Future of KOH 4400 chassis/car development?

[AgitatedPancake]

While we're on the topic of SxS differentials, can I just say how much of a mind fawk it was to discover that the ring gear/carrier of razr differentials rides entirely on plastic(?) bushings and thrust surfaces? The entire back side of the ring gear glides along a circular thrust surface inside the case, inherently using the case itself for rigidity similar to a load bolt. The axle shafts themselves have bearings after the hilliard clutch, but that's not directly supporting the ring gear as I understand it.

Just interesting to have my eyes opened to other ways of accomplishing things

Super long video, but he pops the cover right around 4:30 and you can see the thrust surfaces

 

[SLOWPOKE693]

That's weird. My front and rear diff both have bearings. Rear is a spool and the front is a bolt together limited slip that uses the ring gear as part of the case instead of it bolting on like a conventional diff.

 

[CarterKraft]

How did the supercharged 427 do in Blake wilkeys "jaws" bug TT?

Run a flywheel mounted alternator and all electric accessories...

 

[CarterKraft]

It would. E85 is another option and it's usually only about a 35% increase in consumption

Probably disregard my ramblings from a week old post

I swear it said I was on the current page...

 

[mobil1syn]

The SCS wouldn't be needed. Overkill for 3-400hp

simple, quick change gearsets and all the ratios. it wasnt a hp decision

 

[SLOWPOKE693]

simple, quick change gearsets and all the ratios. it wasnt a hp decision

Forgot about the QC gears, but damn those things are big and heavy

 

[vetteboy79]

Go the other way from single seat, cram in a 3rd seat

Plan on 1st passenger getting out to assist with with first shit rock trail winchfest, abandon in desert. Drop second guy at next winch fest, abandon. End race single seat and save 10 minutes getting back in car and refitted

Wasn't there a 3 seater in one or a few of the early KOH's?

 

[AgitatedPancake]

The bus that ran this year had at least 4 seats

 

[YotaAtieToo]

I don't know of any trans issues with the Yammy. Several companies are offering different ratios for them.
It beats the heck out of belts.

I think they are good for what they're designed for, but haven't heard much good about crawling with them.

I feel like the belts have been plenty proven at this point.

 

[SLOWPOKE693]

I think they are good for what they're designed for, but haven't heard much good about crawling with them.

I feel like the belts have been plenty proven at this point.

The lack of low range in the YXZ makes it a shitty choice for a crawler.

 

[Provience]

Wasn't there a 3 seater in one or a few of the early KOH's?

666 used to race, easy 4 seats there

 

[JR4X]

I haven't heard of anybody blowing up a front or rear diff from anything other than a crash but I also don't know anyone running 300 plus hp through one either.

Diffs aren’t what I’d want out of it. We need a light powerful engine and transmission combo we can hook to a real transfer case and real diffs. Not having the belt is the plus. I’d want 600 reliable hp in my theoretical fantasy build.

 

[SLOWPOKE693]

Diffs aren’t what I’d want out of it. We need a light powerful engine and transmission combo we can hook to a real transfer case and real diffs. Not having the belt is the plus. I’d want 600 reliable hp in my theoretical fantasy build.

You are not getting 600hp out of any SxS engine that you want to last more than 5min

 

[JR4X]

You are not getting 600hp out of any SxS engine that you want to last more than 5min

Exactly

Except for maybe the new Pro R with a turbo on it. There’s a ton of YouTube dyno videos showing well over 600 whp. These guys at Larue turbo say 804 whp. Polaris so probably complicated and unreliable, like an LS

 

[bdkw1]

The easiest engine for us to use in our imaginary build would be a 1000+ cc motorcycle engine. Hayabusa turbo motors for example make stupid power, the transmission is already attached and figuring out reverse shouldn't be hard. Hell, put reverse in the transfer case like my Honda.

Busa trans wouldn't stand up to the abuse of a heavy car. It's also very close ratio. Hartley dose a Busa sans trans. BOLT 4 Specifications

 

[YotaAtieToo]

The lack of low range in the YXZ makes it a shitty choice for a crawler.

I know there are solutions. My old neighbor had a low gear set for the trans. Can't remember exactly how much it lowered each gear or whatever, but sounded like a compromise.

There was also a shift able box (2:1?) that went between the engine and trans, but that just doesn't seem like a great idea for U4 racing.

 

[mobil1syn]

I know there are solutions. My old neighbor had a low gear set for the trans. Can't remember exactly how much it lowered each gear or whatever, but sounded like a compromise.

There was also a shift able box (2:1?) that went between the engine and trans, but that just doesn't seem like a great idea for U4 racing.

tubeworks was making some gearsets for the trans for a while, not sure what happened with them.

 

[bdkw1]

tubeworks was making some gearsets for the trans for a while, not sure what happened with them.

They still make them.

 

[SLOWPOKE693]

Fortin also makes or made YXZ parts.

 

[YotaAtieToo]

A while back I was bs'ing with a guy at Fordyce. Can't remember where he said he worked, but he said they built a solid axle rear yxz that was a monster in the desert.

Not sure how that fits here, but

 

[YotaAtieToo]

PRIVATEER MOTORSPORTS/ASSAULT INDUSTRIES YXZ1000R TURBO RACE CAR
 - UTV Guide

With UTVs representing the fastest-growing segment of offroad racing, it’s quite common to come across spec-built race machines in the deserts of Southern California. What isn’t common, however, is to come across one that is seemingly a hybrid between a Yamaha YXZ1000R and a Baja-developed...

utvguide.net

Done a while back too

350hp out of the 1000cc engine.

Derp, guess this was that yxz

 

[vetteboy79]

666 used to race, easy 4 seats there

Nah...might be this one I'm thinkin of, Pistol Pete.

 

[Tech Tim]

Wasn't there a 3 seater in one or a few of the early KOH's?

Brandon Johnson?

You are not getting 600hp out of any SxS engine that you want to last more than 5min

Why are we even talking about UTV engines?

Are we talking a smaller 4400 car or a larger UTV?

 

[bdkw1]

Are we talking a smaller 4400 car or a larger UTV?

Yes.

 

[bdkw1]

Nah...might be this one I'm thinkin of, Pistol Pete.

Pete loved skiing jokes. I miss harrassing that guy.

 

[SLOWPOKE693]

Brandon Johnson?



Why are we even talking about UTV engines?

Are we talking a smaller 4400 car or a larger UTV?

Smaller lighter 4400 car. I have no use for a SxS engine outside of a SxS. There are far better choices for small, lightweight, powerful engines to use than those.

 

[triple_fcked]

So far we've got the tires settled on 37s.

Next up engine.... Which one?

Inline 4 to keep things small and tight or a V-6?

• Gotta hold up to 6 hours of hell.
• How much power?

Perhaps the VW 2.0TSI could have potential if someone figures out a transmission for it.

Makes excellent low end torque, 240whp@4500 and 273ft-lbs@1600 with a 6500 redline a stock in a GTI, and people are claiming a “reliable” 400+hp on street driven no prep cars. But it’s the internet so who knows, but it seems that the hard part is keeping the transmissions alive at that point.

Seems like direct injection motors have the best potential to make the most out of a small package engine.

But I’m a VW fan boy, German engineering all day

 

[Tech Tim]

the turbo's 3rz that ran in EMC and cleaned up for a while was reliable enough

3RZs are being built up over 900 HP for the drag strip and they are claiming a modded, but stock crank, so a realiable 350-400 is possible?

BUT... the 3RZ is an iron block with aluminum head and tip in just under 400 on the scale.

The newer 2TRs are also iron block/alum head. Maybe that's part of the reliability, but maybe we could shave close to 100lbs with an aluminum block?

The Ecotecs are all aluminum and have been built to over 1,000 hp and weigh around 330. BUT, they are an older engine, so missing some of the things that could make more efficient power.

The Caddie CT4 2.7 4cyl is all aluminum: 325 hp @5500 and 380ftlbs @2000-4000 rpm. The best weight I could find was "80 lbs lighter than 4.3".... so maybe around 300lbs?

Dry sump it and pick up an extra 25 hp?

The CT4 also has a 10 spd auto trans.

 

[ridered3]

Rumor has it Justin Hall is planning on or building an Ifs car. He has more real world racing and competitive crawling experience then 95%+ of the field but is on a working mans budget. It will be interesting to see whay he comes up with.

That’s a cool rumor.

I knew he was having a Shock Jesus 4800 built with plans to strip the current Sami 4500 at some point this year and finish out the 4800. Hadn’t heard about a possible IFS.

 

[Weasel]

There was v4 in spidertrax buggy sometime ago

Which they yanked out for an LS

Yeah Scat engine. It ran okay for comp crawling. It was yanked for the moon buggy that was built. I don't think it would be ideal.

Heck of a pass and example of gotta do what ya gotta do.

Schererer-er complimented him in an interview of that pass. Saying he would have never even thought to try that line.

Yelling at the TV for awhile about that line, cool to see Gomez spot and run it.

So all this talk about weight and size, let's get down to the biz of making things smaller and lighter.

Your biggest weight and size adders are the 40"+ tires, the engine/trans/t-case and the axles.

So the first step would be to drop tire size, that effects everything else.

Leading us to the question: Can 37" tires be competitive in the 4400 class at KOH?



Yeah, yeah, a golf cart crossed the line first on 37s blah, blah, blah.....

Yeah I think 37/38 would be a good size.

I like the idea of a 8-10 speed trans and still in the atlas camp.

Engine should be 300-400 hp with a good amount of torque. Desert guys like the BB cause of the torque curve at the lower revs. I don't have a wide range of engine but I like the 3800 Charged power output, in that power range with power right off the line. Bummer is it's pretty old and it's still in the 400# range. But the lower power side also means less cooling right? Always thought an air cooled engine would be cool but packaging and power probably kills that. A turbo or super I4 in the 2.0 range maybe be the ticket but it just sucks having all the extra plumbing.

What about running seats in tandem, like a Chenoweth? I don't agree with not running with a co driver.

Portals maybe, is alot of axle weight. Trusses and housing can be trimmed down more I think. HT trusses and housings.

And why is no one doing HT driveshafts? Seems like that would be a no brainer.

Oh and Hershal has alot of stuff he's always trying. Doesn't work often but he's certainly giving it a good go every time.