a Porsche Club Autocross this weekend.

[pethier]

I seem to remember that PCA does not allow Sevens for big-track events because they consider them open-wheel.

 

No matter.  In your neck of the woods, I expect there are plenty of organizations that do track days.

 

The 420R seems the sweet spot for someone who wants to road-drive and autocross a Seven.  It is legal for SCCA DM class.  It's not going to win Nationals, but may dominate local autocrosses.

 

Transplanting a 2000cc Zetec into my car is what I foresee for me right now.

[CBuff]

 

[captain pabst]

1 hour ago, CBuff said:

 

Date Saved, thanks

[demoray]

If you're looking to autocross, check out the relatively new XU class.   Basically, any street legal car with an automotive engine on street tires (200 tread wear) with very little other performance restrictions.

 

https://cdn.connectsites.net/user_files/scca/downloads/000/074/790/2025 Solo RuleBook March Fastrack.pdf?1741991695

[pethier]

58 minutes ago, demoray said:

If you're looking to autocross, check out the relatively new XU class.   Basically, any street legal car with an automotive engine on street tires (200 tread wear) with very little other performance restrictions.

 

https://cdn.connectsites.net/user_files/scca/downloads/000/074/790/2025 Solo RuleBook March Fastrack.pdf?1741991695

 

Page

 

Xtreme Street Unlimited (XU) High Performance vehicles with minimal restrictions • Eligible vehicles: All production vehicles using an automobile-based engine with seating for 2 or more adults • Windshield wipers are not required • In addition to the allowances earlier in these rules the following aspects of the vehicle are unrestricted:

– Aero components

– Interior modifications

– Weight

Edited April 25 by pethier

[demoray]

XU stands for Xtreme Street Unlimited.

 

Page 270.

 

If you are on Facebook, you can check out the group "SCCA Solo XU Class".  https://facebook.com/groups/392020123979507/

 

The group admin is a former national champion from the WDCR region that drives a Stalker AXR Classic.

[pethier]

57 minutes ago, demoray said:

If you're looking to autocross, check out the relatively new XU class.   Basically, any street legal car with an automotive engine on street tires (200 tread wear) with very little other performance restrictions.

 

https://cdn.connectsites.net/user_files/scca/downloads/000/074/790/2025 Solo RuleBook March Fastrack.pdf?1741991695

"Eligible vehicles: All production vehicles"

 

I think you are going to run into problems with trying to run a Caterham in XU.

 

The EM and DM rules seem to specify that Lotus 7 clones are not production vehicles and are specified as legal in EM and DM by designation.

 

18.1 MODIFIED PRODUCTION-BASED CARS

A. Eligibility

Modified classes D (DM) and E (EM) contain production-based cars which are permitted additional modifications beyond those allowed in Prepared classes CP through FP. Models must meet the requirements of Section 13 (first paragraph),

 

[A Caterham is not going to skate  as a car that was sold for regular street use in the USA]

 

be specifically listed in Appendix A,

 

[It's not]

 

meet the specifications below,

 

[See the "clones"]

 

or be otherwise recognized by the SEB.

 

[Nowhere I can find]

 

2. Clones

Clones/replicas of SCCA®-recognized production cars are permitted to compete in DM and EM provided they comply with the following requirements:

a. They are substantially similar to and recognizable as the original manufactured vehicle on which they are based.

b. Their specifications do not violate any rule stated herein.

c. A clone shall not benefit from kit car manufacturer “running changes” unless those changes have also been submitted and approved.

 

I suggest if you want to continue this discussion, we ask that it be moved to the autocross area of the forum.

 

The bottom line for the author of the thread is that as far as SCCA Solo events are concerned, a 420R is a D-Mod car regardless what kind of tires it wears.  It can be run in DM with trick English hillclimb tyres, but those are not legal on the street in the USA.  Same goes for Hoosier A7 tires, which won't heat in most autocross situations nearly as well as hillclimb tyres.  I recommend Yokohama 052 tires, which will stick when they are cold and then heat nicely.  They are legal for street use (and would be legal in XU, if the car was).  I have Yokohama 052 tires on my Caterham, in a modest size to fit the Prisoner wheels.  

 

 

 

 

[demoray]

Moved the discussion of autocross classes here:

 

https://usa7s.net/ips/topic/15429-new-solo2-classes-for-7s/#comment-148809

[pethier]

2 hours ago, demoray said:

Moved the discussion of autocross classes here:

 

https://usa7s.net/ips/topic/15429-new-solo2-classes-for-7s/#comment-148809

Thanks.  Well, the SCCA moves in mysterious ways.

 

captain pabst, apparently your 420R on Yokohama 052 tires will be welcome in XU!  I'd suggest those tires would be the best one-tire choice for street, autocross, and track.  I'm not a big-track guy, but if you want to go faster on the big tracks, Hoosier A7, but I bet you already know all that.

 

My further comments are at 

https://usa7s.net/ips/topic/15429-new-solo2-classes-for-7s/#comment-148809

 

 

 

 

[captain pabst]

35 minutes ago, pethier said:

captain pabst, apparently your 420R on Yokohama 052 tires will be welcome in XU! 

 

 

I'm on R888R's so not welcome

[pethier]

1 minute ago, captain pabst said:

I'm on R888R's so not welcome

Say hello to D-Mod!

[FE07]

C & C at Hunt Valley. That red car next to yours sure does look familiar.  Sorry I didn't get a chance to talk to you.

 

Jim

[captain pabst]

1 minute ago, FE07 said:

C & C at Hunt Valley.

Will catch up to you next time.

[pethier]

On 10/9/2024 at 9:47 AM, JohnCh said:

Yes, that transmission tunnel is tight.  Given production tolerances, some transmissions rest against the side of the tunnel requiring extra effort to create a gap.  Any updates from Caterham on your missing roll cage?  

From other discussions I have read that Caterham is mounting the Duratec engine two inches aft of where they used to mount Ford engines.