At what speed will a front splitter start to work?

At what speed will a front splitter start to work?
that would depend on the splitter. :stickoutt (as well as a variety of other factors. not the least of which is the definition of the term "work".)

How much does the splitter weigh? It creates that amount of downforce at 0 mph. :)

Would one be noticable at say 50mph?

what exactly is the splitter supposed to do...i know it's functionally but what exactly is it's function..and does all splitter give the same functionality?

How much does the splitter weigh? It creates that amount of downforce at 0 mph. :)

:lol Nice Bryan!

The amount of downforce you get out of a splitter is highly dependant on how close you get it to the ground and how far it sticks out. You aren't going to be able to get any quantitative data without a wind tunnel test. If you would like to schedule some wind tunnel time let me know, I work here: swiftengineering.com

denver - Here's a solid explanation:

http://e30m3performance.com/myths/splitter/splitter.htm

denver - Here's a solid explanation:

http://e30m3performance.com/myths/splitter/splitter.htm

Excellent read. Thanks for the education!

Unless Aweather hooks you up with some wind tunnel time (i'm still waiting for my invitation lol) its going to be a black art. So start looking at similarly shaped GT cars that are manufacturer backed and had money to do windtunnel, and try to mimic best you can. Test, test, and then test some more. Only thing club racers have readily available is some track time to do some testing, since its considerably cheaper then wind tunnel, a good consistent driver, and consistent condition will allow it to be tuned. It can make a decent difference, thats why there are so many aero rules in many of the spec series...like the splitter/wing rules in WC.
Aerodynamics is very difficult to get right though...look at BMW Formula One, even the best can't always make a great design, guy got canned for that twinkeel setup haha.

You want the splitter low, and if you have a full underbody setup, its a bit different, but in general there are compromises you have to make.
1. If its too low it cna be ripped off and/or damaged easily.
2. If its too low and the car pitches to the point it touches the ground and closes of majority of airflow under it, you will run into problems as well.
3. Too high and you won't be creating much downforce and risk causing extra drag.

Just make sure you don't go getting a big splitter on and not having something in the rear to counterbalance the downforce (assuming the car is balanced before the splitter addition).

Figure right around 100 mph for any configuration that anyone who reads this forum is allowed to use.
(in terms of projection, height etc.)

faster you go, stronger it works.

Figure right around 100 mph for any configuration that anyone who reads this forum is allowed to use.
(in terms of projection, height etc.)

I'd personally put that number lower. I know I've been able to feel a definite difference in the front of our car through T1 at VIR in back to back tests with and without the splitter...T1 is definitely not a 100 mph turn. I need to pull out my track laptop to check the Stack data for actual speeds.

That said, it sounds like vjlax is asking for auto-x purposes. I would guess that any of the splitters readily available on the market would be mostly worthless in auto-x. BUT, assuming rules allow it, you could build a much larger/longer splitter that would "stall" at track speeds, but still be fine for auto-x. Take a look at AMod or FSAE cars for a general idea of what I'm talking about...their aero is designed for low speed benefits. The large angles of attack, etc. would likely lead to stall (or just WAY too much drag on the straights) at higher speeds found on track, but are a requirement for producing meaningful downforce at the speeds encountered in an auto-x.

Thanks Jay and Bryan.

Figure right around 100 mph for any configuration that anyone who reads this forum is allowed to use.
(in terms of projection, height etc.)
As an engineer with more than 10 years of wind tunnel experience, I would have predicted the same thing, but from experience on my car in back-to-back tests I can feel the splitter in the turn 4/5 combination at Sebring. I understeer without the splitter and it is very neutral with the splitter. I don’t know the exact speed of this turn, but it is probably in the 50 mph range. The splitter is 3.75 inches off the ground and sticks out 2 inches. Based on published data, a splitter like mine is probably better at reducing drag, than producing downforce. Just another opinion, but it is definitely a black art.

Bob

Unless Aweather hooks you up with some wind tunnel time (i'm still waiting for my invitation lol) its going to be a black art.

OK Steve here's your price breakdown for testing at swift:
Motons --> 4 hours
Brembos --> 4 hours
Motec ADL --> 8 hours
:)

You said the aerodynamics kick in at ~100, but I know for most F1 cars its alot higher than that. F1 race conditions are usually ideal though, and those cars weigh nothing.

doby...I'd tend to also beleive a splitter for autox is useless...just look at tunnel's car or vic's car...no wings or splitters, just fat wide tires for grip.

You said the aerodynamics kick in at ~100, but I know for most F1 cars its alot higher than that. F1 race conditions are usually ideal though, and those cars weigh nothing.

Actually, F1 aero should definitely work a speeds slower than 100. What Jay said was that the splitters we are allowed to use within most club racing rules on the front of our cars probably have little to no effect until 100 mph.

doby...I'd tend to also beleive a splitter for autox is useless...just look at tunnel's car or vic's car...no wings or splitters, just fat wide tires for grip.

Maybe they just haven't tried any aero devices...or up until now, they've gotten better gains from other mods. You assume that those cars are maxed out in build, but I'm sure there's still a lot more development that can be done. Heck, even the fastest CMod club race cars don't have optimized aero devices for the most part, are they are definitely seeing speeds where they would begin to work.

You've always gotta think outside of the box, or else you'll just end up going as fast as the fast guys instead of faster.

Unless Aweather hooks you up with some wind tunnel time (i'm still waiting for my invitation lol) its going to be a black art.

:bs

Sorry Steve. For those that want to get a solid understanding of what a splitter does, how it works, and why, as well as a good solid starting point, there was a really good article about them in Racecar Engineering a few months back. In fact, they have an excellent series going on right now on aero and they are using CFD (from the CFD company owned by BAR F1 - or is that BARF-1? ;) ).

Splitters are pretty simple. Thankfully they are also pretty simple to make effective. Yes, wind tunnel work would help you get the best balance and airdam height, but it's one of those things that is spending a lot of money chasing small gains. There is a pretty large sweet spot to getting a splitter to work effectively, especially compared with wings and other aero devices.

Also, one interesting tidbit from the Racecar Engineering series is that contrary to what I've always read, yes you can go too low.

So, back to where I started, this is not a black art at all. A little sheet of plastic with some slotted holes, some fasteners, and a little track time should give excellent results. Oh, and there is very little to no drag penalty with a splitter as well (talking about a real splitter here, not the BS riceboy crap that is called a splitter).

Figure right around 100 mph for any configuration that anyone who reads this forum is allowed to use.
(in terms of projection, height etc.)

It's WAY below this. Shoot, even cheap wings are effective well below this. I read an article or column recently (in Racecar Engineering IIRC) about a team that threw a splitter and a F3 wing element on a saloon car and it make HUGE improvements in lap times and one thing that suprised them IIRC is the big improvements in relatively slow corners.

I'd personally put that number lower. I know I've been able to feel a definite difference in the front of our car through T1 at VIR in back to back tests with and without the splitter...T1 is definitely not a 100 mph turn. I need to pull out my track laptop to check the Stack data for actual speeds.

Bryan, we make a airdam/splitter for our ITS Sentra SE-R and even in modest speed corners it made a huge improvement. The car rotated better than it ever had and that was without tinkering with it. Even other SE-R racers were commenting on how well it was getting around corners. This was at Little Talledaga (sp?) for those who know the track, through the little technical bits at the left side of the course (looking from the Paddock). Normally those type corners are a b*tch with that FWD car, but not with the airdam/splitter in place.

You said the aerodynamics kick in at ~100, but I know for most F1 cars its alot higher than that.

Not a chance. Perhaps they become much more efficient in a non-linear fashion (makes sense), but I know the aero has an impact on an F1 car even in 50 mph corners.

That said, wings and underbody ground effects are a different animal from a splitter.

Geo, any reason you had to make 20 seperate posts lol j/k

You might want to start reading some other magazines, moreso texts, there have been quite a few articles in race car engineering that have been proven to be false info, not saying this is the case for this, but its not the bible, and its engineering, so there are always people who think they have proof of something, and people with proof proving it wrong.

Of course a splitter can be too low, and if you entirely cut off airflow you have an even bigger problem. If you have a full underbody package, splitter design is much more important.

And regarding F1, they tune it to whatever needbe. If they don't need the downforce at 50mph, then they won't have it. If there are two first gear corners on the track they'll probably compromise a bit and take the added drag on the straight for quicker hairpin cornering speeds. Its all about compromises and designing something where the compromise is leaving more benefits then penalties.

Geo, any reason you had to make 20 seperate posts lol j/k

Just replying to individual posts. Didn't have time to combine them all into one.

You might want to start reading some other magazines, moreso texts, there have been quite a few articles in race car engineering that have been proven to be false info, not saying this is the case for this, but its not the bible, and its engineering, so there are always people who think they have proof of something, and people with proof proving it wrong.

Well, there certainly is that.

My real point (and may have been lost by trying to say too much too fast) is that a splitter is actually pretty simple with almost no downside. Therefore, with minimal research and fabrication, nearly any monkey can make an effective one, and with minimal time on the track can tune it.

While a wind tunnel would be great to evaluate a splitter for those with money to burn, it really doesn't make sense. The most truly effective info to be gained would be some rough idea of ideal depth and length. But even teams with money to burn will still just test them much like the rest of us monkeys. They are so simple that in the time it takes to set up a wind tunnel test, one can have the track testing largely done. I imagine it's much the same with playing with wickerbills on wings - you know what they do, so it's just down to a matter of testing different sizes and getting a feel for the effect.

Wouldn't it be nice if all other aero devices were so simple, eh? :)

We're all a bunch of monkeys :)

And I 100% Agree, and without the testing, thats what makes it a black art, thats all I was implying. Wickerbills are simpler then Splitters though, but same idea, i concur.

I wish rear wings and rear underbody diffusers were this easy...but then I look at a F430 and Enzo underbody and just drool.

Splitter by itself is very simple, but like anything it can be oversimplified and run into some problems...and overly complex and run into bigger problems haha. Biggest issue with DIY stuff for club racers I see is people creating a dangerous situation with poor mounting, and material choices.

:lol Nice Bryan!

The amount of downforce you get out of a splitter is highly dependant on how close you get it to the ground and how far it sticks out. You aren't going to be able to get any quantitative data without a wind tunnel test. If you would like to schedule some wind tunnel time let me know, I work here: swiftengineering.com

Nice! Do you know Richard Perlman?

Nice! Do you know Richard Perlman?

Yep

small world :)

And of course you must know Chris Walrod. :)

And of course you must know Chris Walrod. :)

Yep :)

Small world indeed!

Excellent read. Thanks for the education!

Yes excellent read. I know more now than I did this morning :buttrock