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-   -   Steel City Racing: King of the Hammers 2019 Toyota 4Runner IFS 4600 Build Thread (https://www.pirate4x4.com/forum/toyota-truck-4runner/2660392-steel-city-racing-king-hammers-2019-toyota-4runner-ifs-4600-build-thread.html)

Black Sheep 06-28-2018 09:11 PM

Quote:

Originally Posted by yotota (Post 43944704)
The debate you hear about 5.29s being weak applies to cheap gears. You're planning to actually race... So don't get cheap gears. Problem solved. Get the best damn 5.29s you can find, spool the rear end, and ARB the front. ATRAC will be worthless if you're actually hammering through something (I have ATRAC on my daily driver/snow/hiking truck, it works for very mellow stuff but it's obtrusive as hell). ABS will also be worthless, bordering on dangerous at desert speeds. Gut all that crap and run new lines straight to the calipers.

You really should gut anything and everything that won't make the rig faster at KOH, or anything that will be less than 100% reliable so you can actually finish KOH. ATRAC and ABS should go first thing.

Good advice.

Wilson 06-28-2018 09:19 PM

Quote:

Originally Posted by yotota (Post 43944704)
The debate you hear about 5.29s being weak applies to cheap gears. You're planning to actually race... So don't get cheap gears. Problem solved. Get the best damn 5.29s you can find, spool the rear end, and ARB the front. ATRAC will be worthless if you're actually hammering through something (I have ATRAC on my daily driver/snow/hiking truck, it works for very mellow stuff but it's obtrusive as hell). ABS will also be worthless, bordering on dangerous at desert speeds. Gut all that crap and run new lines straight to the calipers.

You really should gut anything and everything that won't make the rig faster at KOH, or anything that will be less than 100% reliable so you can actually finish KOH. ATRAC and ABS should go first thing.

I also agree. I believe in the platform, but step one (for me) would be to remove everything below the frame rails and inside of the cabin.

Atrac works well enough in my 100 series cruiser to get to some good camp sites. I would never run it in a race car.

arickvan 06-29-2018 09:10 AM

okay i ran the numbers!!! from what i can find you have a A750E 5 speed auto correct?

if so then it will be 4.56 diff with 4.3 case vs 5.29 diff with 3.8 case (assuming we want a fairly low 1st gear)

both have very similar crawl ratios ~70-1 1st gear ~43-1 2nd gear and ~28-1 3rd gear

the difference between them is in high range the 4.56 will be higher (16-1 1st gear 10-1 2nd gear and 6.5-1 3rd gear)

5.29's will be (18.5-1 11.5-1 and 7.5-1)

from this i looked at tcase in high what rpm and mph you come out with and we see 3rd gear being probly being the highest gear your going to use (assuming 50-70mph will be your max open desert speed)

okay finally the mph range for 3rd gear from 3000 rpm to 6000 rpm
5.29 diff with 3.8 case = 39-79mph
4.56 diff with 4.3 case = 46-91mph

so now the question is where are your shift points and where is your power and how can you keep the transmission and everyone on pirate happy all at once

(side note this is all a waste if you guys tell me 70-1 1st gear is too slow :homer: )

eat.sleep.wheel 06-29-2018 12:03 PM

70:1 1st gear is too low and completely unnecessary for what this rig will do.

50:1 would be plenty low

Charles4x4 06-29-2018 12:18 PM

Quote:

Originally Posted by yotota (Post 43944704)
The debate you hear about 5.29s being weak applies to cheap gears. You're planning to actually race... So don't get cheap gears. Problem solved. Get the best damn 5.29s you can find, spool the rear end, and ARB the front. ATRAC will be worthless if you're actually hammering through something (I have ATRAC on my daily driver/snow/hiking truck, it works for very mellow stuff but it's obtrusive as hell). ABS will also be worthless, bordering on dangerous at desert speeds. Gut all that crap and run new lines straight to the calipers.

You really should gut anything and everything that won't make the rig faster at KOH, or anything that will be less than 100% reliable so you can actually finish KOH. ATRAC and ABS should go first thing.

Agreed on the gears. Note we won't be engaging the ARB at any moderate or high speeds of course. If ATRAC is a hindrance (I've heard both sides of the debate), we'll pull it off ASAP in testing in Dec.

A few experts (literally fab shop owners with a ton of KOH experience) think it could really help. Others think not. We're going to leave ATRAC on for now and will pull it during testing if it's a hindrance.

ARBs Front and Rear are locked in.

Wilson 06-29-2018 12:36 PM

My experience with Atrac on my 100 series and it's variant in my tundra is that it works surprisingly well on mild trails and loose conditions. At speed, it dumbs down the power; favoring safety over speed (forget sliding a turn).

Charles4x4 06-29-2018 01:13 PM

Quote:

Originally Posted by arickvan (Post 43945354)
okay i ran the numbers!!! from what i can find you have a A750E 5 speed auto correct?

if so then it will be 4.56 diff with 4.3 case vs 5.29 diff with 3.8 case (assuming we want a fairly low 1st gear)

both have very similar crawl ratios ~70-1 1st gear ~43-1 2nd gear and ~28-1 3rd gear

the difference between them is in high range the 4.56 will be higher (16-1 1st gear 10-1 2nd gear and 6.5-1 3rd gear)

5.29's will be (18.5-1 11.5-1 and 7.5-1)

from this i looked at tcase in high what rpm and mph you come out with and we see 3rd gear being probly being the highest gear your going to use (assuming 50-70mph will be your max open desert speed)

okay finally the mph range for 3rd gear from 3000 rpm to 6000 rpm
5.29 diff with 3.8 case = 39-79mph
4.56 diff with 4.3 case = 46-91mph

so now the question is where are your shift points and where is your power and how can you keep the transmission and everyone on pirate happy all at once

(side note this is all a waste if you guys tell me 70-1 1st gear is too slow :homer: )

It's the A750F (not sure if there is a difference vs A750E).

Crawl Ratio / 3rd Gear 2500 to 5000 RPM / RPMs at 70 MPH in 3rd
4.56 with 3.0 = 48:1 / 40-82 MPH / 4,300 RPM
4.56 with 3.8 = 61:1 / 40-82 MPH / 4,300 RPM
4.56 with 4.3 = 69:1 / 40-82 MPH / 4,300 RPM

5.29 with 3.0 = 56:1 / 35-70 MPH / 5,000 RPM
5.29 with 3.8 = 71:1 / 35-70 MPH / 5,000 RPM
5.29 with 4.3 = 80:1 / 35-70 MPH / 5,000 RPM

I think we can hit 80 in the flats max. If we are targeting a 50:1 or 60:1 crawl Ratio in Low 1st, and if 4.56 is any stronger than 5.29, then 4.56 with a 3.8 case feels about right to me.

Nitro, Yukon, Other gears - what does everyone suggest? I'm ping them about potential sponsorship for the front diff.

Charles4x4 06-29-2018 01:14 PM

Quote:

Originally Posted by Wilson (Post 43945858)
My experience with Atrac on my 100 series and it's variant in my tundra is that it works surprisingly well on mild trails and loose conditions. At speed, it dumbs down the power; favoring safety over speed (forget sliding a turn).

Thanks. Doesn't it turn off automatically at a certain speed? I heard it cuts off.

Note we'll definitely be disabling VSC - there is a switch mod or something we'll install.

Charles4x4 06-29-2018 01:22 PM

Suggestions needed: What fuel cell should we be looking at? Recall it'll be mounted in the cargo area just behind where the rear seat is today.

After 5-mins of Google Searching, I found:
JAZ Pro Sport II 22 Gal Fuel Cell (JAZ28012206)

https://www.kartek.com/parts/jaz-pro...4w-10-12h.html

Is 22 Gal about right? I assume I'll be getting 8-12 MPG in race conditions? Should I go larger?

What about internal baffles? I've heard nightmares of foam disintegrating and being sucked through the filters, pumps, and lines. Is there an alternative to foam?

KOH Rules state:
d) Safety fuel cells shall consist of a bladder enclosed in a smooth-skinned container. The container shall be constructed of 20 gauge steel, 0.060 aluminum. Magnesium is strictly prohibited. Container must be securely attached to vehicle with bolts or steel straps. All fittings must be built into the container skin and bonded to the container skin as an integral part of the tank or mechanically sealed by a ring and counter-ring system by either flat joint or an O-ring. Internal baffling is mandatory in all fuel cells. Foam is an acceptable form of internal baffling.
Bladder construction shall be of nylon or Dacron woven fabric impregnated and coated with a fuel resistant elastomer. Rotary molded polymer cells are acceptable when encapsulated in a container constructed of 20 ga. Steel or 0.060 aluminum.

Bones 06-29-2018 01:45 PM

Dear god someone move this to the newb section. This is getting utterly ridiculous

Wilson 06-29-2018 01:45 PM

Quote:

Originally Posted by Charles4x4 (Post 43945952)
Thanks. Doesn't it turn off automatically at a certain speed? I heard it cuts off.

Note we'll definitely be disabling VSC - there is a switch mod or something we'll install.

The 100 series needs to be in low range, the tundra does have a disabling switch. Does your runner have a center diff in the tcase? I believe true awd could be advantageous

Wilson 07-01-2018 12:22 PM

Did your team consider the gm 9.25 for the front?

Charles4x4 07-03-2018 08:33 PM

Quote:

Originally Posted by Wilson (Post 43946006)
The 100 series needs to be in low range, the tundra does have a disabling switch. Does your runner have a center diff in the tcase? I believe true awd could be advantageous

Yes, it has a CDL, but will be pulled when the Atlas II goes in.

Charles4x4 07-03-2018 08:35 PM

Quote:

Originally Posted by Wilson (Post 43948334)
Did your team consider the gm 9.25 for the front?

Yes, but if the F9 won't fit, I doubt the GM 9.25 would fit? As mentioned above, most running 40s on Toyota 8" aren't breaking the gears, they're breaking the CVs. And we'll be running new prototype RCVs, so we should be covered there.

If we break the 8" in testing, we'll turn to alternatives.

Wilson 07-03-2018 09:06 PM

Quote:

Originally Posted by Charles4x4 (Post 43952772)
Yes, but if the F9 won't fit, I doubt the GM 9.25 would fit? As mentioned above, most running 40s on Toyota 8" aren't breaking the gears, they're breaking the CVs. And we'll be running new prototype RCVs, so we should be covered there.

If we break the 8" in testing, we'll turn to alternatives.

Depends.... the f9 is designed to be centered and is not contoured to fit around other components, as your 8" and the 9.25 are. Don't get me wrong, if this were my build step one would be to cut off everything below the frame rails and build from scratch.

Charles4x4 07-05-2018 02:37 PM

Quote:

Originally Posted by Wilson (Post 43952846)
Depends.... the f9 is designed to be centered and is not contoured to fit around other components, as your 8" and the 9.25 are. Don't get me wrong, if this were my build step one would be to cut off everything below the frame rails and build from scratch.

Good point. I'll look into the GM 9.25 and a Tundra 9" Clamshell.

Charles4x4 07-06-2018 07:23 AM

Quote:

Originally Posted by Wilson (Post 43952846)
Depends.... the f9 is designed to be centered and is not contoured to fit around other components, as your 8" and the 9.25 are. Don't get me wrong, if this were my build step one would be to cut off everything below the frame rails and build from scratch.

We measured again yesterday and nothing above the Toyota 8" will fit.

The only way to get a different front diff in there is to do what you said above - cut the factory cross members, which isn't allowed in the 4600 rules:

"Stock frame (frame is considered to be the primary frame rails and all permanently factory cross members) must be retained, and must be complete and unmodified. No material may be removed for any reason and no section of the frame may be 'massaged' or re-shaped with the following limitations and exceptions: The rear portion of the frame and rear cross member may be removed or trimmed for the sole purpose installing an aftermarket rear bumper. Frames may be reinforced by adding material."

So, the current plan remains.

Wilson 07-06-2018 08:50 AM

You see "crossmembers," I see "suspension mounting points."

Charles4x4 07-06-2018 09:00 AM

Quote:

Originally Posted by Wilson (Post 43956100)
You see "crossmembers," I see "suspension mounting points."

I've had countless racers tell me: "Don't overthink it - just follow the rules." I think that's advice I'm going to stick with.

And regardless - the purpose, and uniqueness of this build is that it is a true "Stock Class" build. Not a fully fabricated buggy that looks like a 4Runner. It'll be something that everyone who owns a IFS Daily Driver can relate to and aspire to. Will it win - I hope so! But first and foremost, it'll showcase what a well built Toyota can actually do at KOH, within the Stock Class 4600 rules.

As soon as I start "interpreting" the rules and cutting everything off, I've defeated my purpose and am no different than the 4500 and 4800 buggies.

My sponsors and I want to see how well an IFS based 4th Gen v8 4runner can actually do at KOH when armed with an amazing team, products, sponsors, and solid fabrication, where permitted and intended.

matzell 07-07-2018 06:55 AM

I will beat the "dead horse" again. You need acceleration! Lower gears will help with this. it seems you are looking at crawl ratio and 3rd gear. You need to accelerate in high range as well. You have a lot of sections that you will be in high range. In years past, 2016-2017 I ran the whole first lap in 4-hi. In low range use "Overdrive". No problem running 4th and 5th gears in the desert.

For reference, I have 5:38 axle gears, a 2:1 case and a 6 speed tranny. (37" tires) I have done 78 mph in 5th gear low range, across the lakebed and been below 6000 rpms and a gear to go. In 2017 I forgot to shift back to high after pit 2b and ran the rest of the race in 4 low. Had people behind me and did not want to stop to shift.

You have a 5 speed trans, use all the gears to your advantage and forget about this whole "3rd gear thing"!

I know you have a v-8 and it feels fast on the street. Take it out in the sand and see how it does in HIGH range and how much power if feels like it has. Last time I checked you will still be under 300 hp, which is not a lot in the "racing " world.

You ask for opinions on this site and others. Several racers with experience have responded and given you real world advise. Take the time to listen and learn from our experience. It is a race car. IF you want to still DD this then hit up Mall Crawler and see what he runs in his old 4500 car and ask him why he no longer races it.

montezuma 07-07-2018 01:54 PM

Have you ever been to the hammers, or been part of a desert race team?

pennsylvaniaboy 07-08-2018 12:24 PM

Quote:

Originally Posted by Charles4x4 (Post 43940712)
I actually had Brian at 4WU say the same. But with 4.56 gears and the big V8 swapping between Hi and Low, my team in CA thinks the 4.3 Atlas will work fine.

I'm no T-Case expert though, but I looked at the math using an online RPM to T-Case to Diff calculator and 2:1 didn't look like a good fit for both high-speed desert + rock crawling (or maybe rock bouncing is a better term). I can't remember the exact math though - maybe RPMs were too high in the desert and speed was too high in the rocks if I recall.

they make a 3.1?!

Charles4x4 07-09-2018 09:04 AM

Quote:

Originally Posted by matzell (Post 43957304)
I will beat the "dead horse" again. You need acceleration! Lower gears will help with this. it seems you are looking at crawl ratio and 3rd gear. You need to accelerate in high range as well. You have a lot of sections that you will be in high range. In years past, 2016-2017 I ran the whole first lap in 4-hi. In low range use "Overdrive". No problem running 4th and 5th gears in the desert.

For reference, I have 5:38 axle gears, a 2:1 case and a 6 speed tranny. (37" tires) I have done 78 mph in 5th gear low range, across the lakebed and been below 6000 rpms and a gear to go. In 2017 I forgot to shift back to high after pit 2b and ran the rest of the race in 4 low. Had people behind me and did not want to stop to shift.

You have a 5 speed trans, use all the gears to your advantage and forget about this whole "3rd gear thing"!

I know you have a v-8 and it feels fast on the street. Take it out in the sand and see how it does in HIGH range and how much power if feels like it has. Last time I checked you will still be under 300 hp, which is not a lot in the "racing " world.

You ask for opinions on this site and others. Several racers with experience have responded and given you real world advise. Take the time to listen and learn from our experience. It is a race car. IF you want to still DD this then hit up Mall Crawler and see what he runs in his old 4500 car and ask him why he no longer races it.

Thanks for all the great advice. I passed your suggestion along to the team. As long as we aren't locked into 4.56 in the RJ60, we still have time to make a change.

Thanks for bring it up again - your experience and advice are greatly appreciated!

Charles4x4 07-09-2018 09:18 AM

Update: I'm close to being finished with the DD - maybe 2-weeks left - then I can stop driving the 4th gen and the true tear-down begins. More updates below:

In Process:
- Front Suspension and Steering are being fabricated
- Front RCV Front Axle Shafts are being engineered
- Rear RockSolidToys 4-Link Suspension brackets are completed
- Rear Currie RJ60 is being made (not sure if they have done gearing or not yet)
- AEM Fuel System gauges (2) likely go in this week

Still working on:
- URD MAF Calibrator in the mail
- Fiberwerx Fenders in the mail
- PRP Seats being ordered
- Locking down sponsors for Armor and Tires
- Lock down fuel cell dimensions and dual-pump system

I'm also struggling to find reasonably priced 4th gen salvage doors shells (4) and lift gate to gut. If anyone knows of any in the Southeast, PM me!

the_white_shadow 07-09-2018 10:02 AM

Just gut the ones you have on the 4runner now. This a race car. No point in trying to keep it a daily driver. You have to pick one or the other.


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