Rear Diffuser on GTR
Discussion
In response to M3Desmos post about the whys and wherefores of a splitter on the GTR, I just thought I would throw this out there and see what people think/know? I will be having one fitted to the GTW but was wondering if any one actually has one on a car at the moment? Apart from the brass tacks of the modification, there are also the aesthetics to consider; I, like Desmo, think the splitter looks the tits and am sure the diffuser will complete the look.
www.grasser-rasing.com offers complete diffusers front, rear....specially designed for the GTR....
Could not agree with you more. I think a rear diffuser would definitely add to the aesthetic appeal of an Ultima. It also explains why I think that in standard form, black is the best colour - it carries the lines of the car so well.
Let's be honest here - not many of us who intend to use the car mainly for the road, really need to modify the performance hugely as we rarely (if ever) will explore the absolute limits of what this car is capable of. The aesthetics on the other hand are down to personal preference and there will always be differences in these preferences. The addition of a splitter and rear diffuser would in my humble opinion, improve the looks by making it look less kitcar-ish and more finished. The Ultima is one of the finest looking kits available and incredibly capable to boot and lends itself well to personalised modification - provided of course that the execution is as good as or better than the concept.
Let's be honest here - not many of us who intend to use the car mainly for the road, really need to modify the performance hugely as we rarely (if ever) will explore the absolute limits of what this car is capable of. The aesthetics on the other hand are down to personal preference and there will always be differences in these preferences. The addition of a splitter and rear diffuser would in my humble opinion, improve the looks by making it look less kitcar-ish and more finished. The Ultima is one of the finest looking kits available and incredibly capable to boot and lends itself well to personalised modification - provided of course that the execution is as good as or better than the concept.
Agreed, the standard chassis gets in the way af a good graound effects tray. I would love to see what they've don to the chassis of the above mentioned race car to get that tray to fit.
With the car at the factory ride height it puts up a large "rooster tail" in the rain. Someone on this board has paneled the engine compartment, wonder what effect that had.
With the car at the factory ride height it puts up a large "rooster tail" in the rain. Someone on this board has paneled the engine compartment, wonder what effect that had.
Indeed, the modifications carried out to the front end of the GTW have meant that it is no longer possible to open the clip on a hinge and I am not to fussed about this as it is not to large and cumbersome for me to remove on my lonesome but the rear clip is another matter. The problem that Pee rightly pointed out is the fact that the rear part of the chassis hinders an effective design for an adequate diffuser therefore I am considering lengthening the clip to allow more room for diffuser design. I am not sure about the look at the moment and do not want to upset the balance of the cars design to much if I can help it. All things considered, as has been correctly pointed out already, the car will see the road for 95% of it's duty time and so any performance advantage gained by said modifications will rarely be sampled.
You could hinge the front of a diffuser and have 2/3 mounting points at the rear with quick release clips so it would be a case of removing those 2/3, diffuser drops down and the rear canopy can still open on hinges.
It would have to be very very substantial though, not sure how many Ultimas ever see 180+, but the forces on it then would be enormous.
It would have to be very very substantial though, not sure how many Ultimas ever see 180+, but the forces on it then would be enormous.
You are right about not many Ultimas doing that speed although if it can be made to work efficiently, the diffuser should make a difference at 120+ which makes it more worth having than not. As for having to deal with a lot more 'force', I thought the idea was to straighten the airflow making it less turbulent and therefore stabilizing it at speed, can't see loads of force one way or the other causing to much of a problem so will speak to my man and get his views. The more I think about it, the more I fancy having the rear clip detachable in any case as if you need to open it, it is normally to work on the motor etc. and the clip being totally out of the way makes this so much easier. Even if the clip can still have some type of hinge system, I still want to be able to remove it for maintenance. I have just thought, I wonder if it would be possible to have the clip open by using some type of scissor effect hinge that will firstly lift the clip, say 150mm, and then hinge backwards from that?
Edited by GTWayne on Thursday 24th August 07:52
If you are worried about hinged ground clearance, why not hinge the front and rear clips at different points - some research as to what would be needed to clear wheels/exhausts/rads/chassis, but you can get some pretty trick mechanisms these days (Mclaren SLR for one). So the rear clip hinges on the roll cage upper mount points???
I'm planning to panel the floor on my car, I see that Canam Dave has done the same thing and I think someone in the US
The 2 triangle bars in a V shape
The Diffuser I made and fitted to my 7 was just amazing, you can feel the car being sucked to the ground when you go over 70-80. The drag effect you get on the back of a 7 will not be that bad in a Ultima as the rear is open for the exhaust and cooling.
But fix it down well mine “got sucked off” a few times.
I've worried about the heat build up under the rear clip so I am not sure about panelling the whole engine bay.
The 2 triangle bars in a V shape
The Diffuser I made and fitted to my 7 was just amazing, you can feel the car being sucked to the ground when you go over 70-80. The drag effect you get on the back of a 7 will not be that bad in a Ultima as the rear is open for the exhaust and cooling.
But fix it down well mine “got sucked off” a few times.
I've worried about the heat build up under the rear clip so I am not sure about panelling the whole engine bay.
Dr Peter said:
I've worried about the heat build up under the rear clip so I am not sure about panelling the whole engine bay.
I thought the engine was water cooled, not air cooled
It shouldn't be a problem if engine cooling is done as it is supposed to. If you have a heating problem and are on the edge to disaster then flooring the car may tip you over.
This season I have used my car without flooring or ground effect. This winter I will add. Splitter, flat floor and a venturi. I think it will make a huge difference.
I will construct a hinge system for both the splitter and the venturi.
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