99c5vert

16" wheels on the street is nice... you can't find bigger than 225 for 15" wheels.

Most Sevens go with 15" street and 13" track wheels.

sb427f-car

Hum, ok.

The biggest thing that I need to solve is the front suspension and work from there. Obviously picking a wheel and tire combo for tracking/auto-xing and then "living" with that suspension on the street.

What brake options am I looking at with the 13" wheel option. I'm assuming that when you size up track tires for those applications most of the time they'll end up as tall as the 15" low pros.?

99c5vert

the 13" with racing slicks don't add up to 15" low profiles... the overall diameters are smaller. Typically the cars lose ground clearance and gain in gear ratio on the 13" slicks.

You don't need a super stiff suspension necessarily. I made that mistake, and may switch to softer springs down the road. Adjustable shocks will help with ride quality (street vs. track) too.

The thing about sticking with smaller wheels and brakes is the weight savings... those are rotating unsprung parts, so weight savings there REALLY matter.

Mine uses front uprights from a 74 Toyota Corona Doesn't sound very impressive, but it does the job.

sb427f-car

Hum, ok.

I'm thinking about going inboard on the shocks to help with the unsprung weight issue. I'm marginally concerned about a rough ride (in that if I had fillings, I'd still want to have them).

I realise about the loss of ground clearance and gain in gear ratio (already thought about both of those actually). Fortunately, I have a few buddies that are Mech Es and I remember enough from when I was one to work on getting things done right.

I saw were someone basically fabbed their own upright out of round tube and bar stock.

EDIT: Another shot...

99c5vert

nice setup on the upright...

my old rotus has inboard front suspension. if I were designing it, i'd keep it outboard. unless you're going to super small shock spring package, you won't save anything (remember the extra tube and rocker arm).

also, inboard creates a packaging issue, and makes it a little harder to adjust shocks.

The main advantage of inboards is aerodyamics - which is pointless on a 7

99c5vert

do you have a link to a thread about that upright? i wonder how he did the bearings.

chuntington101

that looks a nice set up but i think inbounds are a little ott unless its an all out racer! a nice outboard set up will work fine. also as said before, let you have good acsess to the shock/springs.

thanks Chris.

99c5vert

Aaron, also, on designing your upright, it's probably more desirable to put the front calipers behind the center line of the wheel, half way up... lower center of gravity and lower moment of inertia (for the car) than the setup shown... If you look at most performance cars, you'll notice calipers are towards the middle of the car (front and rear)

sb427f-car

haha, I actually snagged that off of whittlebeast (from the usa and uk boards). It's from his A Mod cart. Hey, I'm not here to reinvent the wheel, just trying to cover ALL my basis. Unfortunately, I don't have shots to see how he did his bearings and spindles.

As far as brakes, yes I know what you mean about trying to get your weights as central as possible.

True on the inboard shocks...eass of getting to for adjustability is more important than weight to an extent.

sb427f-car

I've found one on eBay from a private seller with trans...fairly local (VA). This is becoming tempting.

99c5vert

eBay is the enemy of my savings account

sb427f-car

Seriously. I'm REALLY questioning if I should buy it or not. It's just gonna sit around for right now, but if I get it, then I'll be more tempted to build this sucker.

I'd really like to pay my car off (which I could do today if I had or wanted to). ugh, the decisions of life.

sb427f-car

Ok...so I put off buying any parts (probably good decision), over priced paper weights is all they'd really be.

I wanted to update this thread with books and what not...

Currently reading competition car suspension, a practicle guide, 4th edition by Alan Staniforth.

I have a few others to get to: Engineering to Win: Racecar Dynamics, Chassis Engineering.

If anyone else has some good race prep books, I'd love to know about them. Same goes for frame deisign.

BanditTA

iTrader: (3)

Use a L67 (SC 3800) from a Regal GS or Grand Prix GTP lots of the J-body guys drop those into their cavys and are running low 12's. Cam and intercool the 3800 and your into the 10's.

sb427f-car

Almost as heavy as the LS1/T56 combo from all my reading thus far, besides, you pay the same weight penalty for the displacement multiplier of the boost in SCCA solo rules.

chuntington101

i still think supercharged ectoec. get it making 250+bhp and get the weight as you can! alternatively go bike power and a turbo 350bhp and you get a 6speed sequnetial box to boot!

its tried and tested to work and work VERY well!

Chris.

sb427f-car

Bike engine = classed in SCCA auto-x A mod (top dog class), and not something I want to get mixed up in. The more I think about this build...the more I see rat rod meets ledgendary sports car.

sb427f-car

Hum, here's a bump for someone that asked about a Stalker...


Re-reading this has refocused me as well...man, how plans quickly change or get lost in the muddied waters of over planning.

chuntington101

hey sb427f-car. hows it all going with the 7 design/planning???

Chris.

chuntington101

...oh and heres a couple of pages for you to have a look see at.

http://www.zcars.org.uk/mini/index.htm

& the spacefreamed version....

http://www.zcars.org.uk/montecarlo/index.htm

Chris.