help with "new" race car
 

I have a late model race car that I am converting to track car.
got it on the track for the first time a few weeks ago.
I was expecting front end problems, mostly understeer but the rear end was extremely loose. both going in turns and coming out.
I took weight off left side, so far 170 lbs.
weights:
left side- 1375
right side-1300
front-1350
rear-1320
(full tank of gas) me not in it.
the ROLL CENTER for the rear is offset to the left about 4 inches due to a watts link
. (have not measured it since I thought the front would be an issue and I have not started on the rear yet).
the car did seem to feel a little better in the only 2 left hand turns.
it felt easier to control when the rear end kicked out in RIGHT hand turns vs left hand turns if that means anything.

since it did feel somewhat better in the left hand turns I was thinking about putting just ONE softer spring on the left side.

I do have the 170LB of weight I will probably put back on the right side along with moving the battery over to the right. the car is only about 2600 lbs right now,.


what do you think, softer spring on the left rear.
the reason I say change just one side is that I was going to order softer springs anyway and the RC is offset. also read that having a stiffer spring on one side moves the RC to that side.

I was able to drop the center link of the watts link about an inch to lower the RC.
I have 200lb springs in the rear, was going to order 175.

the only other way to move the RC back to the center of the car is to put on a pan hard bar.

On a gocart that I designed, and built for dirt track racing about 20 years ago, I set the right side rear axle bearing hanger 1/4" rearward to help it turn left. This was non-adjustable, and built in for turning left. I also had different castor settings for the front wheels with the thinking that on left hand turns, the inside tire/wheel had to make a tighter turning radius than the outside tire wheel....only a few degrees difference was a big deal in dirt track racing.

The mod that I used the most was an adjustable FR spindle that I could lower for more push, or raise for more loose. Is it possible that some of these "mods" are present in your race car ?

If you pushed this cart across my barn floor, it would make a long arcing left turn.

Maybe not enough information, are you off the breaks at turn in (ie not trail breaking)? How’s your throttle application, are you too much gas too soon? The left hand turns where the car felt better high or low speed turns as well as when the car felt easier to control when the rear kicked out in right hand turns vs the left hand turns were you able to kick the rear out in those turns (left hand)? So often we want to change something on the car because it just can’t be how we the driver is driving it (I’m guilty) - I swear I am flat to gas all the way to the end of the pit wall drivers left heading to turn 1 at road Atlanta, I just know I am. My data system will show, oh never mind, looks like I the driver has more work to do before we go throwing a bunch of new stuff at the car.....

Is this dirt or asphalt?

only had 2 lefties. one was fast, around 100, the slow and really 2 turns with a decreasing radius.
i did not push the fast turn as i was just learning the car and it was so lose.
the slower was lose going in but more some coming out, of course on the gas.

i think trail braking.
not a lot of hard braking on this track except front straight, yes one time i did a nice 4 wheel drift right to the outer edge then dropped the rear off getting back on gas.....lightly.

how much do you think the offset RC effects this.

I added 100lbs to the right rear just in front of the tire.

so what about the RC being offset to the left by 4 inches.
is that something i need to fix.

You running Roebling it looks like from you photo? That track is all about being patient, hows your line coming into and out of turn 6? Can you get WOT by the dirt access road drivers right in the long right hander and keep it WOT to the accelerate to point for turn 1? That track also eats tiers by lap 4 on stickers plan to start managing skid and that’s in a 2400lbs 125hp Miata, I am sure your car maybe even less laps.

yes it is!!
it was a good track for debuting the car to road racing. long turns to let the car settle and feel what its doing

turn 6 was not too bad.
it was pretty slippery though, especially midafternoon when it was really hot. WOT out and to the last turn, then just a lift through the last on and out to the rumble strips.

I felt most confident in the last turn and the fast left hander, turn 3.
probably turn 5 was the trickiest due to braking and turning,
I could have gotten more out of turn 1

turn 4 and 6 was the loosest for me. I dropped 2 wheels between 1 and 2 but I was just too fast in.

you going to CMP next month?
there a re 2 events there next month.
getting some other issues worked out on the car.
insulated the fuel line in the engine bay,
cleaned and set points and dwell. so easy on a dual points dist.
need to relocate fuel pickup in tank. It is in the worst place it could be, right front.
my tank is not level so I will move it to the center rear.
I think I had fuel pickup AND ignition issues at RR.

going to order softer rear springs if I go.
still only running 2 gears since I don't have the shifter installed yet.

Your race car looks like fun at the track and at home while working on it in the garage.
Any video of your test day?

Imagine how much safer you are in a fully caged car with safety equipment, fuel cell, fire system and race seat compared to the fast guys with production street legal sports cars.

Perhaps after your shifter is working you will find improved car control/weight transfer control.

How's the brake bias?
A little more bias to the front might make the car easier to catch.
I prefer to left foot brake my car for added weight transfer control.

Simple stuff like be prepared for a flat tire by keeping fuel lines or oil lines and filters inboard of the frame rails away from a delaminating slick.

If you are on a budget try some tire softener treatment to restore the grip on old slicks.

Everyone in the pits say they can help and they will take your money but only a few actually know how to make your car better.
If you can find an experienced expert your car will be more safe, easier to drive and faster.
I've had a couple of very helpful driving and set up mentors.
Last year I sold my 911 RSR to free up more fun time with my Camaro Trans Am spec race cars.

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oh man, that one looks like fun!!!!!

much newer than mine and probably easier to convert to road course if it was a circle track car like mine was.

my father in law built this one back in the late 80's. very much designed for left turns only!!
had to change out oil pump and oil pan for one.
a big one is the upper A arm mounts.
the left side is set for less camber and less caster compared to the right side.
I can only get about 2 degrees neg camber and 2-3 caster on the left where I can get 5 -6 degrees camber and 5-6 caster on the right side.
I have new mounting plates but would need to pull the engine to put it in plus its not a purpose built chassis. that is it has a 69 chevelle chassis that the roll cage is built off of.
no passengers seat so that was a biggie since a lot of track days require an in car instructor. thanks to covid not any more!! just to bad my wife cant ride.

finally something I can plat with at the track, make suspension changes and see how it drives!!!

these are the way to go for the track. cheap and easy to work on.

great looking car!! looks like fun.

Not exactly designed for road racing but works for circle track.
My father in law was very frugal. But his cars were safe, well built and won.

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