CerberaV8Racings New Off-road Racer Project
Discussion
I don’t really share our stuff on here much as everything goes on our Facebook page. However the new project I have on the go may be interesting to some of you so I thought I would put it up here.
As most PH’ers know I race a Cerbera GT car and a very unique MK1 Escort Mexico. This new project thought is very different! (Post taken from our page)
At the end of last year I had an idea for an unusual and very exciting project..... unfortunately the Cerbera crash has meant slow progress. However now the Cerbera is nearly finished this new exciting project is fully under way.
Last year we dipped our toes into the off-road racing scene with our Bowler Tomcat. We had a lot of fun and the car was very competitive. However, I’m not a huge Rover V8 fan and kept thinking about more power. The easy option would have been to fit a 5.3 JE Rover lump...... but one of my spare 4.7 AJP V8 race engines kept looking at me from the engine bench, so a plan developed!
Off road racing is fun but my heart is on the race track. The project goal is as follows : Build the first ever AJP V8 Tomcat, making it competitive off road, stupidly fun on the road and able to do a sub 59 second lap of Brands Hatch!
The big first job was to work out how we would convert the AJP to 4X4 and what gearbox to utilise. Luckily we found a company called Rakeway engineering who specialise in custom CNC machining and engineering. So after lots of different ideas this is what we have ended up with.
The 4.7 AJP V8 connected to a standard Bell housing and race paddle clutch with lightweight flywheel. A custom bell housing adapter to fit a Tremec TKO600, this is then modified with a completely new cnc machined tail housing which allows a Land Rover LT230 transfer box to be fitted. This transfer box has then been modified so the gear ratios are right for the AJP. High and low gear options have been removed so it is just one direct ratio to make it all much stronger. Again the diff lock option has been removed and the box modified to be permanent 4 wheel drive.
The front prop shaft then runs to a centre bearing which has a clutch built in so the vehicle can be switched between rear wheel drive (track and road use) and 4 wheel drive for when off road. This also allows the prop shaft to “curve” around the AJP oil pump assembly. The positioning of the engine was very important, I wanted it as far back as possible and as low as it could go. Obviously the front axle travel was a concern so I had to avoid the front diff. Also the rear prop shaft length was a limiting factor. The engine sits in the engine bay at a slight angle to miss the nose of the diff and pretty much 8 inches off centre. The minimum rear prop length was 14” so that’s where the engine has been placed. The next job is having a set of manifolds made to fit and coming up with some air intake ideas...
The massive 12” travel suspension has been worked on by Fox Racing to make sure it will be quick on the tarmac whilst being acceptable in the off road races. The hydraulic Bump stops will help limit body roll when on the track. Quaife LSD’s are in the front and rear axles to make sure the power gets put down adequately. The strength of the axle internals is one area for concern at the moment.
The one thing you can’t compromise on is tyres, so two sets of wheels are going to be used. We have the 16” wheels with off road tyres for off road races and then spectacularly we have some 20x11” alloys with 335/35/20 R888 tyres for on the track! These will
Certainly look strange on this type of car but should really help with handling on track.
The brakes have been upgraded to Range Rover units but not the biggest versions as I need to be able to fit them inside the 16” wheels. With enough cooling I believe these should be adequate.
The aim is to have this finished over the next few months. Still lots of work to do, I need to make a fuel system up and create an electric power steering system to suit the Land Rover Steering box. All the electrics and plumbing need to be done also.
I can’t wait to take this on a race track!!!
Thanks Mike
(Edit to comply with posting rules)
As most PH’ers know I race a Cerbera GT car and a very unique MK1 Escort Mexico. This new project thought is very different! (Post taken from our page)
At the end of last year I had an idea for an unusual and very exciting project..... unfortunately the Cerbera crash has meant slow progress. However now the Cerbera is nearly finished this new exciting project is fully under way.
Last year we dipped our toes into the off-road racing scene with our Bowler Tomcat. We had a lot of fun and the car was very competitive. However, I’m not a huge Rover V8 fan and kept thinking about more power. The easy option would have been to fit a 5.3 JE Rover lump...... but one of my spare 4.7 AJP V8 race engines kept looking at me from the engine bench, so a plan developed!
Off road racing is fun but my heart is on the race track. The project goal is as follows : Build the first ever AJP V8 Tomcat, making it competitive off road, stupidly fun on the road and able to do a sub 59 second lap of Brands Hatch!
The big first job was to work out how we would convert the AJP to 4X4 and what gearbox to utilise. Luckily we found a company called Rakeway engineering who specialise in custom CNC machining and engineering. So after lots of different ideas this is what we have ended up with.
The 4.7 AJP V8 connected to a standard Bell housing and race paddle clutch with lightweight flywheel. A custom bell housing adapter to fit a Tremec TKO600, this is then modified with a completely new cnc machined tail housing which allows a Land Rover LT230 transfer box to be fitted. This transfer box has then been modified so the gear ratios are right for the AJP. High and low gear options have been removed so it is just one direct ratio to make it all much stronger. Again the diff lock option has been removed and the box modified to be permanent 4 wheel drive.
The front prop shaft then runs to a centre bearing which has a clutch built in so the vehicle can be switched between rear wheel drive (track and road use) and 4 wheel drive for when off road. This also allows the prop shaft to “curve” around the AJP oil pump assembly. The positioning of the engine was very important, I wanted it as far back as possible and as low as it could go. Obviously the front axle travel was a concern so I had to avoid the front diff. Also the rear prop shaft length was a limiting factor. The engine sits in the engine bay at a slight angle to miss the nose of the diff and pretty much 8 inches off centre. The minimum rear prop length was 14” so that’s where the engine has been placed. The next job is having a set of manifolds made to fit and coming up with some air intake ideas...
The massive 12” travel suspension has been worked on by Fox Racing to make sure it will be quick on the tarmac whilst being acceptable in the off road races. The hydraulic Bump stops will help limit body roll when on the track. Quaife LSD’s are in the front and rear axles to make sure the power gets put down adequately. The strength of the axle internals is one area for concern at the moment.
The one thing you can’t compromise on is tyres, so two sets of wheels are going to be used. We have the 16” wheels with off road tyres for off road races and then spectacularly we have some 20x11” alloys with 335/35/20 R888 tyres for on the track! These will
Certainly look strange on this type of car but should really help with handling on track.
The brakes have been upgraded to Range Rover units but not the biggest versions as I need to be able to fit them inside the 16” wheels. With enough cooling I believe these should be adequate.
The aim is to have this finished over the next few months. Still lots of work to do, I need to make a fuel system up and create an electric power steering system to suit the Land Rover Steering box. All the electrics and plumbing need to be done also.
I can’t wait to take this on a race track!!!
Thanks Mike
(Edit to comply with posting rules)
Edited by Scrump on Sunday 6th January 17:54
) - looking forward to learning more.
Sorry for the lack of updates!
She is now complete and we did our first track day last week.
She out performed all of my expectations! It was only really a shakedown so didn’t test the limits and never found the limit of grip so much more corner speed to come. Running the engine in meant we didn’t get over 3/4 throttle or 5750rpm but she still felt quick.
I was worried that it could be a real handful in the corners and unbalanced at speed but actually she felt planted and fast.
I didn’t push her too hard but started to push on a little bit in the afternoon which has shown some issues that I need to fix. The rear LSD couldn’t deal with the power/grip, once pushing on the inside rear would spin up. A new motorsport plate diff has been ordered to stop this. Also under heaven deceleration we had a horrible vibration, it turns out that the steering box is worn and was bouncing between left and right, this wasn’t noticeable with the narrow off road tyres and at lower off road race speed. An easy fix and a new steering box is already on. Unfortunately this limited our track time and meant I could only use half brake pressure.
The reworked Fox racing suspension worked really really well! In fact we generated so much grip that the inside front was lifting.... even with two live axles!
The original target was to be able to make this car fast on track, even with the above issues we have achieved this, it was quicker than the mx5’s and Clio’s through the corners and quicker than most things on the straights. Already with a lap time under a minute.
I can’t wait to get back out on track in her with these problems sorted and using the full power potential!
(Edit to comply with posting rules)
She is now complete and we did our first track day last week.
She out performed all of my expectations! It was only really a shakedown so didn’t test the limits and never found the limit of grip so much more corner speed to come. Running the engine in meant we didn’t get over 3/4 throttle or 5750rpm but she still felt quick.
I was worried that it could be a real handful in the corners and unbalanced at speed but actually she felt planted and fast.
I didn’t push her too hard but started to push on a little bit in the afternoon which has shown some issues that I need to fix. The rear LSD couldn’t deal with the power/grip, once pushing on the inside rear would spin up. A new motorsport plate diff has been ordered to stop this. Also under heaven deceleration we had a horrible vibration, it turns out that the steering box is worn and was bouncing between left and right, this wasn’t noticeable with the narrow off road tyres and at lower off road race speed. An easy fix and a new steering box is already on. Unfortunately this limited our track time and meant I could only use half brake pressure.
The reworked Fox racing suspension worked really really well! In fact we generated so much grip that the inside front was lifting.... even with two live axles!
The original target was to be able to make this car fast on track, even with the above issues we have achieved this, it was quicker than the mx5’s and Clio’s through the corners and quicker than most things on the straights. Already with a lap time under a minute.
I can’t wait to get back out on track in her with these problems sorted and using the full power potential!
(Edit to comply with posting rules)
Edited by Scrump on Sunday 6th January 17:57
So a good few years have passed now!
The truck has been reliable and has plenty of track time under its belt.
The rear ATB diff has been replaced with a full on track orientated Plate differential. We changed the air intake system which gained some extra power (but looks ugly) Better air intakes and brake cooling. We also fitted some lower springs with a much higher spring rate.
As the car has started to handle better we have come across a few issues. The first was spinning up the rear unweighted wheel, this was remedied by the diff change above. Next was the whole lifting a wheel issue. The truck has so much grip that it often lifts an inside front, this doesn't bother me and actually happens on the actual race cars sometimes.
The issue however comes with the inside rear lifting and causing loss of drive and transmission issues. Not to mention when the front and rear lift together! The only real way around this would probably spend a fortune on developing some proper anti roll bars and getting it even lower.
The one major stumbling block has been the off road racing. The gearing is just way to long. I have struggled to reach a good and easy compromise. One way is to have one rear diff ratio for track work and another for off-road. This is cheap but a couple of hour job each time to change.
The best way would be to have a specialist 2 speed transfer box made with custom ratios. This however would not be cheap!
I think overall the project has been a success, i just need to decide how much further i go with it. The whole idea was for it top be a compromise car that could do both track days and off road racing. This has been achieved but needs some money throwing at it to keep it competitive off road.
Here is a link to some in car footage from Brands, These was some passenger laps i did so not 100% on it but gives you the idea of the fun element!
Still getting it muddy as well!
The truck has been reliable and has plenty of track time under its belt.
The rear ATB diff has been replaced with a full on track orientated Plate differential. We changed the air intake system which gained some extra power (but looks ugly) Better air intakes and brake cooling. We also fitted some lower springs with a much higher spring rate.
As the car has started to handle better we have come across a few issues. The first was spinning up the rear unweighted wheel, this was remedied by the diff change above. Next was the whole lifting a wheel issue. The truck has so much grip that it often lifts an inside front, this doesn't bother me and actually happens on the actual race cars sometimes.
The issue however comes with the inside rear lifting and causing loss of drive and transmission issues. Not to mention when the front and rear lift together! The only real way around this would probably spend a fortune on developing some proper anti roll bars and getting it even lower.
The one major stumbling block has been the off road racing. The gearing is just way to long. I have struggled to reach a good and easy compromise. One way is to have one rear diff ratio for track work and another for off-road. This is cheap but a couple of hour job each time to change.
The best way would be to have a specialist 2 speed transfer box made with custom ratios. This however would not be cheap!
I think overall the project has been a success, i just need to decide how much further i go with it. The whole idea was for it top be a compromise car that could do both track days and off road racing. This has been achieved but needs some money throwing at it to keep it competitive off road.
Here is a link to some in car footage from Brands, These was some passenger laps i did so not 100% on it but gives you the idea of the fun element!
Still getting it muddy as well!
itsallyellow said:
Yes it certainly gets quite a bit of attention.
At the start of a track day people often come by and laugh and ask if were actually going to take it on track. Then towards the end of the day people still laugh but in a different more accepting way!
I love it... And applaud your endeavours to make it work in two very different (and not particularly mutually compatible) racing environments. At the start of a track day people often come by and laugh and ask if were actually going to take it on track. Then towards the end of the day people still laugh but in a different more accepting way!
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