Off road racing Diesel engine considerations

I’m building an off road vehicle to compete in a off road racing event that is both desert racing and rock crawling combined in to one event. It’s also a semi endurance event. I’ve this vehicle will have full independent suspension, mid/rear mounted engine and 4 wheel drive. Diesel engines are rarely used in this event, so I plan to not one change this, but want to be competitive. The Cummins 4BT engine would be the go to engine for this type of build, but it can’t reliably make the power needed to go 100 plus MPH in the desert sections, and have the throttle response to crawl through the rock sections with decent fuel economy. So, I have been looking in to the V10 TDI and the V12 TDI engines. But I need more specifications on these engines. What are the physical dimensions and weight of these engines? Also, what kind of power are these engines capable of with moderate upgrades; turbo upgrades, fuel upgrades, and ECU tuning? What would be considered safe RPM limits of these engines? Any information would be appreciated, I can’t find much info via google.

Are you building a KOH rig? Ultra4

KOH. Full tube chassis, full independent suspension, geared hubs, 2 speed T case, 6 speed trans, central tire inflation system, running on 40s. Hoping to get away with twin VNT turbos and diesel powered. If I could engineer a way to control dual VNT/VGT turbos in a compound set up, it would be a twin compound system. But i am concerned about negelecting the instant throttle response and power of a twin VGT/VNT system.

1.9ZOOK said:

Are you building a KOH rig? Ultra4

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What's your target power range?

The BHW has easy ecu tuning, sub 400 lbs i believe, cheap to obtain, with rods injectors and studs capable over 200hp. Much broader or "streetable" power band than a 4bt. The large tdi motors you're looking at are $$$$ even before the mods. Just a stage 2 BHW requiring no upgrades on stock engine is 170hp 300ftlbs approx output. As for 100 mph...that's all in gearing. Peak torque is between 1900 and 2400 rpms. Well above a 4bt comfortable stock cruising rpm.


Already guys running compounds on it so your not having to break new ground.

A 6L80E, compound turbo 4BT rig has ran the race. At 70PSI boost, 3K EGT sustained and 1mpg. That engine is/was capable of 400-500HP. We’re competing against 600-800 hp vehicles. 200hp, even 300hp is not going to get the job done turning 40inch tires. That 4BT running 40s WOT was only able to sustain 55-60mph in the desert with a 6 speed trans(dbl over drive) and 5.13:1 gears.

A v10 is surprisingly light weight
So if you can shoehorn it under the hood then it's awesome choice.
if I recall correctly, the double eagle did nearly 800 ft-lb on the dyno and 550-600 ish hp. So when mildly modified nothing can beat it in power to weight if that is a concern, because the engine itself weighs less than 600 lb with everything on it.
You won't need anything like 70 psi boost to get those numbers, either... that was 22 psi wastegate turbos. 1400F max EGT at those numbers and 237 mph over a 7 mile run at bonneville.

It’s a full tube, custom built chassis, and we’re planning on building the vehicle around the power train, so fitment is no so much of an issue. Think of it as a tube chassis 4 wheel drive, 4 wheel independent suspension buggy. We want to show those LSX cars/buggies that we can play in the big leagues as well. Plus make waves in the custom fab industry for the yong company (not mine, I’m just acting as a consulting, technical advise arm for them)

A good friend of mine races in the ultra 4 class (4400 group)and they are running
37's,so you might not need 40's.,it would save some weight and rolling mass.

We were figuring that the roll out of the tires would give us some MPH in the desert sections and that the size of the tire would allow for the larger rocks to be easier to climb with out having to beat the car up to much. But this is all theoretical. I do know 90% of the vehicles run in the 37-42 range tire size. We are definitely open to a lighter, smaller tire though given the unsprung weight and ease of track side tire changes should a tire have to be changed on the trail side.

Our strategy is that the geared hubs will cut the drive line stress in half while giving some gear reduction, the central tire inflation system will allow us to air up for the high speed stuff, and allow for airing down for maximum traction in the rocks, the over drive transmission will allow for higher MPH in the high speed sections, the independent suspension system will not beat up the driver and navigator while giving maximum ground contact and traction while giving ungodly amounts of articulation and maximum ground clearance and approach/departure angles, and the engine will give us all the torque and horsepower we could ever want while giving us the best fuel economy. If we can skip every other pit stop and keep moving, we don’t have to be the fastest out there. The weak link at that point is driver and navigator fatigue. which we hope the super expensive, high tech suspension/4 wheel drive system will mitigate the fatigue issue.

I really don't know anything about the V12 tdi, but it should have good internal balance. The V10 would be cool too, imo. Have you considered the BMW M57 or N57? They can probably muster 500+ hp and still give respectable fuel economy.

No I haven’t. I had an alh powered Jetta back in the day. I have no idea what kind of power it made. But for a diesel it would rev high, returned great fuel economy, and made a decent amount of power for the mods I made. After that car, I had an LBZ duramax that put down mid 700s hp down on the dump and again, for the power, returned great fuel economy. As a tech, I’ve worked on and modified 4BTs in s10 and Jeep swaps, 6BTs (12/24 valves), QSBs, QSMs, QSFs, and ISX engines, International VT444s, VT365s, VT275s (ford ranger swaps), DT466/540s, CAT C16/18 ACERT and non-ACERTs, Detroit 60s, 8V92s, 12V92s, and the DD series engines along with the IDI 6.2/6.5/6.5T engines, and the ford scorpion powerstroke engines. Everything for triple and double compounds, injection pumps, injectors, block up builds and everything in between, along with most drive train components. I know these engines are way to big and heavy for what where trying to do. I do know the V10 and V12 TDI engines are incredible engines, and they seem, from my limited knowledge on them, to be exactly what we need. BMW diesels were/are my third choice for a power plant. With Mercedes being right there with the V10/V12 TDI

V10 will get you to where you want to be, but the key to making it work is the tuning.

There are a lot of tricky things if you want to use non-standard turbos (wastegate for example) and divorce from the auto transmission, and other standalone features like the instruments. It is not a DIY project and you will need to rely on others expertise for this, and there may be some trial and error. This is not a turn-key project. Nor is it a project for a backyard mechanic with big dreams but small means, expecting vendors to engineer the project for him.

Flashes can be done over OBD with the V10. However, the V12 cannot be flashed over OBD which would make development far more cumbersome and time consuming, even though a stock v12 would pretty much already be good to go as stock trim in the power department. It's all the "standalone" type things that might complicate matters with the V12, which is also pretty much untested in a standalone application and the engine itself is massively expensive to procure, if you can find one. It is also not known whether the immobilizer could be disabled to even have it run. That leaves the V10 as a no-brainer in my book. Unless you have the budget to talk with bosch for some motorsports ecus specially made for this project, lets say 6 figures on up.

when it comes right down to it, the power to weight the v10 TDI can't be beat.

KERMA, thank you for that information. We also don’t want to stray away from an automatic transmission. Torque converter selection is critical though. The farthest we want to get in to the engine is to fire ring it and head gaskets obviously. If we can just upgrade injectors, injection pump, lift pump, intake and exhaust manifolds and Turbos (non-gated) that’s where we want to be. We have access to extrude honing, CAD computers, plasma tables, full machine shop. We’re not wanting or asking any vender to do it for us. When it comes to tuning, that’s not my wheel house, so I’m not going to even attempt it. A tuning vender will be selected after research and he/she will ether be flown out to the vehicle or the car will be shipped to them to get that wizardry all hammered out. But the decision hasn’t been put in stone yet for what engine and transmission is going to be used. We have the suspension, CVS, Hubs, and differentials assembled on their way from Australia.

Personally, I'd opt for the OM606 with a manual pump and 7mm or 7.5mm elements. They can produce ungodly amounts of torque and are bulletproof.

Just for putting numbers out, a 6.0 L V12 CR Tdi engine is available from Cascade German for $ 100,000. Since complete V10 are available for at most a quarter of this price unless having a CR 24 hrs of lemons derived engine is important to you the V10 is the way to go.
A couple of things to consider for endurance off road racing:
Dust intrusion into the drivers compartment can reduce visibility to the point where you can't see the instrument cluster.
Vibration isn't just hard on the drivers but electrical connectors and wiring harnesses as well. The problems caused by big shakes can be hard to diagnose due to the transitory nature. Upgrade the stock electrical connectors and test them on a shaker table if available.

3k EGT Sustained? Wow!

What are they using they using for manifolds and turbine housings since cast iron melts around 2.2k and stainless around 2.8k?

It is a complete custom built crate engine from industrial injection with compounds, assuming that it’s a divided manifold and twin scroll HX30 or 35 with a HX40 on top of it. P-pump with 13-14mm plungers, some large injectors, and no aftercooling with a 3-4” straight pipe exhaust system. GM 6L80E built by monster transmissions (garbage company with a track records of installing used parts and claiming them as new). And the TCM only going off of shaft speed sensors for shift points. And to lose of a converter. EGT Gauge showed 3K degrees for miles through the desert with top speed being about 55-60mph. Fried the trans and ran out of fuel.

The arclight Scout?

So those HX's have ceramic turbine wheels and housings or what?

Probably inconel turbine wheels. The metal in the turbo/manifold/head never gets to the same peak temps as the exhaust gasses. 3000°F does seem scary high though.

Yes, that scout. Cool arse truck, but definitely was not the proper choice of drivetrain given the event that was attempted. It was this build that gave the idea, “let’s See if we can be successful!!!” And now sparks are flying, cad drawings are being made, and things are getting tig welded. My self and a few others are looking high and low for a good V10 that’s going to make a home in this buggy

I have no idea in that particular build. I do know that the EGT gauge was pegged at 3K degrees. Now obviously the accuracy of the gauge, thermocouple, and location all play a role in giving accurate data.

Not knowing anything before this thread about the "Arclight scout" i did some searching.I also looked up some info on the "double eagle" that I did know a little about.

KERMA said:

A v10 is surprisingly light weight
So if you can shoehorn it under the hood then it's awesome choice.
if I recall correctly, the double eagle did nearly 800 ft-lb on the dyno and 550-600 ish hp. So when mildly modified nothing can beat it in power to weight if that is a concern, because the engine itself weighs less than 600 lb with everything on it.
You won't need anything like 70 psi boost to get those numbers, either... that was 22 psi wastegate turbos. 1400F max EGT at those numbers and 237 mph over a 7 mile run at bonneville.

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https://www.drivingline.com/articles/the-237-mph-volkswagen/

Is the dyno run below the best one ?

https://www.facebook.com/agautowerks/photos/pcb.1153951108009274/1153945711343147/?type=3&theater

Was it using nitrous and/or water injection as a power adder? Not doubting that it made good power numbers but I find it hard to believe that it made 550-600 hp on diesel fuel only @ 22 psi boost with k16 turbo's while maintaining somewhat sustainable EGT's.

Hats off to you if that's the case.

DieselTechMike said:

It is a complete custom built crate engine from industrial injection with compounds, assuming that it’s a divided manifold and twin scroll HX30 or 35 with a HX40 on top of it. P-pump with 13-14mm plungers, some large injectors, and no aftercooling with a 3-4” straight pipe exhaust system. GM 6L80E built by monster transmissions (garbage company with a track records of installing used parts and claiming them as new). And the TCM only going off of shaft speed sensors for shift points. And to lose of a converter. EGT Gauge showed 3K degrees for miles through the desert with top speed being about 55-60mph. Fried the trans and ran out of fuel.

Click to expand...

https://www.drivingline.com/articles/an-improbable-scout/

Borg warner turbo's were used.I'd say that they were fairly large for a 4bt judging by the size of the secondary/high pressure turbo in the picture.

I'm currently rebuilding my rock race buggy with 40"tires,th350,d300,d60/14bolt (4.10 gears) and a 2.0L 300HP BHW TDI.Based on research and consultation I will need approx 39psi/2.7 bar boost to make 300hp.The nozzles I'm using are Firad +100% and I upgraded to a Darkside billet camshaft to help ensure that the engine makes a true 300 hp.I also upgraded the valve springs and added headstuds to hopefully keep things happy.My low pressure turbo is a "super hx30" with a 47mm compressor inducer.

I don't fully expect that this engine will be able to handle 100% power for a sustained period like KOH.I will only run full power for mabye 5-10 second bursts.I do compete mostly against lower to meduim powered v8 powered buggies in my class and did well last year with a 160hp TDI.I tied for 3rd in points in the TMR Customs race series last year.The series I compete in is nothing like KOH but its worth mentioning that I don't think that a 5.0L diesel will be competitive and/or finish KOH.

I'd have to attempt to stick with something like a 6.6L duramax with compounds and hope that it could sustain the beating while keeping cool at the 600+ hp needed to be competitive.Keeping a diesel alive is one challenge however building a trans and keeping it cool is a whole other challenge.

Just some food for thought

stock dynos for that v10 were 200-ish hp and ~400 ft-lb before mods After we got it out of limp mode. Factory EGR etc intact. So race ready was a sizeable percent gain from stock.

Beat my chest time, I was not the first to take a crack at it, one "big name" everyone knows here made all of 57 hp never got out of limp mode, and some famous guys from across the pond too. Never got out of limp mode, even with stock turbos and 100% stock engine. So first thing we did was work that bit out.

I'll have to go back over the timeline, but I think those dynos may actually have been stock turbos in 2016. Best in 2017 with wastegate was 750 ft-lb if memory serves. All motor. No power adders. (translate to 2liter 4cyl and it's 300 ft-lb, not so unreasonable if you think about it) There is a lot left to get.

More power will need more air. it will also need rethinking the turbos because power and torque actually went down as boost was added above that 21psi. It was hard to keep traction on the dyno at 21 psi.

The wastegate turbos for 2017 were something of a technical challenge for tuning, electric servo actuator delete and all that, but they sure seem to breathe better (a lot better) than the vnt. I'm actually trying to convince them to use a blower for next year. That would be the bees knees IMO.

I really like the idea of a blower for these race applications where no space or packaging constraints. And who gives a hang about emissions for this. The offroad.com samurai used a AWIC blower on an AHU and it was awesome. (I know... AHU? meh)

andy2 said:

Not knowing anything before this thread about the "Arclight scout" i did some searching.I also looked up some info on the "double eagle" that I did know a little about.



https://www.drivingline.com/articles/the-237-mph-volkswagen/

Is the dyno run below the best one ?

https://www.facebook.com/agautowerks/photos/pcb.1153951108009274/1153945711343147/?type=3&theater

Was it using nitrous and/or water injection as a power adder? Not doubting that it made good power numbers but I find it hard to believe that it made 550-600 hp on diesel fuel only @ 22 psi boost with k16 turbo's while maintaining somewhat sustainable EGT's.

Hats off to you if that's the case.



https://www.drivingline.com/articles/an-improbable-scout/

Borg warner turbo's were used.I'd say that they were fairly large for a 4bt judging by the size of the secondary/high pressure turbo in the picture.

I'm currently rebuilding my rock race buggy with 40"tires,th350,d300,d60/14bolt (4.10 gears) and a 2.0L 300HP BHW TDI.Based on research and consultation I will need approx 39psi/2.7 bar boost to make 300hp.The nozzles I'm using are Firad +100% and I upgraded to a Darkside billet camshaft to help ensure that the engine makes a true 300 hp.I also upgraded the valve springs and added headstuds to hopefully keep things happy.My low pressure turbo is a "super hx30" with a 47mm compressor inducer.

I don't fully expect that this engine will be able to handle 100% power for a sustained period like KOH.I will only run full power for mabye 5-10 second bursts.I do compete mostly against lower to meduim powered v8 powered buggies in my class and did well last year with a 160hp TDI.I tied for 3rd in points in the TMR Customs race series last year.The series I compete in is nothing like KOH but its worth mentioning that I don't think that a 5.0L diesel will be competitive and/or finish KOH.

I'd have to attempt to stick with something like a 6.6L duramax with compounds and hope that it could sustain the beating while keeping cool at the 600+ hp needed to be competitive.Keeping a diesel alive is one challenge however building a trans and keeping it cool is a whole other challenge.

Just some food for thought

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Most of I/I stuff is for the drag racer and tractor pulling crowd. Not knocking them. But it is what it is. With the duramax engine, the logical choice would be the LBZ. With just a reflash 550-600 hp is attainable. Factory VGT turbo with upgrades available and retain the VGT. It would need to be fire ringed heads and block, head studs, main studs, rod cap studs and H beam rods. The concern with this engine was weight when combined with an Allison 1000, and fuel consumption.

But you do have a point here with being able to sustain 100% load for long periods of time in the enviornment; keeping fluids cool becomes the priority.

turbobrick240 said:

Probably inconel turbine wheels. The metal in the turbo/manifold/head never gets to the same peak temps as the exhaust gasses. 3000°F does seem scary high though.

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Inco melts around 2700°F. It'd be slinging off globs of the wheel pretty quick.

I'm thinking there was an instrumentation issue.

Here's your donor:

https://www.copart.com/lotSearchResults/?free=true&query=touareg tdi

LBZ duramax and Allison 1000 combined weight dry: 1,165 LBS. the engine is approximately 865 lbs and the trans is 330 lbs dry. 06-07 model years maximum input torque rating is 650 lb-ft, and the 2011-2016 model years maximum input torque rating is 765 lb-ft. 660lb-ft for 08-2010 model years. 13 qts is the maximum fluid capacity in stock form. The gear ratios are;
3.094:1 first gear
1.809:1 second gear
1.406:1 third gear
1:1 fourth gear
.711:1 fifth gear
.614:1 sixth gear (only 2006 + model years had 6th gear)
4.48:1 reverse

ATS makes a deep trans pan for it that would increase the over all fluid capacity by 5 qts. And has cooling fins made in to the pan. RevMax fully built transmission capable of handling 1,500HP is available. To maintain fluid temperature, dual stand alone heat exchangers could be used. To protect fluid lines and ease routing of the fluid lines, we could use the tubes of the chassis as fluid lines. This could be done with trans fluid, engine coolant, engine oil, and power steering fluid. We plan on running a hydroboost brake booster. Evans waterless engine coolant is also what we plan on using. We also are planning on using the largest capacity fluid coolers we can find, each with their own electric fans.

As for the engine, because we don’t have to work with in the confines of an engine compartment, we could remove the valley mounted single turbo, and build a twin turbo system like a conventional V type engine. I think it’s paramount to keep the functionality of the VGT systems for quick spool up and throttle response. Also using ceramic coating and/or heat wrap/headset wrapping and turbo blankets to increase the responsiveness of the turbos is a must. Extrude honing the heads, ceramic coating the piston tops and exhaust runners, interior and exterior of the exhaust manifolds, and exterior of the intake manifold should also help increase thermal efficient. It is possible to run dual CP3s, and those CP3s can also be modified for tremendous fuel flow; Industrial Injection dialing dragons flow enough fuel to support 2K HP. Though those kinds of power numbers are not what we want. If we use a Duramax, 700-800HP would be more than enough. The rest of the drive line, to include the geared hubs and CV axles have been proven to take extreme abuse at those power levels and survive.