Chassis differences
Discussion
Apologies if this question has been asked before (I did look through the last 25 pages!)but .....
Are there many differences over the years between the chassis of the Sports and it's successor the GTR. In particular are you limited in what you can fit (engine, gearbox, suspension, steering, brakes etc) to each version ? Also if there are limitations, does the factory still make the parts for the 'old' versions.
Cheers,
Chris
Are there many differences over the years between the chassis of the Sports and it's successor the GTR. In particular are you limited in what you can fit (engine, gearbox, suspension, steering, brakes etc) to each version ? Also if there are limitations, does the factory still make the parts for the 'old' versions.
Cheers,
Chris
I doubt anyone here can answer all the questions apart from the factory.
Yes the chassis has changed but what are you trying to achieve?
The factory will ask the same as there is little point listing all the fine points of say door hinge locations if all you wanted to know was can I fit bigger brakes or replace a Renault transaxle with a Porsche.
Steve
Yes the chassis has changed but what are you trying to achieve?
The factory will ask the same as there is little point listing all the fine points of say door hinge locations if all you wanted to know was can I fit bigger brakes or replace a Renault transaxle with a Porsche.
Steve
OK sorry to be so vague...
Like (I assume) a number of people who who like to build an Ultima, the cost stands in the way even if spread over a year or two.
There are around a number of 'older' cars at variety of 'needs completing' or 'partly rebuilt' stages - you get the idea. In theory these offer a route into building your own personal Ultima at lesser cost - maybe !
My question therefore is are these cars a false economy since they are limited as to which engine/transaxle/brakes etc that can be used. I don't have a need to have the latest version but I'm not sure about having to use non-chevy engines or renault boxes. (please no flame wars).
As you say there are probably too many ifs and buts without knowing exactly which version is on offer, still like to know about any obvious gotchas.
Many thanks,
Chris
Like (I assume) a number of people who who like to build an Ultima, the cost stands in the way even if spread over a year or two.
There are around a number of 'older' cars at variety of 'needs completing' or 'partly rebuilt' stages - you get the idea. In theory these offer a route into building your own personal Ultima at lesser cost - maybe !
My question therefore is are these cars a false economy since they are limited as to which engine/transaxle/brakes etc that can be used. I don't have a need to have the latest version but I'm not sure about having to use non-chevy engines or renault boxes. (please no flame wars).
As you say there are probably too many ifs and buts without knowing exactly which version is on offer, still like to know about any obvious gotchas.
Many thanks,
Chris
OK.
The older cars you will be looking at will probably be Rover V8 and Renault transaxle. There is nothing wrong with this arrangement and there are many who prefer the sound from a Rover over that of the Chevy.
If you are not looking for top performance then stay with that and do any additional tuning you want.
The chassis and suspension has not changed much in terms of ability it just has brackets and mountings moved about.
The brakes may be Ford Granada and do a fine job for most people but if you want to stop from a ton in 3.5 seconds then you will need to upgrade. Not sure what fits because I think early cars had smaller rims so may not take the current AP brake upgrade.
In terms of spare parts, Ultima is pretty much a 'hand to mouth' organisation and even the current parts are only made in small batches so there is no reason why the part you want cannot be made or an alternative sourced.
Even though I have a GTR I still like the earlier models and they will turn heads in much the same way.
Enjoy
Steve
The older cars you will be looking at will probably be Rover V8 and Renault transaxle. There is nothing wrong with this arrangement and there are many who prefer the sound from a Rover over that of the Chevy.
If you are not looking for top performance then stay with that and do any additional tuning you want.
The chassis and suspension has not changed much in terms of ability it just has brackets and mountings moved about.
The brakes may be Ford Granada and do a fine job for most people but if you want to stop from a ton in 3.5 seconds then you will need to upgrade. Not sure what fits because I think early cars had smaller rims so may not take the current AP brake upgrade.
In terms of spare parts, Ultima is pretty much a 'hand to mouth' organisation and even the current parts are only made in small batches so there is no reason why the part you want cannot be made or an alternative sourced.
Even though I have a GTR I still like the earlier models and they will turn heads in much the same way.
Enjoy
Steve
Chris,
I've had similar thoughts for a winters project, probably next year (or even the year after) now.
The main boxes I've seen have been renault or the G50, obviously huge difference in price. One other that may be worth considering is the twin bike engine option, although some fairly serious engineering will be required (see the z-cars website IIRC)
Are there any other (cheeper) options than the G50 for taking a bit more power ?
I've had similar thoughts for a winters project, probably next year (or even the year after) now.
The main boxes I've seen have been renault or the G50, obviously huge difference in price. One other that may be worth considering is the twin bike engine option, although some fairly serious engineering will be required (see the z-cars website IIRC)
Are there any other (cheeper) options than the G50 for taking a bit more power ?
cjt said:
Steve,
Thanks for the reply, are there any issues with the renault transaxle ? Presumably it is much more limited in the power it can handle.
Does anyone know if a chassis designed for the renault box can be modified for the G50 ?
Cheers,
Chris
The Renault 'box is not as strong as the Porsche but the Rover V8 is not as powerfull as the Chevy so they are a good match.
I believe the weakness is the input shaft and that most of that comes from poor tolerancing of the adaptor plate causing miss alignment. This comes from other car installations (possibly GT40 replicas). I am not aware of the same issues with Ultima install and would not expect it considering their engineering standards elsewhere.
I believe there are companies offering input shaft upgrades.
Steve
Try this link www.bell-performance.co.uk/ for a UN1 problem rundown. It is his explanation of the problems with the Renault box in high torque applications.
Phil
Phil
The Lotus Esprit is a good example where the Renault transaxle was fitted and it's limitations exposed. The history can be traced back to the late 70's when the Esprit engine was making around 160BHP. The gearbox was pretty happy in this environment - in fact it seemed to cope pretty well with most of the 4 cylinder engine derivatives through to the mid 90's.
There were known limitations however and the input shaft could flex and whip, causing failures and 5th gear can shear off completely under some circumstances. Lotus themselves programmed the ECU of the V8 engine to reduce the amount of 1st and 2nd gear torque available so as not to over-stress the gearbox. Many owners have suffered failures however and it's probably not the right choice for a high torque V8.
The Ultima Sports MkIV will take the chevy/porsche transaxle and these cars might make sense for the kind of project car you are looking for.
Cheers,
Dave.
There were known limitations however and the input shaft could flex and whip, causing failures and 5th gear can shear off completely under some circumstances. Lotus themselves programmed the ECU of the V8 engine to reduce the amount of 1st and 2nd gear torque available so as not to over-stress the gearbox. Many owners have suffered failures however and it's probably not the right choice for a high torque V8.
The Ultima Sports MkIV will take the chevy/porsche transaxle and these cars might make sense for the kind of project car you are looking for.
Cheers,
Dave.
canam-phil said:Cheers great read
Try this link www.bell-performance.co.uk/ for a UN1 problem rundown. It is his explanation of the problems with the Renault box in high torque applications.
Phil
So it seems I could get a nice MkI with 450-500 happy power at a reasonable cost

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