Indy-T, Nocones 2026 Challenge Build

Might as well get the ball rolling early on 2026.

My drive to and from the challenge is about 14 hours each way.  That is a lot of time to spend alone in the car, and the mind wanders and comes up with some dumb challenge car ideas.  There were many but as I drove I kept coming back to this one.  This year I decided I want to build a “traditional” hot rod for the challenge.  But since Nocones is building it it will be anything but “Traditional”.  

With the LMP360 the car was built to replace the MG as my track car.  Other than the EJ engine that is a mission it has filled expertly.  But being built as a track car there were limitations imposed on the build that made it more involved and difficult of a build than a pure Challenge car would be.  The build overall would have been easier had I just planned it to have no life beyond the challenge.   I have decided that I want to build this as a dedicated challenge car.  It won’t have much purpose beyond the challenge and I won’t worry about appropriateness for anything else.  If it gets parted out after the challenge that is fine.  

The idea is similar to the “917” challenger that ran years ago.  Put a normal RWD drivetrain directly attached to a rear axle.  I plan to use IRS which will enable the complete removal of the driveshaft shortening the required length some.  I’ve done some measuring and feel a ~110-115” wheelbase will be reasonable to get the job done.   

For the chassis I will fabricate a simple tube style chassis on top of a 1920s Model T chassis.  The Model T chassis will be tapered at the front but otherwise will be fairly “original”. 

The Engine/rear end will be a 1UZ plus 4 speed Auto from a Lexus LS400.  I believe I will be able to attach the transmission output 3 bolt flange directly to the differential input Guibo so the “driveshaft” will simply be a single rubber Guibo.  The suspension arms will be rebuilt and to save a few inches of drivetrain length the hubs/driveshafts will be swept forward 3-6”.   This may be unnecessary though as my math says I need to keep <65” from Axle to pulleys to keep the WB in check and the 1UZ per GRM is ~27” and the Transmission appears to be 29”. 

Front uprights will be Mazda Miata with custom A-arms.  Steering will be??  Pedals and the column will be from the LS400.  The suspension will probably basically borrow the geometry from the LMP360 scalled to work with the uprights.  That suspension worked well in a rear heavy Mid engine car so why reinvent the wheel.   Shocks will be rear motorcycle units at all 4 corners as they really work well for a <2000lb car.  Bellcranks with Pullrods in the front and pushrods in the rear are likely.  

The body will be a narrowed (probably fabricated) T-bucket and your feet will extend through the “firewall” into what aesthetically will be an engine cowl but it will actually be the footwell.  The rollbar side tubes will run all the way to the front and the grille will contain an additional small rollhoop ensuring adequate safety for the driver cell.  

The LS400 radiator will most likely be laid flat in one of the sidepods, and the other sidepod will contain the battery and a small fuel tank.    But I may run the radiator above the trans/diff and leave the sidepods off and just make the entire back look like a stretched out Model T Truck/rumble seat piece.  

Wheels are currently unknown but the goal will be to use Sprint car takeoff tires to have something reasonably sticky but chunky looking.    Possibly 13's in the front and 15s in the rear.  

IF the LS400 stuff does not work for length, I will pivot and use the drivetrain and subframes from the ManX-5 build.  I’m $500 into that chassis and should be able to easily $0 it out on recoup.  It would not be a V8 but then it would also likely weigh less and I would add a turbo.  The Miata engine has proven it is capable of bringing home the Challenge W so I wouldn’t be concerned if the pivot had to be made.  

This one seems extra dumb.  I’m not expecting it to perform super well because it won’t be little.  I estimate the weight will be around 1400lbs but the handling will be “Who knows”.  I’m building this one just for fun so I won’t science it as hard as the LMP360 nor overthink every decision I have to make. 

Expect me to get started in the next few weeks.   This weekend the Panhard Leaves, and the Autobianchi is spoken for so I actually don't have any "on deck" projects right now.   I’m on the hunt for a close to my house Model T frame.  There are like 10 of them for ~$50-100 but all are 2.5+ hours away.    

Adult FSAE!  LOVE IT

In reply to nocones :

Oh man, oh man, oh man!

I swear you're reading my brain on our next build over here!

I suppose our thought is front mid engine. but t bucket body and inboard suspension.

Mr_Asa said:

Adult FSAE!  LOVE IT

It does make me wonder....  If you took the T concept and went completely minimal using the most powerful sport bike motor you can find cheap enough. Chain drive the rear axle.  Perhaps ATV/SxS parts for suspension to save weight.  You could get under 1k lbs with enough attention. 

In reply to Apexcarver :

You aren't wrong.  It's probably true.  Robbie was at like 800lbs with FDat.  

I bet you could fabricobble a passble T-bucket body from a bumper car and/or wheelbarrow

In reply to nocones :

What's going to happen when Stampie pops into this thread and discovers you're going to beat him to the finish line with this idea ?

The LS400 motor only made 250hp IIRC, wouldn't it be simpler/easier/lighter to use a good FWD 4 cyl turbo motor moved to the back? They easily make 250hp and are plentiful (Ford Escape for example, or plenty of GM versions too)

I'm wondering if the long wheelbase as pictured will make it unwieldy on an autocross course?

In reply to MiniDave :

You aren't wrong that a lighter motor or more powerful one could be sourced.  But I've never had a V8 anything, the LS400 stuff is available and cheap.   A transverse drivetrain would allow for a substantially shorter wheelbase, and if I was chasing a win or overall max performance that's what I would use.  But this is just for fun because I want to build it.  I've already won the challenge so I just am in it for the fun of it.  

Also I'm not too concerned about 110-115 because formula continental's are that length and they aren't slow at autox.   Also the material girls car has a 113" wheelbase and was plenty fast at autox.   I'll make sure I have substantial steering lock and it should be okay.   

Hopefully 

In 2025 I'm not sure a LS400 donor is any cheaper than a Chevy LS donor...even a 4.8 makes more power. Clapped out but drivable Tahoes and Yukons can be had for around $1000-1500 around here with title issues or broken A/C. Not that I've been looking or anything...

If it was an LS donor like mashinenbau, suggested would there be away to use a corvette 4l60e and rear diff and just skip the torque tube and have it connect directly to the back of the LS based engine. 
 

From the archives

https://grassrootsmotorsports.com/forum/grm/making-a-v8-mid-engine/125387/page1/

In reply to Somebeach (Forum Supporter) :

That is apparently very possible with GM parts bin stuff (apparently some F-body belhousing and flexplate spacer are the secret pieces).  In fact that may be used in a future build of mine.   I've looked locally and I just don't think I could get the parts and the required controllers under budget.  

As to the availability of cheap HP with the LS engine and the limitations of the 250 flywheel HP 1UZ I think the performance will be as much as it needs to / can be.  I anticipate a weight with driver of 1800lbs.   With 250HP that will be flirting with the 1/4 mile limitations of rollbar in an open top vehicle.  I do not wish to build a full cage for multiple reasons and am satisfied with the potential dynamic score that could be realized with a 12.5 second quarter mile.  

Just to be clear you are all making very sound, logical suggestions, I appreciate them and the interest in the build.  For what I want to do, what I am planning makes sense.  I am under no delusions that it is the "Best" way to build something like this.   Everything you are suggesting is a better way and would make more sense if I was trying to win.   Your suggestions would help anyone else trying to go down this path so feel free to keep posting them.  They do not offend me and I enjoy the conversations.  

I already have a line on the LS400 and it is scrap value cheap.  

The fuel tank in the sidepod scares me.  That plan turned out to be a safety disaster in the 1960s.  

The model T frame use is to meet some rule requirement?   It appears "hats on tube frames are legal" based on '25 results.

Try to not have your feet ahead of front axle centerline.  Safety first.

$2000 Challenge rules state:

Eligible Vehicles:

Any four-wheeled, production-based vehicle that was originally sold as a passenger vehicle is allowed.

Vehicles may either retain production frame rails or equivalent unibody structures, or they may use a tubular frame provided they retain the production body.

If the vehicle uses a tubular frame, then modification of production exterior bodywork is only allowed provided the end result is substantially similar in general appearance to the original vehicle. Sweet box flares are specifically allowed.

If the vehicle retains production frame rails or equivalent unibody structures, then exterior bodywork modification is unlimited, provided no safety rules are violated. Production frame rails or equivalent unibody structures may be modified to alter a vehicle’s wheelbase.

Man, I can't believe that I'm even posting this, because I'm a pretty liberal interpreter of rules.

I'm hung up on "Vehicles may either retain production frame rails..." because how much of the vehicle from which those rails came must also be present? The way I read it, there are two nouns, "vehicle" and "frame rails", and the verb "retain". The vehicle is the retainer of the rails. And to retain them, they must have first been part of it.

OTOH, I want to see where this build goes. nocones is both talented and creative, and I'm sure whatever he brings is gonna rip!

Perhaps frame rails plus grill shell is enough to constitute vehicle?

In reply to nocones :

Sounds good with the scrap price donor Lexus already lined up. 

I am planning to use some C5 donor parts including the 4l60e, c5 rear differential and the torque tube for a challenge idea that I have, so I would be interested in what controllers you mentioned needing?

In my mind I would just use the light switch type set up to control the transmission but I am still trying to figure it all out. 

I don't want to derail your thread, so feel free to respond in my thread on C5 challenge parts thread

In reply to AngryCorvair (Forum Supporter) :

I don't agree.   Previous Challenge winners (Brad, 2021) were a Crown Vic with 0 crown vic bodyshell components.  It was a MODIFIED Crown Vic Frame with a completely custom body, UNLIMITED for Brad meant the entire stock body was LEFT AT HOME.   This years Beetle, and the LMP360 were tubular frames with no chassis or suspension components retained from the registered vehicle.  They really stretch the definition of "modification of production exterior bodywork is only allowed provided the end result is substantially similar in general appearance".   They both retained the OEM greenhouse.  LMP360 retained about 90% by area of it's stock exterior sheetmetal, the Beetle left the fenders and lower 6" of the doors at home.  Which is FINE.  It makes good stories and interesting builds.  This is about filling a magazine with those.  What I am planning is substantially similar to the interpretation of the rules of 3 of the past 5 challenge winners.  

I will be registering a whatever year Model T I determine the frame likely is.  There is a LONG established history of Model T fords being modified for competition by removing the body shell and replacing it with various or no body components.  

As currently defined this meets the rules.  I will be taking a set of Production frame rails from a Model T ford that lived a full and healthy life and RETAINING them for my build.  The bodywork will be modified in an Unlimited way.  Unlimited implies with no restrictions.   The build will be completed entirely within the $2000 challenge budget rules, will have the required NHRA safety equipment for it's performance and therefore will be legal to the currently published rules.   It will also be consistent with the previous "extreme" builds pushing the envelop of what you can do with $2000.  

In reply to nocones :

I agree with your interpretation of the current rules to make this build eligible.  Carry on sir.

Purple Frog said:

The fuel tank in the sidepod scares me.  That plan turned out to be a safety disaster in the 1960s.  

Try to not have your feet ahead of front axle centerline.  Safety first.

The fuel tank will be a small 1 gallon fuel cell.  I will enclose it in some kind of tubular steel for protection.  It may find it's way inside the "chassis" proper.  It's good advice even for non-W2W or street use builds to consider what happens when the car meets something that doesn't move easily.  

Safety will be considered.  I have to drive this and I intend to come home.  I anticipate the pedals will basically be even with the axle centerline.  The tires will extend 12-14" forward of that.  I will also extend the chassis and have substantial chassis members above and in front of the feet.  I am already planning for anti-intrusion bars on the upper A-arms as well as some plates or pockets for the rear upper A-arm mounts to prevent intrusion if wall contact occurred.  

Again thanks for considering things I might not of thought of.  I don't always discuss everything as I think about it, but you bringing it up points out considerations for "extreme" builds like that that others might not consider before they undertake something like this.  And that discussion may make them re-consider or at least inform them of the decision making that goes on behind the scenes.  

Your drawing does illicit model t vibes. Definitely try to find a cowl if you can, they are shockingly narrow already. It'll help with overall definition and identification. 

And I love listening to the engineering and safety discussion. It helps me think differently about what I do. 

In reply to nocones :

You do know you're certifiable, right? But, carry on anyway. This looks like a killer idea!

I am sure you already know about this but here is one of my favorite autocross cars ever.

The builder figured out that using stock frame rails meant a lower minimum weight.  I thought it was an interesting parallel to the stock frame/hat cars that show up for rules reasons at the challenge.  I look forward to your build log.

In reply to nocones :

I'm not saying it's illegal or uncool, I just said why my brain wouldn't have arrived there. I look forward to seeing it evolve!

Is this what you need for steering?

In reply to DrMikeCSI :

Probably something like that.  I'm going to look at Honda center steer racks, or if I can just use one end of a normal rack and have a nice bracket.   There are many center steer kart type racks for cheap on the jungle site..  but I'm not sure those are better then a backyard modified OEM rack would be.    I also may look at a VW beetle steering gear like what is used on Formula Vees