Changing Front Wheel Drive Final Ratio??

[Mobrod]

Could anyone please tell me if it is possible to change the final ratio on the Toyota Corolla 1ZZ-FE or Sportivo 2ZZ-GE?

I would like to use one to build a wheelchair accessible clubman, with the Toyota Corolla engine in the rear. Although because the roof will be higher than original I'm thinking of using 20 inch wheels to give a more balanced look. This would increase the final gearing, which is why I'm looking for ways to change the final ratio.

Could anyone please tell me if this is possible and what ratios are available?

Thanks

[trd_st184]

You may find that the gear ratios (while using the celica gearbox as well) would be more than adaquate for the size of the wheels. I've seen quite a few ZZT231 Celica's running 18s or 19s pretty easily with no drastic change to the overall drive-ability of the car. Especially in a light chassis like the clubman.

[Mobrod]

Thanks for the suggestion, I've been wondering if it would be okay to just use the standard gearing. Using the online wheel calculator it says going from a 195/65 R15 to a 245/40 R20 increases the speed by 6.8%

[Sam_Q]

thats not really big, for example even going from a 3.9:1 to a 4.1:1 is a 7.9% change and not an overly noticable one at that. I also think you will be fine

[Mobrod]

Thanks, so I could even perhaps go bigger and 22 inch could be an option

[Sam_Q]

yeah you could, sounds unusual. So whats the calculator say about that size?

also keep in mind the lower the profile you go the more it "tramlines" and also bigger wheels are heavier and put more weight on the outside.

Hey do you have any pics of this thing?

[trd_st184]

I think a clubman already has a balanced look, even if the roof was made higher.

I would either make it convertible or stick under 16-17" personally. You would loose a balanced look with wheels that are too big personally. Not to mention that you may not be able to use the wheel covers front and back due to the huge wheel size which would look even more strange personally

[Mobrod]

The calculator says 255x35x22 increases the circumference 11.9 percent. http://www.miata.net/garage/tirecalc.html

It will be very unusual. A combination of space frame and chassis rails to keep everything light, but still a large open internal space. Headroom inside will be 1.5 m (legal requirement). The whole thing will be kept as low as possible. One door only, a gull wing on the passenger-side with a short ramp to enter the vehicle. Fiberglas body, touch screen console that is also voice-activated.

I only have a sketch of the finished vehicle at the moment. Still trying to raise funding for the prototype vehicle. They will then be built as a nonprofit organization to keep the cost as low as possible.

[Mobrod]

I agree, standard clubman's look perfect with the current wheels they have, my problem is the current clubman roof is approximately 1.1 m, mine will be approximately 1.6 m. The long nose on the standard also helps it look lower, my nose will be almost half the length.

[Hiro]

The calculator says 255x35x22 increases the circumference 11.9 percent. http://www.miata.net/garage/tirecalc.html

It will be very unusual. A combination of space frame and chassis rails to keep everything light, but still a large open internal space. Headroom inside will be 1.5 m (legal requirement). The whole thing will be kept as low as possible. One door only, a gull wing on the passenger-side with a short ramp to enter the vehicle. Fiberglas body, touch screen console that is also voice-activated.

I only have a sketch of the finished vehicle at the moment. Still trying to raise funding for the prototype vehicle. They will then be built as a nonprofit organization to keep the cost as low as possible.

This might sound a little strange, but have you looked at the Aussie Racing Cars? You're starting to lean away from the standard clubman format and more towards an ARC, which run a stumpy body-style, although they have the engine mounted at the front, and only 13" wheels (might give you an idea as to how the 20s would go in proportion

[roadsailing]

I think putting 20 inch wheels on would take it from looking odd to looking ridiculous. i wouldn't make the decision until you at least get some proper side on true scale drawings.

Could be worth using other visual tricks, like painting the roof black with a brighter body could help, nfi.

[Mobrod]

The Aussie Race Cars are pretty much the look I'm aiming for. Those things are tiny. I'm hoping it will look similar, just scaled up. I know it's not really a clubman anymore, it's just the easiest way to explain what we're doing. It will be the same length as the Toyota Corolla, just a little taller. The current dimensions are the smallest that we can go while still fitting the wheelchair inside. It will still be a lot smaller than the current vans.

That is a scale drawing. I drew a boxy scale model in google sketch it, then an artist friend added the detail and rubbed out the original 3-D boxes. I'll draw a scale two-dimensional side view this weekend.

[Hiro]

If you're after that kind of size (1.5m is same or lower than a lot of cars out there) and much shorter, then 20" wheels are going to be massively oversized. Probably something like a 17" would be the largest I'd go.

One problem is that hand sketches will never look like the real thing. You'll never be able to replicate just how the car sits on the suspension, and how the wheels and tyres flow with the wheel arches (and blend in with the shadows). Concept cars are a prime example of this, the sketches are usually with much larger wheels yet the production item is in much better proportion with smaller wheels.

The trick is the match the size of the wheels with the visual "bulk" of the car. It is this reason that a Golf might sit much better on 19s than a Corolla of the same approximate size, because the Golf looks a bigger car than it really is (and more "solid"). Or, in another approximation, imagine a humpy FX Holden running 19s, it just wouldn't look right.

[trd_st184]

I have to admit thats a pretty cool idea though

The sketch is pretty damn good, wish I could draw like that

[Mobrod]

Hiro, you're right the current Toyota Corolla is just over 1.5 meters high. Unfortunately that's the internal headroom we need, plus minimum 10 cm ground clearance plus approximately another 6 cm for chassis, plus another 3 cm for roof makes the car around 1.7 meters outside height, approximately the same height as the Toyota Hilux. I've been thinking around 18 would look right, although wheels are the last thing we will be looking at. I'm just checking now to make sure there are no problems in the future.

Thanks trd_st184. This will be the prototype. I'm hoping if it works so we can begin building them as a nonprofit organization to keep the cost as low as possible. Unfortunately it's a little tricky to get sponsorship for the project. Hopefully we will get funding soon, the car will be easily a lot better than a modified industrial van which is currently the only option. A friend of a friend volunteered to draw pictures. I think they turned out great, exactly how I was picturing the final vehicle.