Once the trigger had been pulled in my mind to get this underway it was time to list all the things, visual or functional that I wanted the ute to have.
The ute of comparison for the build was a GM product out of the Australian division, General Motors Holden, the SS ute. It's dimensions are a bit bigger in width and length then the M5, but the M5's overhangs were shorter for better balance and handling.
In the initial discussions with Shane at SRC, we wanted the ute to have
some styling changes that would stand it apart from any normal M5. I didn't
think that was going to be too much of a problem.
On the engine front the 4.9 (5 liter) V8 M5 engine makes about 400-420hp now (Powerchip ECU program) and with time permitting VF in the USA will have a supercharger kit out for the M5 by late 07. Their plans are for it to run low boost 6lb and get about 600hp from a stock engine with stock headers (a weak point on a stock M5 engine) and with a stock exhaust. I plan on getting some Super Sprint headers, but not yet decided on what aftermarket exhaust I'll end up running out back. With a good set of SuperSprint headers and some free flowing cats and exhaust 600hp+ will be an easy safe target.
On the wheel front we decided that a staggered look would be the best option visually. A 19'' front and a 20'' rear would give the effect I wanted. The M5 normally came stock with 18'' rims. We wanted to gain some track width in the rear and did so with ease, but it was going to be a bit tricky to go bigger then 305/25/20 in the rear. I wasn't comfortable that a 25 series tyre would have enough side wall flex to make the ride on our Australian roads that much fun. It was decided that my connections with Bridgestone would pull me back to a more sedate 275/30/20. I would gain some side wall flex with the 30 profile and increase the total height of the tyre/wheel by about 25mm (1") so filling the guards a bit more. Some research on the M5 forum found that I could run 265mm fronts V's the OEM 245mm. The M5 is a heavy car 1,800kg (4,000lb) so that extra 20mm up front would be handy for cornering and braking traction.
The ride height was indeed a big consideration with what wheel/tyres I would end up running. I wanted the ute to have a ride height to be at about 640mm-650mm (25.25'' - 25.60) That was the same height that my US M5 was running but with 19" on all corners. This number was measured from the top of each wheel arch down to the ground. But with the bigger total height of the 275/30/20, 650mm+ might be more on the cars then 640mm all round.
Some external tweaks we wanted was to delete the door strips all the way around the car. This would freshen up the newness of the styling and pull the car forward 5-10 years in it's looks. We wanted to delete the door handles as well, this "shaved" look would go well with the super smooth finish with the panels being finished in black PPG paint.
Just adding a ute look to the rear half of the M5 could have been done, but Shane felt that the chassis needed a bit more tub length for the correct look. The final amount that we agreed upon that looked best for the extension was 125mm (5'') This extension was to be just in front of what is would normally have been the front edge of the back seat. The extension would give the ute a lower stance visually, so a bonus. The sails that would be needed to tie the roof to the tub would flow better with this extra length. The tub section in this extended form would actually be more ute like in size now. Not sure on how the balance will be in the final fit, but the M5 in stock form has a perfect 50/50 weight distribution, fingers crossed that we can keep it close and maybe loose some total weight as well.
We decided that the rear panels and rear bumper off a 5 series touring wagon would be ideal for a transplant for the ute. The reason the wagon parts seemed to be the right direction to go was that we needed a rear gate to swing down like a traditional ute. The rear light assembly on a "touring" was perfect, it has vertical sides so a gate would swing down perfectly.
We wanted the look (when viewing into the tub) for it to have traditional
styling, but of a very high quality.
The floor needed to have the usual ribs running along it, but maybe with some stainless steel strips on top of each rib to protect the paint and add some finish to the inside of the tub, this isn't totally decided on how it will turn out yet.
A custom one off rear strut brace will be made out of alloy for the two towers in the tub. This would be a great functional feature as well as visual one.
The fuel filler was to be removed from it's usual outer panel location on the outside wall to a new location on the inside wall of the tub.
I felt that some carbon fibre treatments would be a good touch in the
right places as well. The rear cover for the tub would be great in carbon.
This is still a goal of mine, but finding and making one that functions
perfectly that isn't too costly is going to be tricky. A reduction in
weight with some carbon parts is a good idea, but how much could be saved
I don't know yet. An all carbon GTR hood from Vorsteiner was on the "to
Knowing that the rear of the car has had some serious surgery and that all of the wiring needed to be moved and tracked to new location had us needing a storage compartment in the tub of some kind. What seemed to be the best option was to make use of what would have been the rear seat in the M5 sedan as a compartment for service and access. The new floor height was up enough from the old back seat that a decent compartment could be made. This would be a great location the CD stacker/Nav unit, fuses and so on that used to be in the trunk. What was normally the section for the air compressor in the floor of the trunk + a can of the tyre goo, would make a general storage area to keep small things off the floor.
The interior will have some custom adjustments as well. Not 100% sure on what will be the final fit internally for the ute, but some custom seats are on the cards and maybe some treatments to trim. I need to see what fits the best before a decision is made on seats.
Some adjustments to the sounds system will be a go, but I'd rather spend a bit more time/money on making the ute's engine sound be what I listen to.
So there you have the crux of what ideas have been floating around for the builds direction. I'm sure other things will evolve in the final part of the ute's build, but there's enough work for the guys at SRC to have it done by the end of Sept 07.