2011 Mustang GT track log

[SoundGuyDave]

No aero expert here, either, but...

UHMW is VERY dense stuff, with pretty significant weight in a large sheet. If I could be so bold as to recommend, think about doing a separate splitter blade and undertray. Make the undertray out of something light, like boxed sheet aluminum, and save the material weight and expense. As long as the joint between the blade and tray is smooth, the air really doesn't car what material is used. Also, when (not if, but when) the splitter gets destroyed on a berm or in an off, it's potentially easier and cheaper to replace just the exposed blade portion. When designing your mounting system, make sure you incorporate some form of sacrificial component in the mount, and carry spares with you.

Also, if you're going to pay the "non BTM aero penalty," make sure you get your "money's worth" out of it. Splitter, wing, diffuser, cunards, spats, etc all "cost" the same as an OE option rear decklid spoiler. In for a penny, in for a pound? Unless you have a lot of tracks with loooonnnngggg straights or a lot of relatively high-speed corners, you MAY find that you will be quicker overall simply carrying less weight.

No evidence, but just food for thought.

 

[neema]

Yeah that bushing will work. The only reason I didn't use the Steeda arms is because I wasn't crazy about drilling or reaming out the spindle to accommodate the bigger BJ change in late 2009. Not to mention a bumpsteer kit would have been needed as the X11 is taller than stock.

That rear sway bar coming off is a sign Neema! Like crop circles are Chuck Norris' way of telling corn, "sometimes corn just needs to lie the fuck down", this is God's way of telling you to ditch the rear bar! I know...I'm relentless.

Edit- and put the rear RC at axle center.

I appreciate your persistence. I promise you I'll try removing the sway bar at some point.

Here's a question... would it be safe to say that most people that have 1" taller ball joints (e.g. Steeda ball joints, and I'm assuming the Howe and Proforged) can run the same amount of spacers for their bumpsteer kits? I know ride height plays a role in it too, but we should be able to put our heads together and get a really good starting point, because going through the whole process of dialing in the spacers on a bump steer tie rod ends sucks.

p.s. Chuck Norris needs to tell my axle seal to stop leaking.

Damn that sucks. Sounds like you have about as bad a time as I do with my whiteline end links coming loose. Clunk! Clunk! Guess it's time to tighten them again....

If the sway bar still comes loose with these, then I give up

 

[SoundGuyDave]

I appreciate your persistence. I promise you I'll try removing the sway bar at some point.

Ditching the rear sway will only bias you towards understeer. If you have oversteer-ish tendencies, this would be a move in the right direction, and if it "goes too far", understeer is still an inherently safe condition. Given how easy it is to pull and install the rear bar, it certainly makes sense to try as an experiment.

Here's a question... would it be safe to say that most people that have 1" taller ball joints (e.g. Steeda ball joints, and I'm assuming the Howe and Proforged) can run the same amount of spacers for their bumpsteer kits? I know ride height plays a role in it too, but we should be able to put our heads together and get a really good starting point, because going through the whole process of dialing in the spacers on a bump steer tie rod ends sucks.

Generally speaking, you'll be in a pretty close ballpark if you do. What you can do to get in the general neck of the woods is to add enough to the bumpsteer stack height to get the tie-rod parallel with the lower control arm, and go from there. Yes, doing toe again and again and again (and again) sucks, but it's one of those setup things that only has to be done ONCE and then is good. Couple of ways to do it a bit more easily:

1) measure your ride-height from fender lip to spindle centerpoint. Slap a piece of tape (blue painter's) right on the fender, put a sharpie dot on it, and use that for your measurement point. Write the distance down on the tape, then pull the springs off the struts (and disconnect one front bar endlink), and put the car up on jackstands. Now, you can very simply use a jack to move the suspension around while you take toe measurements and work on your bumpsteer curve. Best approach if you're doing it in your garage by yourself.

2) This is what I do... Put the car on an alignment rack, do the toe measurement, then use the pneumatic jack (part of the rack) to lift on the K-member to get 1" or 2" of droop. To get 1"-2" of compression, grab two or three friendly neighborhood mechanics and get them to hang on the car. Front swaybar, steering rack, sit on the bumper, etc... Figure you need twice your raw spring rate to get an inch of compression. Once you have minimal change in toe angle through that range of motion, you're set.

 

[neema]

Ditching the rear sway will only bias you towards understeer. If you have oversteer-ish tendencies, this would be a move in the right direction, and if it "goes too far", understeer is still an inherently safe condition. Given how easy it is to pull and install the rear bar, it certainly makes sense to try as an experiment.



Generally speaking, you'll be in a pretty close ballpark if you do. What you can do to get in the general neck of the woods is to add enough to the bumpsteer stack height to get the tie-rod parallel with the lower control arm, and go from there. Yes, doing toe again and again and again (and again) sucks, but it's one of those setup things that only has to be done ONCE and then is good. Couple of ways to do it a bit more easily:

1) measure your ride-height from fender lip to spindle centerpoint. Slap a piece of tape (blue painter's) right on the fender, put a sharpie dot on it, and use that for your measurement point. Write the distance down on the tape, then pull the springs off the struts (and disconnect one front bar endlink), and put the car up on jackstands. Now, you can very simply use a jack to move the suspension around while you take toe measurements and work on your bumpsteer curve. Best approach if you're doing it in your garage by yourself.

2) This is what I do... Put the car on an alignment rack, do the toe measurement, then use the pneumatic jack (part of the rack) to lift on the K-member to get 1" or 2" of droop. To get 1"-2" of compression, grab two or three friendly neighborhood mechanics and get them to hang on the car. Front swaybar, steering rack, sit on the bumper, etc... Figure you need twice your raw spring rate to get an inch of compression. Once you have minimal change in toe angle through that range of motion, you're set.

Not a bad idea. I have plenty of friends who can hang like monkeys.

No aero expert here, either, but...

UHMW is VERY dense stuff, with pretty significant weight in a large sheet. If I could be so bold as to recommend, think about doing a separate splitter blade and undertray. Make the undertray out of something light, like boxed sheet aluminum, and save the material weight and expense. As long as the joint between the blade and tray is smooth, the air really doesn't car what material is used. Also, when (not if, but when) the splitter gets destroyed on a berm or in an off, it's potentially easier and cheaper to replace just the exposed blade portion. When designing your mounting system, make sure you incorporate some form of sacrificial component in the mount, and carry spares with you.

Also, if you're going to pay the "non BTM aero penalty," make sure you get your "money's worth" out of it. Splitter, wing, diffuser, cunards, spats, etc all "cost" the same as an OE option rear decklid spoiler. In for a penny, in for a pound? Unless you have a lot of tracks with loooonnnngggg straights or a lot of relatively high-speed corners, you MAY find that you will be quicker overall simply carrying less weight.

No evidence, but just food for thought.

I thought about this, but at .25" thickness, UHMW sheet is ~1.2 lbs per square foot. The splitter mocked up in the rendering is just under 15 square feet, so at 18 pounds, it doesn't seem too bad for version 1. I thought it would be cool to keep the nose thicker at .25", while machining the thickness down on the pan that sweeps back under the engine, using triangulated ribs to keep it strong while thinning less critical areas. Upside down gurney flaps in front of the tires and spats can be added on, and side plates can help force more air over the splitter.

I'm still trying to figure out the best way to make the mounts "sacrificial," because I want the splitter to eject if it takes a digger. So far, my favorite method of mounting and bracing splitters is with aluminum angle and hood strut ends that snap onto the mounting balls. You can make little control arms that hold the splitter in various axes on the car. Here's where I got my inspiration.

I just need a James Bond eject button for it.


The wing in the back will be some sort of big honkin generic "2D" APR wing that I'll try to get into clean air. I need to double check the rules on the position of the airfoil--being farther back and higher up will get the wing over/behind the air passing over the greenhouse of the car. Still thinking of an end plate design as well as an adjustment mechanism.

Thanks for the pointers, Dave

 

[Pentalab]

"What I'd like to use is repro UHMW, or reprocessed ultra high molecular weight polyethylene. The virgin material is what you see in households used for cutting boards, but the reprocessed stuff is essentially recycled and reformed material originally used for chain guides, wear plates, etc. Some benefits compared to virgin UHMW is that it's black and it's cheaper."

I used the virgin white UHMW for another outdoor application..and after a few years, it turned brittle, and pieces were breaking off the edges. This was 1/8" thick material. I think it was caused by UV (sunlight). It may have also been from freeze -thaw cycles........ or a combo of both.

You may fare better with the recycled black UHMW.

Lexan is another material that might work... but it would be cost prohibitive..and difficult to work with.

On another note. Do you still have the OEM differential + 2 piece drive shaft ?
An eaton tru-trac / torsen + a DSS-DS would be a winner.

 

[Norm Peterson]

That rear sway bar coming off . . .

I'm pretty sure that's a front bar in neema's picture.

Offhand, the only reason I can think of for why it's pulling out the bolt is if the bushing and its strap are mis-matched (IOW, you're having to close up a gap between the strap and the chassis bracket.


Norm

 

[sheizasosay]

I'm pretty sure that's a front bar in neema's picture.

Offhand, the only reason I can think of for why it's pulling out the bolt is if the bushing and its strap are mis-matched (IOW, you're having to close up a gap between the strap and the chassis bracket.


Norm

Damn....apparently I'm wanting him to take that rear sway bar off so bad my mind produced it's own "rear" swaybar in Neema's typing. And out of all his pics, somehow I missed the one pic showing the front bar bracket identifying it. Benadryl is a helluva drug!

Neema- God doesn't require you to remove your rear bar at this time.

 

[Roadracer350]

Why not just use Durabond? It's a composit material sandwiched between two .012" thick alum sheets. Super strong and cheap. I picked mine up for about 100 from my local fastsighns and that was delivered.

 

[ArizonaGT]

If the sway bar still comes loose with these, then I give up

http://www.steeda.com/store/images/products/555-8113.jpg[/IG][/QUOTE]

I use those SB mounts as well, so far they have been rock solid. I broke one of the factory mounts :-/

 

[modernbeat]

...I thought about this, but at .25" thickness, UHMW sheet is ~1.2 lbs per square foot. The splitter mocked up in the rendering is just under 15 square feet, so at 18 pounds, it doesn't seem too bad for version 1. I thought it would be cool to keep the nose thicker at .25", while machining the thickness down on the pan that sweeps back under the engine, using triangulated ribs to keep it strong while thinning less critical areas. Upside down gurney flaps in front of the tires and spats can be added on, and side plates can help force more air over the splitter...

At that thickness the air pressure forces will deform your material unless you add a huge amount of support rails to it. And even then it will still pucker and not present a flat, smooth surface.

If you want to go that thin I'd use aluminum and go just a tad thinner.

 

[sheizasosay]

At that thickness the air pressure forces will deform your material unless you add a huge amount of support rails to it. And even then it will still pucker and not present a flat, smooth surface.

If you want to go that thin I'd use aluminum and go just a tad thinner.

Why is polycarbonate not considered for the splitter? At least a 6" shelf or the protruding portion? Not a good material?

 

[modernbeat]

If you just want an air dam, it's OK. But if you want a real splitter that continues under the car, it will have REAL forces acting on it. If you can bend the material by hand, it will bend under the car and you lose the aero effect you are trying to capture. Even just puckering by not having the holes lined up as it gets cold and hot will cause it to warp. And heat from the exhaust will also make it move around.

You also want something that will stand up to abuse. Poly is good for that, but the reason it's good is because it bends, which negates the aero you want. Lots of autocrossers will recommend Coroplast or other ultra lightweight sign material, which will not only bend, but will pull apart at track speeds with real downforce.

These days I tend to make splitters out of 1/8" or or 3/32" aluminum or 3/8"-5/8" cabinet plywood (more thin plys). Yes, they are not the lightest or most exotic, but they are easy to work with, inexpensive enough to have spares made, and will take a huge amount of abuse, which they all end up seeing.

Here's a 3/4" thick plywood splitter on the Subaru we prepped for the Pikes Peak Hill Climb. Brianne Corn, the driver in the photo, does a lot of ditch hooking and would be surfing on the splitter through gunnite lined ditches in a number of spots at Pikes Peak.

Another one we built for track abuse, this 3/16" thick splitter has held up well. The car was drug down the track on it, coaster over curbs, dug into grass, and more. It's worked very well, but it's replacement will be a little thinner to save a few pounds.

Here is the final product for the Mustang. It supports more than 400 lbs of downforce and goes almost to the middle of the front tires.

 

[neema]

If you just want an air dam, it's OK. But if you want a real splitter that continues under the car, it will have REAL forces acting on it. If you can bend the material by hand, it will bend under the car and you lose the aero effect you are trying to capture. Even just puckering by not having the holes lined up as it gets cold and hot will cause it to warp. And heat from the exhaust will also make it move around.

You also want something that will stand up to abuse. Poly is good for that, but the reason it's good is because it bends, which negates the aero you want. Lots of autocrossers will recommend Coroplast or other ultra lightweight sign material, which will not only bend, but will pull apart at track speeds with real downforce.

These days I tend to make splitters out of 1/8" or or 3/32" aluminum or 3/8"-5/8" cabinet plywood (more thin plys). Yes, they are not the lightest or most exotic, but they are easy to work with, inexpensive enough to have spares made, and will take a huge amount of abuse, which they all end up seeing.

Here's a 3/4" thick plywood splitter on the Subaru we prepped for the Pikes Peak Hill Climb. Brianne Corn, the driver in the photo, does a lot of ditch hooking and would be surfing on the splitter through gunnite lined ditches in a number of spots at Pikes Peak.

Another one we built for track abuse, this 3/16" thick splitter has held up well. The car was drug down the track on it, coaster over curbs, dug into grass, and more. It's worked very well, but it's replacement will be a little thinner to save a few pounds.

Here is the final product for the Mustang. It supports more than 400 lbs of downforce and goes almost to the middle of the front tires.

UHMW may flex, but with aluminum angle or box tubing (used for mounting points) there should be some rigidity under the engine. It's self-lubricating, which should help it slide over rumble strips and anything else 3" off the ground. If there is too much flex coming from the splitter portion that sticks out, then two support struts may not do the trick. It may need four. Oh, it floats too, so that may help on wet days




An unrelated note, here's what fitment of a 305/35/18 NT01 on an 18x12 looks like. The 305 looks a little too wide on 10.5 width wheels. See the comparison between the two below.

Also, I measured the inner barrel diameter using a Stoptech mock-up tool for the ST60 caliper on a 380mm rotor and it will not clear the barrel of the wheel. The wheel below wasn't made for a mustang, but I figured an 11" width wheel would have similar dimensions.

Just FYI.

 

[modernbeat]

UHMW may flex, but with aluminum angle or box tubing (used for mounting points) there should be some rigidity under the engine. It's self-lubricating, which should help it slide over rumble strips and anything else 3" off the ground. If there is too much flex coming from the splitter portion that sticks out, then two support struts may not do the trick. It may need four. Oh, it floats too, so that may help on wet days ...

My recommendations for those materials is not based on numbers in a catalog, computations or supposition. It's based on failures and successes during competition. I no longer use plastic for any ground plane areo with real force. I'll be glad to use it for cosmetic parts, like the Laguna Seca splitter, which the properties of plastic excel at. Our aluminum splitter looks like crap after a few months of track use. The LS plastic splitter looked great after more than a year of use.

 

[kcbrown]

My recommendations for those materials is not based on numbers in a catalog, computations or supposition. It's based on failures and successes during competition. I no longer use plastic for any ground plane areo with real force. I'll be glad to use it for cosmetic parts, like the Laguna Seca splitter, which the properties of plastic excel at. Our aluminum splitter looks like crap after a few months of track use. The LS plastic splitter looked great after more than a year of use.

Why not a plastic splitter with an aluminum core? Seems like it might be the best of both worlds, though it might be difficult to make. It probably wouldn't make sense for you guys at Vorshlag, since you regularly do your own fabrication, but it might make more sense for someone who wants such a splitter and wants it to last.

 

[Roadracer350]

Jason, what about .500" Durabond

 

[modernbeat]

Why not a plastic splitter with an aluminum core?...

What do you gain with that? Save a couple pounds for a huge fabrication hassle laminating materials? If you want some abrasion protection below the splitter then just use some blocks of Teflon, jabroc or titanium (if you like sparks).

Jason, what about .500" Durabond

I assume this is the opposite of what KCBrown suggested, a thin aluminum sheet laminated onto a foam or plastic corrugated core material. I've found they typically don't have enough strength to use at higher speeds and will deform unless you use a ridiculous amount of support structure, and will often pull through and drag under the car. I've looked at Coroplast, Gatorfoam, alumalite and others. They are all too soft and fragile. While they don't warp in a waffle pattern like the plastics, they still droop and bow with any pressure. I have had friends successfully use alumalite for aero aids at autocross, Texas Mile and Pikes Peak, but aside from autocross, where light weight rules all, it was risky to use it. It still deformed and wore way too much to use for multiple events.

Here's a pic of a Laguna Seca splitter. The front supports pulled through the plastic splitter and allowed it to droop, then it pulled through the other fasteners that held it to the bumper cover until it drug the track surface. Luckily it did not roll under the car, but the owner slowed down and came in off the track as soon as it happened. It only ground about three inches off the front of the splitter.

 

[Roadracer350]

Durabond is a solid composite material sandwiched between 2 thin sheets of aluminum. The alum is .012" so total alum thickness is .024" with a total composit thickness of .476". It's hard as crap to cut! What did you use for the splitter on the red car?

 

[modernbeat]

We used 3/16" aluminum on the red Mustang GT. That Subaru STi at Pikes Peak used 3/4" cabinet plywood with something like 12 layers of wood in it. Since then we use 1/8" aluminum for lighter duty aero.

 

[neema]

Small update. The Moroso 20572 aluminum oil pan showed up. I posted this in a few forums just for reference. It's tough to find pictures of the pan with the sump lid removed. I weighed it on my cheap bathroom scale and it came in at 9.5 lbs, but I'll give it a weigh on a proper shipping scale before I install it.

Prices have gone up, but it's still sub $500 if you hunt around. The steel version is a steal (no pun) at $300 shipped. After inspection, I don't know how I could ask for more from an oil pan (cough cough 302S pan cough). The welds are immaculate and it arrived perfectly clean (no debris/dust to get into the oil). This will definitely encourage me to change my oil more frequently, since there's no way to enjoy the way it looks once installed.


I removed the sump cover to expose the trap doors and baffles in some pictures.

The pan comes with the oil level sensor bung installed in the correct location

Optional oil drainback from a turbo/supercharger seen on the left

This will stay plugged for me

The sump cover only lets oil through on the perimeter

Optional fitting for oil temperature sensor on the bottom of the pan

Magnetic drain plug shown on bottom left. This view shows the asymmetric shape of the pan. It flares out toward the bottom sump pickup to increase oil capacity

There are three separate compartments, each with trap doors to the sump pickup. Each door is clocked differently to open or close in specific scenarios (i.e. cornering loads, accelerating)

A view of the passenger side compartment