Suspension setup/Tyres. What have you got?

[ACHiPo]

Originally Posted by RockBit

My ERA 427 with aluminum 482 weighed 2460 with a full tank, no driver, on certified scales.

Wow that’s pretty close to ERA’s number, which I thought was optimistic. With my cast iron block it should be about 100 lbs heavier, so about 2560.

[DanEC]

I'm running MT STs in 255/60 rear and 215/70 front. I went with the 70 series up front to stay close to 27 inch diameter to fill the front wheel well. They are about as tall as will fit on an ERA in front. They seem like real good tires although I can't say I've pressed them a lot.

Evan - can't remember if you went with an aluminum block or iron block - with an iron block I think you will be around 2650 - 2700 lbs or so. With an aluminum block Rockbits weight sounds about right to me. your undercar exhaust might weigh a few more pounds but you will probably save a few pounds in wheel/tire weight.

[ACHiPo]

Originally Posted by DanEC

I'm running MT STs in 255/60 rear and 215/70 front. I went with the 70 series up front to stay close to 27 inch diameter to fill the front wheel well. They are about as tall as will fit on an ERA in front. They seem like real good tires although I can't say I've pressed them a lot.

Evan - can't remember if you went with an aluminum block or iron block - with an iron block I think you will be around 2650 - 2700 lbs or so. With an aluminum block Rockbits weight sounds about right to me. your undercar exhaust might weigh a few more pounds but you will probably save a few pounds in wheel/tire weight.

I've got a cast iron BBM block. BBM lists their aluminum block at 125 lbs, and their cast iron block at 250 lbs.

[not-a-number]

Thanks for the replies. I think I am going to go on the skinnier side of things. Since its a light engine (relatively) and I dont have much power.

MTs 255/60 and 215/70 look like a good option. Maybe 235/60 on the front.

Shell Valley has given me their suggested road setup. Spring rate, F350 R225 so that will be the next thing to look at after changing tires.

[cycleguy55]

Front Tire Width: 245/60R15
Rear Tire Width: 275/60R15
Camber: -0.4°
Toe (in/out): 0.18°
Caster: 3.8°
Front Spring Rate: 465 lbs/inch
Rear Spring Rate: 300 lbs/inch

Car: West Coast Cobra
Wheelbase: 96"
Weight (approx.): 3,000 lbs.

[DanEC]

Originally Posted by not-a-number

Thanks for the replies. I think I am going to go on the skinnier side of things. Since its a light engine (relatively) and I dont have much power.

MTs 255/60 and 215/70 look like a good option. Maybe 235/60 on the front.

.

It (215/70s up front) actually looks better than you might think but it's probably not everyone's favorite. You can decide for yourself.

[Whodeeny]

How does one figure out the minimum (or maximum) rim width allowable for a given tire size? I have 7.5" Sunburst wheels going on my ERA that is in production now and was wondering what my options are. My preference is to make all 4 tires the same size as I will also be caring a spare.

[Alfa02]

@DanEC I like the look better then my 235-60-15 (front) that will go on my 427 street car, I'll leave those on for now as everything is new, but like the idea of your 215-70-15, right stance and I'm only 20mm wider on the back (275) . A very handsome car, Dan. It just reafrim's that going with a dark color (BRG) was the right choice with my street car too.

[cycleguy55]

Originally Posted by Whodeeny

How does one figure out the minimum (or maximum) rim width allowable for a given tire size? I have 7.5" Sunburst wheels going on my ERA that is in production now and was wondering what my options are. My preference is to make all 4 tires the same size as I will also be caring a spare.

Tire manufacturers provide charts that show minimum and maximum rim widths, plus they also usually show which width rim was used for measured specifications. Like this chart from Avon: CR6ZZ | Avon Motorsport

[strictlypersonl]

Originally Posted by cycleguy55

Tire manufacturers provide charts that show minimum and maximum rim widths, plus they also usually show which width rim was used for measured specifications. Like this chart from Avon: CR6ZZ | Avon Motorsport

tirerack.com has that information. Select a tire that you think might fit and look in the Specs tab. i.e.
https://www.tirerack.com/tires/tires...omCompare1=yes

[Dominik]

Front Tire Width: 235/60R15
Rear Tire Width: 275/60R15

Camber front: -0.5°
Camber rear: -0.75° (less camber in the rear than front would lead to oversteer)
Toe (in) front: 1,5mm per wheel (toe out leads to better turn-in into corners, but less straight line stability - enjoyable in the mountains)
Caster: 3° (not the most critical measurement. Make sure left and right are the same)

Toe (in) rear: 1,5mm per wheel (less powerful cars can use less because the rear deflects less). Never toe-out.

Front Spring Rate: 450 lbs/inch (ride comfort is defined by front spring rate)
Rear Spring Rate: 560 lbs/inch (this depends on your ratio) Too hard rear makes the car oversteeer

Car: RAM LR Roadsters (UK) with Jag XJ6 Suspension parts
Wheelbase: 90"
Weight (approx.): 2,000(!) lbs.

If you can, go on a track with a tyre pyrometer and measure temperatures after a few laps.

More: Tune to Win, pg 42 ff, C. Smith