Why Are Spec Racer Fords So Loose?

I was watching another in-car video from a Spec Racer Ford and it was consistently loose.  I've always heard that SRFs can be twitchy.  But most importantly that to set up the cars fast they have to be set up loose.  Said another way, all the fast guys set up their cars loose.

Why is that?  Why is loose fast in a SRF?

I understand setting up a front-wheel drive car loose to be fast.  But the SRF is mid-engine.  I don't know the weight distribution but I'm guessing it's weight is rear-biased.

"Normal" setup theory is to get all four tires working equally.  Why would a loose SRF get slower with a little less rear sway bar?

[I am not talking about driving style.  I am also not talking about over-correcting for an understeering car.  Fast SRFs are just plain loose.]

I didn't watch the whole video but a little over a lap from where you started it. The only moments I would describe the car as "loose" were the times he took a super tight entry into the long fast corner after the banked straight to pull off a pass. Everything else looked pretty neutral, especially for a mid engine car.

Nothing to offer other than I want to make a SRF street legal and drive around in it...

OldGray320i (Forum Supporter) said:

Nothing to offer other than I want to make a SRF street legal and drive around in it...

What would it need, lights and a horn? 

Might be too low though, I remember they had a problem with the CRX when it came out because the headlights were not high enough off the ground.

Bias ply tires? How old is that vid? A quick google has discussions in 2018 about the "new radials" being better than the bias ply. 

It does seem like the driver was pushing the limits quite a bit playing catch up and the 1,2,3 battle had a lot of driving slightly past grip limits so could it just be that?

Toebra said:

OldGray320i (Forum Supporter) said:

Nothing to offer other than I want to make a SRF street legal and drive around in it...

What would it need, lights and a horn? 

 

Might be too low though, I remember they had a problem with the CRX when it came out because the headlights were not high enough off the ground.

Ummmm... no such thing as too low.  Speed bumps and road imperfections are too high - really something our society needs to address once this pandemic madness is over.

I thought this was going to be about people who drive spec racer Fords, I am less interested now.

No, the camera car in that video really >is< loose.  Just as an example, around 12:30 he comes off the oval into a long, fast left-hander.  I count at least five counter-steers in just that one long turn.  That car is capital-L Loose.

DWNSHFT said:

No, the camera car in that video really >is< loose.  Just as an example, around 12:30 he comes off the oval into a long, fast left-hander.  I count at least five counter-steers in just that one long turn.  That car is capital-L Loose.

It may be loose, but it seemed pretty controllable.  It's not like the hands were flailing all over the place- all of the drifting was well controlled.

I've only experienced the iRacing version, but they are definitely loose by default. I think the weight distribution is really far back, even for a mid-engined car.

OldGray320i (Forum Supporter) said:

Toebra said:

OldGray320i (Forum Supporter) said:

Nothing to offer other than I want to make a SRF street legal and drive around in it...

What would it need, lights and a horn? 

 

Might be too low though, I remember they had a problem with the CRX when it came out because the headlights were not high enough off the ground.

Ummmm... no such thing as too low.  Speed bumps and road imperfections are too high - really something our society needs to address once this pandemic madness is over.

People don't see normal sized cars. 

My NA Miata lowered on RComps, my eye level was about the bottom of the door on modern trucks. 

No thanks.

DWNSHFT said:

No, the camera car in that video really >is< loose.  Just as an example, around 12:30 he comes off the oval into a long, fast left-hander.  I count at least five counter-steers in just that one long turn.  That car is capital-L Loose.

The point you referenced is the only point along the lap where I would consider the car at all loose. But remember that that's a long, high speed corner, and he's entered it super narrow and carrying a ton of speed to make the pass work, so it's not super surprising that it's a little loose in that situation. The rest of the lap is "neutral with a touch of oversteer" at worst, combined with driving at the limit.

Edit: in an attempt to answer your actual question, I'd guess because loose is fast in rwd cars too as long as it's controllable. And SRFs are notoriously very controllable at and just beyond the limit of grip. Tires are radials as far as I can tell but they have giant sidewalls so there's probably a decent amount of compliance there even for being radials.

The easy answer to this question is because "loose is fast, it just is is" ask Schumacher & Hamilton

The longer answer:

 First the camera car appears to be running a good bit of rear brake bias and chucking the car into corners to close up the gap in tighter sections. If the tires will hold out you can make up a car length and be back on the gas earlier.

They are on skinny tires 185/60-13s, I used to use the same tire on the Datsun, and they are 1500lb cars so from a chassis standpoint they are under tired. Note I've since gone to a Hooiser tire so the size might have changed in the last several year but regardless they are still on skinny tires. Also note they've always used a treaded radial tire. 

They are low powered, so as with any low powered car on  skinny tires, you can set them up loose because you don't have really have an issue with putting the power down on exit like you would with a GT-1 car.

With a loose car you are winding in less steering and as a result there is less rolling resistance, additionally you'll be on the gas sooner.

I tend to set up a car so you can rotate it aggressively on the brakes and then balance it with throttle through mid corner to the exit. By contrast I have a friend who does the same thing by setting a car up with trailing throttle oversteer.  I find the latter method to be harder on tires plus if you are trying to out braking someone deep into corners if doesn't give you a lot of options.

The quicker it changes direction the quicker you can go back to full throttle. It essentially gives you more options as a driver. What if you were slowed by traffic and now want to transition through a corner? Especially critical when close, hard fought racing means less racing the perfect line. Jcamper

That looked like a ton of fun, but I cringed at all the "love taps," especially the one done as the leading driver was beginning a turn. Is that kosher in SRF?

In reply to dculberson (Forum Supporter) :

It was certainly pretty common when we went to the Runoffs at Indy in 2017, and it was a huge field. It made braking into the first turn entertaining for us spectating.

In reply to DWNSHFT :

Why are you afraid of loose?

  I'd much rather have a car a little on the loose side than under steering. 

You can use that looseness to get a faster lap time.  You can also use a loose car to position yourself to take a corner away from a driver who is coming in too tight. 

frenchyd said:

In reply to DWNSHFT :

Why are you afraid of loose?

  I'd much rather have a car a little on the loose side than under steering. 

You can use that looseness to get a faster lap time.  You can also use a loose car to position yourself to take a corner away from a driver who is coming in too tight. 

 

I never said I was afraid of loose.  I like a car that is willing to rotate.  I just want to know why SRFs want to be so loose.

dculberson (Forum Supporter) said:

That looked like a ton of fun, but I cringed at all the "love taps," especially the one done as the leading driver was beginning a turn. Is that kosher in SRF?

I raced spec racers for ten years, it can be kind of like a Roman chariot race out there.    Sometimes the only things missing when entering the first corner were whips and spikes sticking out from the wheels.  They are pretty durable cars and they can stand up to a lot of abuse.

As for whether they're loose, I think that just has to do with how that particular car is set up.  I have watched that video before, and that guy was driving right on the ragged edge (after all, he was going from 25th to 1st place, in a race where all the cars are pretty equal.)

DWNSHFT said:

No, the camera car in that video really >is< loose.  Just as an example, around 12:30 he comes off the oval into a long, fast left-hander.  I count at least five counter-steers in just that one long turn.  That car is capital-L Loose.

It may also be that he's over driving the car.  I've intentional done that on occasion when the circumstance calls for it.  A lot of time when you're racing against cars with similar speed you may need to set up a pass a lap or more in advance, forcing you to be at a certain place on the track when you anticipate events to happen. 

Example; you anticipate the car ahead of you to lap a back marker at a particular turn. If you can be where he wants to go to make that pass that will force him  to brake while you're on the throttle.  

I've  driven both momentum cars  ( like a Spec Ford  would be) and inertia cars ( powerful cars like Corvettes)  momentum cars need balance and smoothness.    With inertia cars while that works best for setting lap times.   During  the actual race you need the aggression, looseness or the ability to induce looseness  can give you. 
Remember if you are on the inside of a turn you can control how and where the other driver has to go. 

Tom1200 said:

 

The easy answer to this question is because "loose is fast, it just is is" ask Schumacher & Hamilton

Or legendary crew chief Harry Hogge.

In reply to dculberson (Forum Supporter) :

I've written more incident reports from SRF than all other classes combined. I remember one race where I filled out 6 for SRF. 

The original Sports Renaults we re nicked named Sports Rambo. It's a great class but as with many spec classes some folks make desperate moves well beyond their talent.

Tom1200 said:

desperate moves well beyond their talent.

 

And I just found the name of my next ChampCar team!

bmw88rider (Forum Supporter) said:

In reply to dculberson (Forum Supporter) :

I've written more incident reports from SRF than all other classes combined. I remember one race where I filled out 6 for SRF. 

More than Spec Pinata? I'd think with the Miata fields they would be far worse.