RCR T70 Spyder Lightness

[Ron Earp]

Re: RCR T70 Spyder Lightness.....not bad

It isn't in the pan. Let me check. I didn't plumb that so can't remember off the top of my head. Clearly, it is either on the oil coming out of the motor or the oil coming into the motor.......but I'm not sure which.

Still, the cooler needs to be up in the air stream from the bodywork and right now it is a bit low. I can see on Johan's car that they have elevated the cooler to insure it is in the air flow.

R

 

[Johan]

Re: RCR T70 Spyder Lightness.....not bad

Going into the motor is where we aim for

 

[Ron Earp]

Re: RCR T70 Spyder Lightness.....not bad

Ron - Where is the sending unit for the oil temp? If in the pan is it close to the top of the oil level?

I had a quick peek at lunch and I'm pretty sure it is measuring temp coming out of the engine. I can easily swap it over to the other port and measure temp coming in. I actually have an extra SW mechanical oil temp gauge and might just put it on and measure temp out and temp in. We thought the temp going in was in the 240-250F range and we didn't like that one bit.

My Z has a cooler and thermostat for oil temp control and it runs right around 190-215F all day racing, even when extremely hot out side and I consider that about perfect. That coupled with a rock steady 185F engine coolant temp has lead to long lived motors.

R

 

[Russ Noble]

Re: RCR T70 Spyder Lightness.....not bad

ftp 16 BIAS PKY
rtp 18 BIAS PLY

Johan,

I take it those are cold. If so, what do they come up to hot?

Ron,

Great car, pity you didn't make the 13 hour though. But a big ask, straight out of the box to successfully complete a long enduro.

Cheers,

Russ

 

[Ron Earp]

It was something of a bummer to not make it but we were pretty close. Everyone involved put in a serious college try but it was just not to be. For instance, not 15 hours before it turned a wheel on track I had the engine torn down to the block replacing head gaskets and so on whilst tracking down a little water leak. If I had not gotten the flu I think we'd have made the race, but woulda shoulda coulda. Straight out of the box the car did great. We will make it in 2010.

Our alignment specs that we started with were:

Front
-1.7 degrees negative camber
+5 positive caster
Zero toe
Rack on inner steering hole

Once we collected some data we found the car was toed out at ride height after it'd been on track and settled. Too much camber for the front too.

Rear
-1.5 degrees negative camber
+7 positive caster
1/16th inch toe in

The rear felt pretty good, very nice and just needed to drop some camber to get it right. I like the 400 lbs springs in the rear, they were about right. So all we need to do is decamber a bit and adjust shocks, for the rear.

On the front we want to try a tad bit faster rack, a slightly different rack mounting position, less camber, and see how that strikes us.

As for tires and temps we're running ho hos and started them about 30 psi all around. With the light driving we did we didn't get them up to temp or pressure, but we weren't too far off either. Pressures can be fiddled with a whole lot more as well but until we get the front behaving exactly like we want all this info is gross data and just simple collection at this point.

Just got in the good 4.22 gear ratio for the box. Data shows we need that - the acceleration rate is insane in the car as the Traqmate data shows. You can't really feel it while driving because on track you just never know how fast you're going, plus, this is a new car, open top, new noises and so on. But on the data traces the car pulls very linearly from 80mph to 140mph, something that we're not used to experiencing. My Z can claw its way to 137 mph at Daytona, but this thing goes to a rev limited 140mph in about 1/2 the straight at VIR. The velocity curve doesn't roll over flat like my Z!

 

[Jac Mac]

My thoughts FWIW, reduce the rear castor. try to match it closer to the angle between floor/ground level and a line drawn between fwd end of lower radius rod & inner pivot of lower w/bone for minimal toe change at rear.

 

[Jeff Young]

It is beyond darty. It gets a left right oscillation in the front in high speed stuff that is spooky and hard to catch. Worse under power.

Whatever you guy sthink we need to do to correct that, we need to do. Car is fine by itself on track, well it's scary, but it's fine. It's not raceable as is. Moves around too much, under braking and high speed cornering.

But it is a ton of fun and "close."

 

[Johan]

We use nitrogen in the tires and they come up to 18 front and 20 rear. You said that you never got the tires up to temp and that is critical. If your tires are bias ply you are running too much pressure. Cold overinflated tires will drive as you have described.

 

[Ron Earp]

It is beyond darty. It gets a left right oscillation in the front in high speed stuff that is spooky and hard to catch. Worse under power.

Correct, but we were toed out, had bump steer, and have known issues to fix.

We're not running bias ply tires though, we use Hoosier's modern R6 compound that we're familiar with from running in SCCA IT.

I think we're close. We've got a new rack going in, suspension setup changes to make, and we'll have at it again. Looking forward to developing the car and racing it.

 

[flatchat(Chris)]

I had a heap of bump steer -- and we haven't driven it yet.
What poundage are the springs ? Heavy springs to control bumpsteer may not be the answer.
Your car looks good though, Ron :heart: --more pics of the front clip and how it is attached, etc pls.

 

just wondering why you went out with existing bump steer? so easy to fix. just now sorting a Formula Junior, criminal when a supposidly 'SET UP' car has 30 mm of b/steer per wheel over the shock range. but then i shouldnt be suprised any more. ive sorted conversions by experts that had 120, 140 and 150 mm total toe change on different cars. the owners wondered why they were hard to keep on the road. hell, the Mogan Plus 8 had factory bump steer. regards steve. ps , sorry , no progress on the lola but chris' conversion plate ls1 to g50/1 fitted a treat

 

[Ron Earp]

just wondering why you went out with existing bump steer?

Well, because we'd worked for many weeks getting ready for the event, had already missed two other test days, hadn't been able to drive the car at all, and this particular private test day before the event was paid for at $500 with no refund. The money was spent, we had the track time, we might as well go collect data - particularly when we're looking for issues bigger than bump steer, which is fixable. Bump steer is a minor issue in setting up a car but at some point the team says screw it, we're out of time, let's see what it does.

I don't know how much bump steer we have but it should be easy to adjust out using normal procedures, shim here shim there. Other cars in this configuration got down to zero with adjustment so I don't see why we can't. Once we start working on it I'll post here.

Chris, I can get some pictures of the front sometime this weekend or early next week. I've got a couple of cars to work on and clear out before getting back on the Lola. The TR8 is being prepped and sent off for some work, my Z needs brakes, corner weighting, and alignment, but once done it is done and put to sleep until 2010. I didn't write about it on the forum but the Z and I had a good year for 2009. Two wins, a second, third, and some lower place but still top ten finishes. Jeff pulled a 2nd place in the TR8 during the last race of the year (only race the TR8 got out in for 2009) so I think both of us will be well-positioned for 2010.

 

[Jeff Young]

Plus, honestly, we are motor and nut and bolt guys. We are just learning detailed suspension prep, and we didn't check bump steer. We'll get there.

That car is fun. I watch the video sometimes and remain amazed at the acceleration vis a vis our IT cars. The IT cars presently corner faster, but once we get the Lola fixed that will change!

Ron done good getting that thing. I like the open cockpit -- much better for on track in a car like that than the GT40 I think.

 

[Ron Earp]

Plus, honestly, we are motor and nut and bolt guys. We are just learning detailed suspension prep, and we didn't check bump steer. We'll get there.

Oh, I'd say we're a bit better than nut and bolt guys but for sure we're much better with motors, brakes, and so on than fine suspension tuning. But, some of that is due to our on track experience - it is hard to focus on the fine points to your car handle when your engine is missing on two cylinders or your brakes are failing. That will change for 2010.

Still, bump steer isn't hard and no different than any of the other alignment stuff we do. But we had to choose between fixing say a cooling system that blows caps off and water in the oil, or bump steer - one will keep you off track entirely while the other will make your driving difficult. You makes your picks and takes your chances.......

Ron done good getting that thing. I like the open cockpit -- much better for on track in a car like that than the GT40 I think.

Be careful saying stuff like that on a GT40 forum!! You definitely have a lot more room in the Lola than a GT40, but you need to try a GT40 out first. They're a blast.

 

[Jac Mac]

Im surprised it got a Ford in It, with Mr Youngs preference being all things Mopar it might end up with a Hemi, that would fix the bum steer, dont get much when the suspension travel is bottomed out full time..

 

our jac, i do believe you are inferin the hemis are big ass heavy. sorted the formular junior today. it would seem a few changes heve been visited on the front end, one of which was a wad of packing to the top arm to give some pos. castor. i'd say the engineer forgot that this drops a rear steer steering arm ht. and f-- up the arc. all well now , corner wts. tomorrow. regards all steve

 

[Jeff Young]

Jac....hmmmmm...I think I'd go with a nice light ally 340 block, maybe 400 hp, and 350-400 lbs.......yes....and some torsion bars for the suspension! lol....

That car (Ron's) is FUN. I'm not a Ferd guy, but even this detuned Stang 302 sounds really, really good and has a ton of power in this chassis.

I was dubious of the car as a track toy/race car but it's got a lot of potential. It's just so unstressed........the speed is ferocious without working extraordinarily hard at it.

 

[Ron Earp]

Your car looks good though, Ron :heart: --more pics of the front clip and how it is attached, etc pls.

Hey Chris,

Here is how the front clip is attached and it works extremely well.

The major alignment and weight of the clip is borne by the plastic biscuits mounted there on the ally pieces forming the front scuttle. The biscuits mate with cutouts in the clip that are beefed up with 1/4" derlin (or some sort of polymer).

The clip also plugs into the rest of the car using a male/female pin system. I've shot some pictures of that too. Then two clips snug the clip up but with the three pins and the two biscuits it is located very well and the clips do nothing but provide a bit of force to keep them from coming apart.

Hope these help.