77 replies to this topic

[andygo]

I have a 3 year old ff1600 car that my son races with a little success. However he always feels it is short on power and to this end we have run several engines in it over the last 3 years. They have all come off the dyno showing good BHP, but lack punch. Got lots of onboard showing him making up ground going into corners and initial exit but unable to capitalise on it, even when the car in front is clearly very sideways.

Happy with gearing etc, always on very good tyres and brakes, corner weighted and measured after every run.

Scratching our heads now as to what else we can do to find that last little bit of performance. Wonder if it can be anything to do with rake?

Edited by andygo, 21 September 2011 - 11:36.

[cheapracer]

Happy to have a go at it until Fat Boy comes along but might be an idea to have a gander at the onboards first and see if anything obvious ...

[Paolo]

Too much toe in and low tyre pressures can increase rolling resistance.
Also, engine on dyno is one thing and engine on the car is another. How well is that engine breathing?
Finally: could it be you have friction losses in the drivetrain or brakes sticking (or even driver operating them inadvertently)?

Edited by Paolo, 21 September 2011 - 15:20.

[sblick]

If you are running in America, if you haven't already buy an Ivey engine. Toe in is a definite no no on FF at least from what I have seen on ours. We have had problems with timing on distributor slipping causing power loss. Bad valve adjustment can lead to power loss also We generally run 11.5-15 psi in the tires. I am of the "make sure it is breathing right" crowd to. Dusty tracks clog the filter very quickly. Wrong headers can be a drag

[mariner]

If you have not already done so and have any kind of data logging, or even an accurate time counter on your video, try some straight line acceleration and coast down tests on a track or road. Go both ways to get rid of slope/wind as much as possible.

With the camera time lapse data and a view in camera of the tacho. you should be able to sense check the wheel horsepower and also any parasitic drag.

[andygo]

We run zero toe in. We can't see much on the PI data logging - all seems very consistent. Brakes are not dragging. Car is breathing fine - new K&N filters on both our identical engines. Driver not dragging brakes. New CV joints (Old ones were fine), gearbox maybe due a service now, but never any swarf from dog rings - original dog rings look like brand new. Box seems pretty free when turning by hand, we use trick American thin oil that looks pristine whenever its drained. All looks fine on the onboard as well. Its just missing that little bit of killer woof.

Cars not THAT bad, its held the lap record at Oulton Park for 4 years, but its places like Silverstone which shows up a lack of straightline speed. Its generally a very quick car after all, but trying to get the last bit is always the hardest part...

Edited by andygo, 21 September 2011 - 17:00.

[Tony Matthews]

Your son isn't seven feet tall is he?

[Fat Boy]

Happy to have a go at it until Fat Boy comes along but might be an idea to have a gander at the onboards first and see if anything obvious ...

Cool...notoriety.

Toe settings: I've never once seen a toe setting affect straight line speed in anything. Logically, you would say it has to, but I've never been able to see it in data, and at times I've ran some fairly hefty toe settings. I know the FFord and Spec racer crowd obsesses about running a zero setting, but I would argue that it's more an issue of paddock group think than actual data. Run whatever makes the car go the fastest around the track. If that happens to be zero, then fine. If that happens to be a few mm in or out, then fine. Same goes for camber.

Run everything your engine builder recommends. Don't run an engine from 'X' builder with the exhaust from 'Y' just because you happen to have that exhaust sitting around. Run every damned thing he tells you to run and have him come to the track with you to tune it, even if just for a day. Be your engine builder's best customer. If you don't trust him to spec out all your parts or tune your engine, then look for a different builder.

Top speed is overwhelmingly influenced by aero drag. Are you running the same car as your competition? If you're running a car with a different body, then that may be it right there. Regardless if the body 'looks' slick or not, it may be a parachute. On the flip side, if you can't even stay in a draft, then you can discount the effect of the bodywork, because a draft will make a bigger difference to drag than a body ever could.

Is the car at minimum weight? It matters. When you finish qualifying, you should be as close to minimum as you possibly can be. At my last race we rolled across the scales after qual. They were plugging in the numbers for the driver and car weight into a computer. As one official called out the numbers the other said, "Jesus!...you're only over by 1 pound." The other one says, "Ya, those guys don't F around." If you're carrying around an extra 25 pounds on the car and an extra 5 gallons of fuel, it is a measureable acceleration difference.

"I'm way faster into the corner, but they're killing me on the way out." Then don't be faster than your competition in places that don't count. It's a FFord. They respond well to rolling speed and early full throttle. Notice I didn't say cracking the throttle early. Many times a guy will crack the throttle early, but take forever to get to full throttle. A FFord does not have wheelspin issues. You should be able to apply throttle in an almost digital manner. Where you reach full throttle is the important variable, not where you initiate it. To make a pass, you must be better on corner exit. Sacrifice the entry speed, but get the car turned early and make damned sure that you get to full throttle first and are catching the car ahead of you as you unwind the steering wheel and reach track out.

Now to your real question, rake. The simple fact is, I don't know. I know that rake is really powerful balance tuning tool on those cars, but as to it's effect on drag, I really have no way of saying. I would guess that within the range that most people run, it's probably a pretty small variable. It's not going to influence downforce or frontal area too significantly, so it's probably not going to influence drag, but that's not based off of any hard data, just instinct.

Hope this helps.

[Fat Boy]

A couple more things after watching the videos.

He needs to draft better. He's pulling out of the draft early in most cases. You have to suck up on the car in front and pop at the last instant after you've built up a speed advantage.

He needs better footwork with the throttle. There's way too much off-on.

He needs to be wearing a HANS.

[cheapracer]

Just an opinion;

The car has no initial turn in bite and your boy is braking late to weight the fronts and chopping at the wheel to get some feedback at turn in - that, besides the tyre drag he's offering, always ends up as mid to late corner oversteer which is ruining your exit speed which may be giving the illusion of your "lack of power". The late braking and early corner speed/work is also giving you the illusion your corner speed is good, it's not.

Don't get wrapped up in the theoretical perfect setup too much, experiment. You need to get that car to turn in. I would start dialing in a little toe out and of course playing with tyre pressures. Soften front bump damping or increase rebound on the rear. Soften front roll bar/stiffen rear.

Don't be afraid to change rear toe either although that's more depending on the track, fast tracks maybe a little toe in for stability and tight a little toe out for extra rotation mid corner.

Rake is next, dropping the front or raising the rear will give you a bit more weight on the fronts in roll as the roll axis tips forward.


Cornering 101 - Tell your lad to brake a little earlier and get on it a little earlier while settling down his inputs, trust the car but of course he needs a car to trust. You need to change his driving style and bring the car to that style, not vise versa and that will require discipline. While he's willing to adapt to a bad car ultimately you're not going to move forward - watch this video for the result you want to aim for .. .. damn that guy could be drinking a cup of tea while he's racing for first place while your son looks like he's wrestling a gorilla.

After saying all that I should ask that you are aware of the current condition of your dampers and they have been recently checked over?

Edited by cheapracer, 22 September 2011 - 08:56.

[andygo]

Just an opinion;

The car has no initial turn in bite and your boy is braking late to weight the fronts and chopping at the wheel to get some feedback at turn in - that, besides the tyre drag he's offering, always ends up as mid to late corner oversteer which is ruining your exit speed which may be giving the illusion of your "lack of power". The late braking and early corner speed/work is also giving you the illusion your corner speed is good, it's not.

Don't get wrapped up in the theoretical perfect setup too much, experiment. You need to get that car to turn in. I would start dialing in a little toe out and of course playing with tyre pressures. Soften front bump damping or increase rebound on the rear. Soften front roll bar/stiffen rear.

Don't be afraid to change rear toe either although that's more depending on the track, fast tracks maybe a little toe in for stability and tight a little toe out for extra rotation mid corner.

Rake is next, dropping the front or raising the rear will give you a bit more weight on the fronts in roll as the roll axis tips forward.


Cornering 101 - Tell your lad to brake a little earlier and get on it a little earlier while settling down his inputs, trust the car but of course he needs a car to trust. You need to change his driving style and bring the car to that style, not vise versa and that will require discipline. While he's willing to adapt to a bad car ultimately you're not going to move forward - watch this video for the result you want to aim for .. .. damn that guy could be drinking a cup of tea while he's racing for first place while your son looks like he's wrestling a gorilla.

After saying all that I should ask that you are aware of the current condition of your dampers and they have been recently checked over?

Maybe not the best video I put up as he was on brand new unscrubbed tyres which take a lap or so to get rid of the release agent. He did win the championship with that overtake though.

Whilst I appreciate the video you suggest, he's not at the front though, my mum could drive that smoothly within the cars comfort zone..

[Fat Boy]

The two clips I watched both seemed to be in damp conditions. I'd expect to see the car moving around quite a bit if the track were a bit wet.

In general, when you're dealing with a light car with no downforce and street type tires, it's going to move around a bit. If it's not, you're just not going fast enough. Having said that, I'm a big believer in getting stability on corner entry, regardless of the car. It lets the driver be more aggressive with his inputs and attack a track as opposed to continually balancing the car.

Are you running with a pro team or are you trying to have a go at it on your own?

[cheapracer]

Maybe not the best video I put up as he was on brand new unscrubbed tyres which take a lap or so to get rid of the release agent.

I did watch plenty of laps, plenty of clips of him on the net that I watched before I posted my opinion.

He did win the championship with that overtake though.

He won "a" championship ....

Whilst I appreciate the video you suggest, he's not at the front though,

.. and so did he.


...and so have I.

my mum could drive that smoothly within the cars comfort zone..

That guy's driving style is excellent. Maybe there's some history here where your son has proven to be faster than him, so what, there's many other reasons for that, car, balls, money etc. but doesn't change that is how all the very elite and successful drivers drive bar a very rare handful. Of course that necessarily comes back to having a chassis setup under you that can be driven accordingly.

Edited by cheapracer, 23 September 2011 - 05:12.

[MatsNorway]

I'm a big believer in getting stability on corner entry, regardless of the car.

Nice driving Andygo

Is it a 2 way diff?

could it be made tighter during braking?

Just asking.

[JJW]

not a lot of appreciation for the very good advice you're getting here - what's the point of asking for opinions if you just reject them to confirm your existing thinking (which seems to be, we're not doing anything wrong, its the engine builder's fault)

[andygo]

not a lot of appreciation for the very good advice you're getting here - what's the point of asking for opinions if you just reject them to confirm your existing thinking (which seems to be, we're not doing anything wrong, its the engine builder's fault)

Not sure how you arrive at that position - cant see any reference to poor engine performance or rejection of other peoples advice. Thanks however for your input - it was most helpful.

[Johan Lekas]

Not sure how you arrive at that position - cant see any reference to poor engine performance or rejection of other peoples advice. Thanks however for your input - it was most helpful.

You have climbed high on the "Feedback Steps"

[cheapracer]

Is it a 2 way diff?

Yup, works in both forward and reverse gears.

FF are all open differential, LSD is illegal.

[cheapracer]

not a lot of appreciation for the very good advice you're getting here - what's the point of asking for opinions if you just reject them to confirm your existing thinking (which seems to be, we're not doing anything wrong, its the engine builder's fault)

Meh it's cool, it's just an opinion that's being discussed in an open public forum and regardless of if the topic source is present (a poster) or came from elsewhere (mostly) - the info is posted for all to read and available to be further discussed/rebuked/contested or ignored, it's all just a bit of fun.

Also process of elimination is very much a valid way to reach a goal too.

[JJW]

Not sure how you arrive at that position - cant see any reference to poor engine performance or rejection of other peoples advice. Thanks however for your input - it was most helpful.

you're welcome

[Kelpiecross]

I have a 3 year old ff1600 car that my son races with a little success. However he always feels it is short on power and to this end we have run several engines in it over the last 3 years. They have all come off the dyno showing good BHP, but lack punch. Got lots of onboard showing him making up ground going into corners and initial exit but unable to capitalise on it, even when the car in front is clearly very sideways.

Happy with gearing etc, always on very good tyres and brakes, corner weighted and measured after every run.

Scratching our heads now as to what else we can do to find that last little bit of performance. Wonder if it can be anything to do with rake?

Why somebody is faster than somebody else is one of those mysteries with no (or few) answers.

On Top Gear's celebrity laps in the Reasonably Priced Car, the fastest non-racing driver is about one minute 46 seconds - Vettel was 1min - 44sec - two full seconds faster. Why is he so much faster? You would think that most of the lap was just foot-to-the-floor with little opportunity to be faster than somebody else. Not bravery in such a low powered car or experience in various exotic racing cars - he is just faster.
If you knew why someone was fast and could teach it to others you could probably make a lot of money.

[Ross Stonefeld]

Got lots of onboard showing him making up ground going into corners and initial exit but unable to capitalise on it...

I've read this thread a few times but this particular morning this comment made me smile. Are we sure the problem isn't more fundamental? That old chestnut, I'm catching him in the corners but he's killing me on the straights?

Not to be completely flippant though. Are you sure there's a power/speed deficit or is it a visual deduction?

[andygo]

I've read this thread a few times but this particular morning this comment made me smile. Are we sure the problem isn't more fundamental? That old chestnut, I'm catching him in the corners but he's killing me on the straights?

Not to be completely flippant though. Are you sure there's a power/speed deficit or is it a visual deduction?

Not sure what the issue is. I have always said that whatever the engine we have, would Schumacher be able to get more out of the car? If so, drive faster son.

I have onboard footage showing the car in front very sideways on the exit of corners yet still manages to pull away even though our car has gained on the immediate exit.

[PvL]

I've read this thread a few times but this particular morning this comment made me smile. Are we sure the problem isn't more fundamental? That old chestnut, I'm catching him in the corners but he's killing me on the straights?

Not to be completely flippant though. Are you sure there's a power/speed deficit or is it a visual deduction?

Reminds me of a driver who didn't understand the basic "distance=speed*time"... "I close the gap under braking, but out of the corner he is pulling away!" Looks can be deceiving

[Fat Boy]

You have climbed high on the "Feedback Steps"

Hey Mr. 18 posts. Adults are speaking. You should be quiet for now.

[Fat Boy]

Not sure what the issue is. I have always said that whatever the engine we have, would Schumacher be able to get more out of the car? If so, drive faster son.

I have onboard footage showing the car in front very sideways on the exit of corners yet still manages to pull away even though our car has gained on the immediate exit.

I've asked some questions that need answering. I'm curious what these answers are.

Schumacher (or whomever you see as the best driver) would go faster, but perhaps not for the reasons you think. First, an experienced driver knows where the time is. He also knows what a really good car is supposed to feel like. Your son, through no fault of his own, lacks on both accounts. I promise you that every guy out there is driving as 'hard' as he know how to drive. No one goes out just to F-about. Driving hard is not really the issue. It's driving better. When you put on stickers for qualifying, you don't get speed by grabbing the car by the scruff of the neck and shoving it around the track. You get speed by doing everything you're already doing just a bit better. Your braking efficiency needs to improve a couple of percent. You need to get off the brake just a tick earlier. You roll just a couple mph more into the corner with slightly smoother inputs than before. You hit your apex just a bit tidier and more precise than you have been and you go to throttle a few feet earlier. It's not any one thing that you have to do better when driving faster, it's everything. While there are corners where balls come into play, generally speaking, they don't. If you're driving around the track constantly scaring yourself, then you need to find a different way to spend your time. 'Ballsy driver' is just another way of saying, "A guy that crashes a lot".

I haven't seen the footage you're speaking about, but if I can venture to guess what happened on the sideways car that pulls away. First, perhaps he wasn't as sideways as you thought. A racecar on road tires can move around quite a bit without slowing it down excessively. Second, perhaps your son was sliding in a similar manner. Third, did he hit the rev-limiter or short shift just prior to the competition pulling away? Shifting at the correct RPM is a much under-appreciated skill. Again, I'll ask if he was drafting correctly, because in the vids that I saw, he often wasn't. There's really no way to know what your issue is, but these are all questions that need to be answered to figure it out.

[Ross Stonefeld]

Just for added info, here's another lap of the same circuit (Oulton Park) in a treaded tire Ford 1600. This time driven by a guy who's usually racing Japanese F3.

http://www.youtube.c...feature=related

[andygo]

I think my son is reasonably experienced. www.goughracing.co.uk. It's not particularly up to date.. The green ff1600 he is following in vid 2 is an identical car run by Don Hardman.

[cheapracer]

I think my son is reasonably experienced.

I'm sure he is, I'm sure he's very fast at local level, if not the fastest and on occasion elsewhere - I'm sure your proud of his results too but have you ever wondered why he's not quite making that final step? I'm sure you are, that's why you're here.

I haven't seen the footage you're speaking about,

Same elsewhere - won't turn in, lift off snap oversteer, slow out - feel sorry for him sawing away at the wheel and throttle compensating. You see here on the slippery cement dust the cars a right bloody handful. Missing some draft opportunities too.

Edited by cheapracer, 23 September 2011 - 18:32.

[cheapracer]

Just for added info, here's another lap of the same circuit (Oulton Park) in a treaded tire Ford 1600. This time driven by a guy who's usually racing Japanese F3.

http://www.youtube.c...feature=related

Yeah nice, not easy to find the pointy end FF guy's onboard vids, I thought they would have been a dime a dozen on the net.

Anyways, this is a Former Dutch Junior Rotax Kart Champion and now doing very well with wins and podiums in the Dutch premier FF championship - Duratec engine and slicks but not too far removed from FF1600 ...

[MatsNorway]

FF are all open differential, LSD is illegal.

ok.

But we could still tune it?

In RC cars there is standard type geardiffs that gets tuned with simply the oil. So it should be possible with a bigger diff too. Not likely a option here im just saying.

Edited by MatsNorway, 23 September 2011 - 20:26.

[Fat Boy]

ok.

But we could still tune it?

Not legally

[carlt]

Got lots of onboard showing him making up ground going into corners and initial exit but unable to capitalise on it,

I also think he is rushing his moves , quick into the corner - up the arse of the car in front - got to get off the throttle or dab the brakes to avoid contact
The car in front is then on the throttle earlier for corner exit .

This is why there is so much on /off the throttle ,its not just balancing the car

Its all about the timing of the moves - microseconds more patience !

[Fat Boy]

I'm sure he is, I'm sure he's very fast at local level, if not the fastest and on occasion elsewhere - I'm sure your proud of his results too but have you ever wondered why he's not quite making that final step? I'm sure you are, that's why you're here.

This, or Pops is here to brag on his boy, which why none of the questions I've asked have been answered.

Same elsewhere - won't turn in, lift off snap oversteer, slow out - feel sorry for him sawing away at the wheel and throttle compensating. You see here on the slippery cement dust the cars a right bloody handful. Missing some draft opportunities too.

Thanks for posting the links. Ugh. That thing's awful. I think the entry problem is that the car is way too loose, and the driver is worried about the rear on turn-in. Regardless, it's bad right from the entry of the corner. In the second clip, he's got too much rear brake to boot. This goes back to what I said about an experienced driver. Schumacher wouldn't try to go faster than the driver of this car. After the first couple laps, he'd pit and make changes to the balance instead of trying to hustle around a really bad handling racecar.

This seems to be the case of 'tune your chassis and find 100 HP'.

[Ross Stonefeld]

To follow cheap's link of the Dutch Formula Ford 1800 w/slicks, same driver but at Spa. But over driving in my estimation. But it could be late in the race or end of a test run or whatever.



Either way, leeeeeetle too abrasive with the inputs.

[Fat Boy]

Ahhh, yes, the old 'apex optional' line.

[MatsNorway]

Not legally

What you mean?

Is there a spec grease on the diffs?

[cheapracer]

Not legally

[mariner]

From Ross Stonefield

"Just for added info, here's another lap of the same circuit (Oulton Park) in a treaded tire Ford 1600. This time driven by a guy who's usually racing Japanese F3.

[url="http://www.youtube.com/watch?v=Ed3p_Dkialo...feature=related""]http://www.youtube.c...lo...e=related"[/url]

Slightly off topic but I couldn't help posting this other "on board" around Oulton Park from long ago



Funnily enough the tyre grip levels are possibly very close and both cars have a lot of suspension movement by modern standards.

[Tony Matthews]

Yep, that's the way to do it!

[saudoso]

This might be silly, but here it goes anyway:

http://www.rfactorce.....sition Plugin
http://www.racecar-e...the-real-world/

Some time to do data logging and experimenting could help, so this could do it by the price of a Logitech Wheel and some patience. May be even try to purchase Martin's model.

[Magoo]

Cool...notoriety.

Toe settings: I've never once seen a toe setting affect straight line speed in anything. Logically, you would say it has to, but I've never been able to see it in data, and at times I've ran some fairly hefty toe settings. I know the FFord and Spec racer crowd obsesses about running a zero setting, but I would argue that it's more an issue of paddock group think than actual data. Run whatever makes the car go the fastest around the track. If that happens to be zero, then fine. If that happens to be a few mm in or out, then fine. Same goes for camber.

Run everything your engine builder recommends. Don't run an engine from 'X' builder with the exhaust from 'Y' just because you happen to have that exhaust sitting around. Run every damned thing he tells you to run and have him come to the track with you to tune it, even if just for a day. Be your engine builder's best customer. If you don't trust him to spec out all your parts or tune your engine, then look for a different builder.

Top speed is overwhelmingly influenced by aero drag. Are you running the same car as your competition? If you're running a car with a different body, then that may be it right there. Regardless if the body 'looks' slick or not, it may be a parachute. On the flip side, if you can't even stay in a draft, then you can discount the effect of the bodywork, because a draft will make a bigger difference to drag than a body ever could.

Is the car at minimum weight? It matters. When you finish qualifying, you should be as close to minimum as you possibly can be. At my last race we rolled across the scales after qual. They were plugging in the numbers for the driver and car weight into a computer. As one official called out the numbers the other said, "Jesus!...you're only over by 1 pound." The other one says, "Ya, those guys don't F around." If you're carrying around an extra 25 pounds on the car and an extra 5 gallons of fuel, it is a measureable acceleration difference.

"I'm way faster into the corner, but they're killing me on the way out." Then don't be faster than your competition in places that don't count. It's a FFord. They respond well to rolling speed and early full throttle. Notice I didn't say cracking the throttle early. Many times a guy will crack the throttle early, but take forever to get to full throttle. A FFord does not have wheelspin issues. You should be able to apply throttle in an almost digital manner. Where you reach full throttle is the important variable, not where you initiate it. To make a pass, you must be better on corner exit. Sacrifice the entry speed, but get the car turned early and make damned sure that you get to full throttle first and are catching the car ahead of you as you unwind the steering wheel and reach track out.

Now to your real question, rake. The simple fact is, I don't know. I know that rake is really powerful balance tuning tool on those cars, but as to it's effect on drag, I really have no way of saying. I would guess that within the range that most people run, it's probably a pretty small variable. It's not going to influence downforce or frontal area too significantly, so it's probably not going to influence drag, but that's not based off of any hard data, just instinct.

Hope this helps.

+1. A prose poem on small-bore formula car racing.

[Bloggsworth]

I doubt small variations in rake would have a significant aerodynamic effect on an FF car, they would have more effect on the handling unless, of course, you are planning to move the suspension mounting points in equal increments to the raising or lowering of whichever end of the car you plan to move.

One thing you can always try is to make a radical alteration to skew the handling then have the driver bring it back to what he feels is best - Sometimes it's just a case of familiarity obscuring intent...

[Fat Boy]

Thanks, Mags

[gruntguru]

That thing's awful. I think the entry problem is that the car is way too loose, and the driver is worried about the rear on turn-in. Regardless, it's bad right from the entry of the corner.

Probably just another case of "driver likes the feel of a particular setup, but he would actually be faster with something not quite as loose"

[gruntguru]

After looking at several of the videos of your car, I didn't see a single car that had a power advantage over yours. In most cases, I thought your engine was better.

[Fat Boy]

Probably just another case of "driver likes the feel of a particular setup, but he would actually be faster with something not quite as loose"

Kind of another way of saying, "Not experienced enough to know what a really fast car is supposed to feel like." Often drivers think that if they aren't working their ass off, then they can't go fast. The truth is that a when a car is tuned correctly the driver should not be working all that hard in a physical sense. His inputs should be more subtle instead of gross, opposite lock catches and big steering additions due to push. That round thing in front of you can act just like a brake pedal.

[JJW]

As somebody very old and wise once said to me when I was tuning the balance in my clubman 'a little bit loose feels fast but a little bit tight is generally faster'. The latter is also less likely to have you backed into a barrier think WTF just happened!

[gruntguru]

I think drivers like that little extra responsiveness you get when the setup is a little bit loose. The fact that they like it doesn't mean it has to be faster.

[Johan Lekas]

From "Aerobytes" section of Racecar Engineering July 2008
MIRA windtunnel testing of Spectrum FF