Does anyone know the front and rear track width on the 818?

[veloce2]

Does anyone know the front and rear track width on the 818? If not care to guess

[PhyrraM]

Because of the reuse of the Hubs/knuckles, lower suspension arms, the steering rack, and the wheels. "Very close" to the OEM Subaru track width is my guess.

[veloce2]

Because of the reuse of the Hubs/knuckles, lower suspension arms, the steering rack, and the wheels. "Very close" to the OEM Subaru track width is my guess.

Not to be argumentative, but why would you think that?

[PhyrraM]

The steering rack has only a certain amount of adjustability. If the track width was outside of this range, FFR would need to either replace the tie rods (or the entire rack) to accommodate the new width.

There has been no indication that this is in the plan and the current version of FFRs "What you get and what you need" list specifically mentions you need to keep your OEM tie rod ends.

[veloce2]

Thanks That makes perfect sense

[wleehendrick]

The steering rack has only a certain amount of adjustability.

For the front obviously, but the rear could be wider since it's been stated that the kit will have new half-shafts, right?

[veloce2]

For the front obviously, but the rear could be wider since it's been stated that the kit will have new half-shafts, right?

Good point. Maybe thats what they are defining right now during testing.

[wallace18]

The half shafts have to be differant because you are use front inner cv and rear outer cv from donor. Front and rear axles are totally differant on the donor.

[veloce2]

But it does open the door to a different size than stock

It's interesting that Subaru has different track sizes on their cars between sedans and wagons etc.

[Vman7]

I went back and had to look at the orig. drawing that FFR gave out for the contest for the track widths, now whether that is still the same I don't know.

Here are the track widths from the contest drawings:

Front: 58.5"
Rear: 58.3"

[Seniorsub]

58.5" and 58.3" are the track widths for the WRX models from 2001 upto 2005 according the EUR. service manuals!

But the wheelsbase is not the same and this will create an Pro-Ackermann or an Anti-Ackermann!

greetings

[wleehendrick]

But the wheelsbase is not the same and this will create an Pro-Ackermann or an Anti-Ackermann!

Good info... I I had to google the term: http://en.wikipedia.org/wiki/Ackermann_steering_geometry

However, the Subbie is a 99" wheelbase vs 95" for the 818, so only a 4" difference (and commensurate shift in the steering pivot point relative to the rear tires)

[Samiam1017]

Wheelbase wouldn't have an effect on Ackerman

[Evan78]

Sam, you might want to double check that unless you're making an argument that the wheelbase change is too minor to have an effect. Wheelbase is a factor in setting Ackerman.

[Samiam1017]

I'm saying its two minor. I could see a big effect maybe if we were taking about stretching a vehical a few feet like limo builders. But a small change of maybe a foot (I guess we don't know the actual change) would be so minor.

[wleehendrick]

(I guess we don't know the actual change)

Yeah we do... 4"!

[metalmaker12]

lol... we should problem wait to see what the specs are? Assuming is getting us nowhere

[rjh2pd]

Is FFR giving us new hubs, our are we using the ones off of the donor? If they are giving us new hubs, the front track could change a considerable amount from the donor.

[PhyrraM]

To the best that I can tell from researching part numbers, Subaru uses the same ackerman geometery on cars with 99, 101, and 103 inch wheelbases. It's likely that the Tribeca (108") also uses a common front knuckle.

Very few cars have, or even want, "perfect" ackerman...or any other suspension design feature. Remember, all tires slip a bit which works to 'nullify' pefect settings.

[RM1SepEx]

Is FFR giving us new hubs, our are we using the ones off of the donor? If they are giving us new hubs, the front track could change a considerable amount from the donor.

use "front" donor inners and "rear" donor outers with a new Factory 5 axle to adapt between the two, so you could change width easily In the front you use the stub axle from the front donor axle assemblies, just remove the "guts" you can change the width as much as the tie rod ends allow, since they use the stock ones

so both front and rear could differ a bit from the stock Subaru, and some of the donors are different widths as well

[Seniorsub]

Good info... I I had to google the term: http://en.wikipedia.org/wiki/Ackermann_steering_geometry

However, the Subbie is a 99" wheelbase vs 95" for the 818, so only a 4" difference (and commensurate shift in the steering pivot point relative to the rear tires)


Only 4" will affect the toe-in/toe-out during cornering If you cornering with a wrong toe-in/toe-out you are loosing grip! For racecars we also taking the slipangles of the tyres into account and this is resulting in a certain amount of Anti-Ackermann or Pro-Ackerman. I am giving support to some race teams racing with similar concept of car (tubular chassis and Subaru midengines.

Conclusion: For streetcars Ackerman must be neutral!

[Erik W. Treves]

ok ... so now that we have reached a "conclusion", can we wait to see what the actual final product is, since nobody has actually seen it outside FFR....lol... back to cleaning parts for me...now what did I do with that popcorn....

[wallace18]

ok ... so now that we have reached a "conclusion", can we wait to see what the actual final product is, since nobody has actually seen it outside FFR....lol... back to cleaning parts for me...now what did I do with that popcorn.... Amen brother.

[PhyrraM]

ok ... so now that we have reached a "conclusion", can we wait to see what the actual final product is, ..........

Unlikely.

I find it amusing that one group basically says "Stop pleading for info. Let FFR do thier job, just talk amoung yourselves". And when that happens another group says "What's the point in speculating?". :p

[Evan78]

Unlikely.

I find it amusing that one group basically says "Stop pleading for info. Let FFR do thier job, just talk amoung yourselves". And when that happens another group says "What's the point in speculating?". :pMe too. I don't see the harm in speculation and contemplating the ramifications of what FFR may or may not do. There is still benefit in discussing possibilities.

[Xusia]

At the very least it's entertaining. Doing nothing while we wait is boredom defined...

[metalmaker12]

Lol, this is funny

[RM1SepEx]

They have already indicated that more info is forthcoming at Moochfest in less than 2 weeks...

[Scargo]

Has this ever been published? I see that now FFR is saying the wheelbase is 95 inches.

[flynntuna]

Has this ever been published? I see that now FFR is saying the wheelbase is 95 inches.

Road & Track did an article July 2013
Track, front/rear. 59.5/59.0 inches

You can read the article on the FFR web site.

https://www.factoryfive.com/wp-content/uploads/2014/01/rt-some-assembly-required.pdf

[metalmaker12]

Road & Track did an article July 2013
Track, front/rear. 59.5/59.0 inches

You can read the article on the FFR web site.

https://www.factoryfive.com/wp-content/uploads/2014/01/rt-some-assembly-required.pdf

Ditto a long time ago

[Scargo]

Well then, what are the FFR cars doing or anyone else that has "hit the tarmac" with their clothes on? Go-carting doesn't count.

Here's why I'm asking: I have been working on my front suspension design which uses a Honda S2000 upright. I am using some of the FFR upper control arm hardware but have gone to a Howe racing ball-joint. That's nothing in and of itself. It is mounted six inches lower on the frame than "normal".
The LCA is custom. With my 9.5 section width tires on 8" rims I am at a stance 1.2" wider than FFR's 210 slicks, yet I can only get to a 57" track width. I probably could run an ET of 55 instead of 49.
When I get to full bump (I consider that to be 2") I can manage a 20 degree wheel angle. That is all I can do, even with the front-end jacked up to +1/4 at the nose and 3/4" at the rear fender mount.
I guess what I'm saying is this puzzles me. I am starting with 2.2 degrees of negative camber and 5-6 degrees of caster. I have .6 degrees per inch of camber gain built-in.