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Read the WELCOME ALL BMWFANATICS post.
E46 M3 Race Car build
- Thread starter P Smit
- Start date
P Smit
New member
I am posting some pics of the roll cage, manufactured from seemless Superform tubing, to FIA spec. Chromoly was a vey expensive option, almost double in cost, which I would have chosen if a sponsor paid for the build.
Note the two diagonal tubes that come from the B-pillar joint, down to the floor panel just in front of tha boot floor panel. Those two are also interconnected with similar tubing, just before the vertical ends penetrate trough the floor. The diff assembly is fastened to this subframe to prevent tearing of the boot floor due to high stress loads caused by hard acceleration and cornering.
Total cost of the complete cage, which also include a new subframe behind the fire wall, a subframe that holds the steering column and subframe extending through the firewall to the front quarter sections.
It is basically a touring car cage but with a little less tubing strengthening the front section of the engine bay.
Welding joints are of high quality. You will notice that the roof panel had to be removed to enable a proper installation of the cage. Nogal indrukwekkend nê!!
Enjoy!!
Note the two diagonal tubes that come from the B-pillar joint, down to the floor panel just in front of tha boot floor panel. Those two are also interconnected with similar tubing, just before the vertical ends penetrate trough the floor. The diff assembly is fastened to this subframe to prevent tearing of the boot floor due to high stress loads caused by hard acceleration and cornering.
Total cost of the complete cage, which also include a new subframe behind the fire wall, a subframe that holds the steering column and subframe extending through the firewall to the front quarter sections.
It is basically a touring car cage but with a little less tubing strengthening the front section of the engine bay.
Welding joints are of high quality. You will notice that the roof panel had to be removed to enable a proper installation of the cage. Nogal indrukwekkend nê!!
Enjoy!!
there has been a move to softer steels than Chromoly because it takes multiple impact better and is more cost effective i would not loose any sleep over the steel choice :rollsmile:
you might still get subframe problems at a later stage because the rear mount points are not tied into the cage
then again if you have solid mounts on the subframe the load should be directed onto the front points because there is no deflection in the bushes so maybe overkill to tie in the rear points
over all a very good cage
do you have pics of how they penetrated the firewall in the front?
you might still get subframe problems at a later stage because the rear mount points are not tied into the cage
then again if you have solid mounts on the subframe the load should be directed onto the front points because there is no deflection in the bushes so maybe overkill to tie in the rear points
over all a very good cage
do you have pics of how they penetrated the firewall in the front?
Carbon
///Member
EDIT: I just noticed something, I think the pipe used is not seamless but rather ERW and not FIA compliant. (I hope I am wrong though)
In the above picture you can clearly see a blue-ish line along the length of the pipe, this is the heat affected zone of the seam weld by Electric Resistance Welding (ERW)
FIA Article 253, see section 8.3.3
Not really accurate. There are hundreds of steels viable for roll cage construction as long as the cage is designed for it. Cr steels are very nice to use because of the big difference between its yield and ultimate tensile strengths.
Cr steels are avoided because of the welding difficulties. Same reason why Ti is almost never used.
T45 is a common replacement for Cr steel using the MIG process.
Reynolds 531 if you can find it.
My point is, cost is the biggest factor, and a cheaper material does not mean a unsafe cage, it is just heavier.
In the above picture you can clearly see a blue-ish line along the length of the pipe, this is the heat affected zone of the seam weld by Electric Resistance Welding (ERW)
FIA Article 253, see section 8.3.3
moranor@axis said:
Not really accurate. There are hundreds of steels viable for roll cage construction as long as the cage is designed for it. Cr steels are very nice to use because of the big difference between its yield and ultimate tensile strengths.
Cr steels are avoided because of the welding difficulties. Same reason why Ti is almost never used.
T45 is a common replacement for Cr steel using the MIG process.
Reynolds 531 if you can find it.
My point is, cost is the biggest factor, and a cheaper material does not mean a unsafe cage, it is just heavier.
Carbon@TheFanatics said:
dont disagree on cost, weight and welding but a slightly more malleable thicker wall steel does seem to perform better with multiple impacts... theory as i see is the thicker wall thickness makes for a stronger structure once some walls of the tubes are dented from the 1st impact
this is still highly debatable as i have not seen any hard evidence presented but rather anecdotal observations by some rally teams
P Smit
New member
Fanatics, Friday was such an exciting day, when after a tough week in the high court in Pta, I was rewarded by seeing and collecting my car from Fast Development!!:rollsmile:
My oldest son hopped in behind the steering wheel and said: ek kry pa by oom Izak, ons trek hom sommer dáár op die trailer!
Ha ha!! He forgot thet he did not bring his spacer cussion, to help him sit closer to the padals, I felt so sorry for him but for myself.....I grinned and knew this first drive with the new clutch kit, front discs and shorter diff was meant for only myself!
Oh my goodness......the M3 pulled out at Zwartkops with a new, fresh, crisp and lively gallop in it's pace and acceleration!!
Yesterday I had more negative front camber dialed in at my favourite wheel alignment specialist and sponsor in Pietersburg, John T Wheel Alignment.
My signage sponsor also came to measure the car to prepare the stickers as well as a very special design pattern to be put on certain surfaces of the body, of which will be kept a secret until it's done....you have to wait for the pics after the signage is done.
Next weekend will be the car's first race weekend, the BMW Gauteng Car Club's Bridgestone Challenge, at the big Z!!
I cannot wait to be dropped onto the grid between the pigeons....
The race sponsor stickers were put onto the car yesterday, a few pics will follow.
Here is a short acceleration video clip
My oldest son hopped in behind the steering wheel and said: ek kry pa by oom Izak, ons trek hom sommer dáár op die trailer!
Ha ha!! He forgot thet he did not bring his spacer cussion, to help him sit closer to the padals, I felt so sorry for him but for myself.....I grinned and knew this first drive with the new clutch kit, front discs and shorter diff was meant for only myself!
Oh my goodness......the M3 pulled out at Zwartkops with a new, fresh, crisp and lively gallop in it's pace and acceleration!!
Yesterday I had more negative front camber dialed in at my favourite wheel alignment specialist and sponsor in Pietersburg, John T Wheel Alignment.
My signage sponsor also came to measure the car to prepare the stickers as well as a very special design pattern to be put on certain surfaces of the body, of which will be kept a secret until it's done....you have to wait for the pics after the signage is done.
Next weekend will be the car's first race weekend, the BMW Gauteng Car Club's Bridgestone Challenge, at the big Z!!
I cannot wait to be dropped onto the grid between the pigeons....
The race sponsor stickers were put onto the car yesterday, a few pics will follow.
Here is a short acceleration video clip
@P Smit....die hele blerrie kar is indrukwekkend !!! Very nice approach to this whole rejuvenation of not only a M car, but a superb race car.
@Carbon, your observation is 100% correct...it is indeed a seam welded tube. If I am not mistaken, Chromoly tubing is extruded as opposed to seam welded hence the cost.
@Moranor, I concur about the cage - besides the weight savings that Chromoly tubing offers, there are no other real benefits. The material plays a factor in structural integrity - however, the structural construction is where the true strength comes from. As long as the tubes don't come loose under impact and impale you...a cage is a cage.
I would also raise the point, that I would never want to test a cage, but rather just make sure I have one, incase I need it.
Keep us updated....And I must say, the choice of interior colour...well....its just perfect.
@Carbon, your observation is 100% correct...it is indeed a seam welded tube. If I am not mistaken, Chromoly tubing is extruded as opposed to seam welded hence the cost.
@Moranor, I concur about the cage - besides the weight savings that Chromoly tubing offers, there are no other real benefits. The material plays a factor in structural integrity - however, the structural construction is where the true strength comes from. As long as the tubes don't come loose under impact and impale you...a cage is a cage.
I would also raise the point, that I would never want to test a cage, but rather just make sure I have one, incase I need it.
Keep us updated....And I must say, the choice of interior colour...well....its just perfect.
Dewald Basson
///Member
Check what featured on my Facebook :clapper:
Donovan2412
///Member
So clean :clapper:raise:
Awesome car!
raise:Awesome car!
Bernard///M3
BMW Car Club Member
Saw this car yesterday in person at Zwartkopz, man it looks great!! Really awesome looking car, pity it had a few teething issues!!
P Smit
New member
Hi fanatics!
Race day was a bit hectic, in qualifying session, an engine of another car had a serious electrical problem when a conrod smacked the starter and deposited a huge amount of oil on the racing line into turn 4!! Rally experience saved my day as I was able to yaw skid through this fast section and ended up exiting the curve on the edge of the pavement extension. Other cars skidded straight on into the gravel trap. Red flag came out and we pitted.
I had adjustments made to rear shock rebound settings going a 1/4 softer, and also dialed back on neg camber, as the car suffered slight understeer in turns 2 and six. Tyre wear on the fronts showed that the front susp had too much camber.
I qualified 2nd in class C and 7th overall for the first race with a respectable first attempt 1:12,1 . In the first race, the car still had understeer but much less than during qualiyfing. It took me some time to figure out which gear to select, 2nd or 3rd, for the tight corners. Reason for this is that the shorter diff ratio now renders shorter gears by implication
In lap 7, the alternator power wire touched the one oil cooler pipe, which melted the isolation and it caused a dead short, it was all silent very suddenly. I free-wheeled into the pit entrance and was towed to Freddie's shop. A few extra wires were charcoal and the fuel pump and and battery were cooked as well.
We fixed and replaced all the obvious damaged parts. Bit the car went into limp mode when started and driven. Freddie could only rectify a throttle sensor error when the guys with a DIS analiser pitched up on Tuesday. In the meantime I purchased a good used engine wiring loom from my good Friend Walt for a give-away price, just to make sure that we eliminate any future wiring problems.
Freddie and I decided to fit stiffer springs all round, as discussed earlier during the building process, to curb body roll, also decrease front rebound as well.
Lee will hopefully be able to test drive the M3 on or before coming Wednesday, to assist with final setup.
If rain does not prevent a Wednesday open practice session, I the car should be setup and prepared for the next event, which will be on the 21st, namely the ARRO sprint rally at Boekenhoudskloof Traffic College, in Pretoria West.
The shorter diff ratio works very well, adding to the torque rendering a very healthy figure of 375 Nm @5300 rpm increasing to 420Nm @ 7300 on the wheels, on F2 Vehicle Technology in Pietersbug's Dastek dyno. KW came to 195wkW @ 8000rpm.
I must say, the fine tuning of the suspension to the perfect settings, is só important for fast lap times. This car has a 1:08-1:09 potential at Zwartkops. I am considering a larger oil cooler as well, water temp stays at 90 degrees C, but the oil is getting very hot on a hot track day as it was on Saturday.
So, there you have the race teport after the first outing.
My great boet and friend Riaan Woest and me.
Uncle "Pete the Greek Vanos Expert" and yours truly.
My great dad and I. He is the proud owner of a 2011 BMW Z4 35iS, going full-out in his supprt for my racing.
Race day was a bit hectic, in qualifying session, an engine of another car had a serious electrical problem when a conrod smacked the starter and deposited a huge amount of oil on the racing line into turn 4!! Rally experience saved my day as I was able to yaw skid through this fast section and ended up exiting the curve on the edge of the pavement extension. Other cars skidded straight on into the gravel trap. Red flag came out and we pitted.
I had adjustments made to rear shock rebound settings going a 1/4 softer, and also dialed back on neg camber, as the car suffered slight understeer in turns 2 and six. Tyre wear on the fronts showed that the front susp had too much camber.
I qualified 2nd in class C and 7th overall for the first race with a respectable first attempt 1:12,1 . In the first race, the car still had understeer but much less than during qualiyfing. It took me some time to figure out which gear to select, 2nd or 3rd, for the tight corners. Reason for this is that the shorter diff ratio now renders shorter gears by implication
In lap 7, the alternator power wire touched the one oil cooler pipe, which melted the isolation and it caused a dead short, it was all silent very suddenly. I free-wheeled into the pit entrance and was towed to Freddie's shop. A few extra wires were charcoal and the fuel pump and and battery were cooked as well.
We fixed and replaced all the obvious damaged parts. Bit the car went into limp mode when started and driven. Freddie could only rectify a throttle sensor error when the guys with a DIS analiser pitched up on Tuesday. In the meantime I purchased a good used engine wiring loom from my good Friend Walt for a give-away price, just to make sure that we eliminate any future wiring problems.
Freddie and I decided to fit stiffer springs all round, as discussed earlier during the building process, to curb body roll, also decrease front rebound as well.
Lee will hopefully be able to test drive the M3 on or before coming Wednesday, to assist with final setup.
If rain does not prevent a Wednesday open practice session, I the car should be setup and prepared for the next event, which will be on the 21st, namely the ARRO sprint rally at Boekenhoudskloof Traffic College, in Pretoria West.
The shorter diff ratio works very well, adding to the torque rendering a very healthy figure of 375 Nm @5300 rpm increasing to 420Nm @ 7300 on the wheels, on F2 Vehicle Technology in Pietersbug's Dastek dyno. KW came to 195wkW @ 8000rpm.
I must say, the fine tuning of the suspension to the perfect settings, is só important for fast lap times. This car has a 1:08-1:09 potential at Zwartkops. I am considering a larger oil cooler as well, water temp stays at 90 degrees C, but the oil is getting very hot on a hot track day as it was on Saturday.
So, there you have the race teport after the first outing.
My great boet and friend Riaan Woest and me.
Uncle "Pete the Greek Vanos Expert" and yours truly.
My great dad and I. He is the proud owner of a 2011 BMW Z4 35iS, going full-out in his supprt for my racing.
born2boost
Member
Great achievement for the first time out...I did notice you stopping in the pit entry lane rushing to get the fire extinguisher...I had a very similar event with my car last year!! Luckily a fire striker close by killed the flames for me...
By going to stiffer springs you would get rid of some body roll but you will also induce even more understeer...
The car looks fantastic...well done!
By going to stiffer springs you would get rid of some body roll but you will also induce even more understeer...
The car looks fantastic...well done!
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