ZX-Tex

iTrader: (15)

Is an LS1 enough?

OK this is all pretty cool because some of it is analogous to bike racing. Trail braking on a bike helps with turn-in because it reduces rake. Also, getting on the throttle early is also mentally difficult on a high-horsepower bike, especially ones without traction control, because you know in the back of your mind if you get on it too early you could end up getting catapulted by a highside. In an SV-650, the 'Spec Miata' of the bike racing world, you can go almost full WOT at the apex or before, while leaned over, on most corners. Try that on a liter bike (without traction control) and you will most likely be on your head soon after, unless you have God-like (Rossi-like) skill.

So, I'll probably ease into the technique you described above. I am glad to hear you mention trail braking. I hear all the time people in cars talking about getting all of your braking done before you turn into the corner. I never understood why that was the preferred 'go-fast' technique and no one typically talked about trailbraking in cars. On a bike, it is more of an advanced street or a racer technique, but most at least know what it is, and why it is important.

ZX-Tex

iTrader: (15)

Back to the OP Bbundy, sorry I did not mean to jack your thread

Nice swaybar setup by the way. But I digress, again...

So it looks like you are supporting the splitter independent of the nose piece. I have seen one other done this way, and it looks like they are doing it that way in your linked-to DIY article. I like that idea for crashworthiness.

Are you going to glass with one layer on each side, like in the link you posted to?

ZX-Tex

iTrader: (15)

HA I went through the same thing. I tried mounting it to the trunk lid and realized it would not be stiff enough either, also after drilling holes in said trunk lid. I abandoned that and am now fabricating a mount that will attach straight to the vertical frame panel at the back of the trunk. I'll post picts when I get it finished.

I think I might still be able to cosmetically save the trunk lid. But I'm not losing too much sleep over it. It's a race car so function before form.

cjernigan

iTrader: (13)

I work for APR Motorsport (Audi Performance Racing). We race VW GTIs and a 2010 Audi S4 in the Grand AM Koni Challenge series. No rolex racing for us, though many of the Rolex cars and the Mustang Challenge cars had birchwood splitters.
As often as these cars go off at high speed and hit each other in wheel to wheel racing it doesn't make sense to make splitters out of anything expensive when birchwood works well.
Koni Challenge doesn't allow aero so we don't use it on our cars.

turotufas

iTrader: (7)

Damn this thread is giving me crazy ideas. Nice setups!

bbundy

Yep made it 10mm of birch plywood with 1 layer fiberglass top and bottom it looks nice. Im guessing with the fiberglass it is slightly heavyer than 1/2" birch. It is mounted independent of the lower nose piece but I added some U-nuts to the bottom of the GV Toug Run piece to keep it flat to the splitter.

Bob

bbundy

For the rear wing on my car it looks like there is just enough gap to get a 1/8” strip of metal and mount it to the fender in the gap between the trunk lid and the fender.

This picture shows where I’m thinking of mounting. I plan to use 1/8” angle with the uprights mounted just wider than the trunk lid. With 5” risers the trunk still opens enough you can reach inside eve though the wing is fixed.

ZX-Tex

iTrader: (15)

OK got it. Makes sense. That should work nicely and require a lot less fabrication than what I am doing. In fact it makes me wonder if I should change tactics. The wing I have does not have mount points that far out so I would have to add them. But I imagine that adding an insert to the wing would be pretty easy.

Naaahhh... I'll just finish what I have going

ZX-Tex

iTrader: (15)

Makes me think I might blow off the ABS laminate (on a birch plywood core) and try the fiberglass instead. Overall, I think that would be just as easy, if not a little easier. Pros and cons either way.

bbundy

Wing is mounted. Dang I wish I didn’t drill those holes in my trunk lid. This mounting I think works really well. Good solid mount to the chassis. It is a Universal mount GTC200 with double 2.5” risers. Should be up in the clean air.

Splitter is done too. But not painted yet, it’s too freaking cold for paint right now. It didn’t need any other reinforcement square tubing or anything. 10mm birch with single layer of fiberglass top and bottom is stiff as hell. The bolts holding it on come off and go back on easy which is a good thing because I don’t think I can get it on the trailer with the splitter attached. It’s only ~3.5” off the ground. Probably a 15minute job to install both the wing and the splitter putting the car on jack stands.

Still need some kind of wheel spat or something to cover the front of the front tires. Lots of drag and wreckage of downforce going on there I think.

Bob

thesnowboarder

iTrader: (15)

Bob, ive got my gtc200's risers pointed the other direction like so:


I have seen other local miata guys with theirs in the same orientation. Ive gotta cut my wood this weekend and make my splitter now.

ZX-Tex

iTrader: (15)

Bob that car looks great. Really nice overall. That wing mount looks good as well. I am still wishing I had done mine like that now. Damn... And I have 2-3 hours of fab into my mount bracket setup. But then again mine will have four easily removable bolts on the wing mount so I can pull the wing in a couple of minutes, then have a full opening trunk. So probably not a big deal.

Stiff as hell on the splitter, sounds promising. I may try that now. Did you seal the wood with an initial coat of epoxy (like in the link) or go straight to the fiberglass?

With the cold weather it might be tough to get the epoxy to go off outside (too volatile for the garage) but I suppose I could mix a hot batch and/or use a heater.

bbundy

I have 2 risers per side only the bottom one is flipped. I think the wing will be more effective than the splitter so I didn’t feel making the wing stick out further past the back of the car would be any help as it will just start trying to lift the front tires more. It is high enough I think so I didn’t want it further back. I also have a Simpson rear bumper so the back of my car is snubbed off as it is.

Bob

webby459

iTrader: (8)

Bob, that car looks awesome! I think you mentioned going to the flares for the 275s. I just had my fenders pulled hard and rolled in prep for a 275 A6 on a 9" 6UL. Haven't got the wheels yet to try it out, but do you think it can be done without flares? I'm going to be running around 12.25/12.5 with a 550/350 spring, only using the 275 for autocross. The body guy that did the pull came up with a pretty good idea to give me more clearance on the front, I will take pics and out the results if it works.

I am hesitant about the flares as I rock the 8"/225 NT01 combo for normal/track day duty, and would rather a one size fender fits all setup without resorting to sorting out spacers and all.

bbundy

I’m in the same boat with you on the flares.

The 275s on 9" 949's Without spacers there is a whole lot of interference to deal with on the inside. I don’t know how the NB guys seem to make the 275’s work without flares. In the front The ISC front swaybar I have helps allot, a fat Racing beat bar really cuts down wheel cut, but clearance to the wheel well near the shock top both front and rear is still a big issue with my custimized maximized Bump travel and clearance to the A-arm in the front is another issue with wheel cut. Seems like it needs 15mm spacers to get clearance on the inside. It would take allot of pulling in the rear especially to get it to clear. The rear doesn’t really pull very easily although I have been thinking of cutting the inner fender so I can pull the outer fender out then filling up the resultant slot in the inner fender. Seems doable and if It doesn’t work I can cover it up with flares.

I haven’t cut for the flares yet. I’m going to pull the springs off and really figure out the clearance envelope before I start cutting. I’m switching from 550/350 to 700/400 lb springs while I’m at it.

Drove the car to work today. Took a couple back road sweepers at 80-90 mph, car feels planted and noticeably more stable.

Bob

webby459

iTrader: (8)

Aside: mods, can you take the 'newb' off under Bob's uname, it's a brainfuck for me.

Bob, didn't realize it was tape I was looking at holding those flares on. If I repeat what you are seeing with inside clearance, I am going to be fuxored, no way a 15 mil spacer will be kosher with my outer fender clearance. I told him to pull ~1.25", which is to the tenth what I needed based on the math. This was literally all he could get without resorting to the porta-power and sawzall, especially in back. Even worse what you said about the rb/isc bar: I am putting in an RB 1.125 hollow.

Regarding pulling the outer skin of the rear, problem we saw with that is that unless you can hit it hard enough to get the metal to work/stretch, there is nowhere back there to allow the skin to stretch when you flare it, like the give it has in front. Hope this makes sense. My guy proposed making vertical slits in the outer skin, flaring it out to where it worked, then filling in the slits with metal or weld rod if it wasn't too wide.

Again, I will know in the next couple of weeks when my baller 6ULs come in, and I will take lots of pics if there is interest. I can tell you that the 8/225 combo fits in there with lots of room to spare, now! Any idea what kind of spacer is needed to make the 8/225 combo look decent with the flare?

ronmastas

It caught my eye as well. Probably used 6061. Should have used 5 series aluminum.

ronmastas

wow, I didn't realized I was this late to the thread.

Anyhow, I wanted to say hi. I was at the track event hosted by Team Miata 2 years ago * i think* at Reno-Fernley. I think we were the few people from Washington state that made it down there. I was in my ls1 240sx. I was so cheering you on as you had your way with that Ferrari 430. He wasn't a slow driver from watching from the hot pits. Looked like a fun battle. In the last year, I lost my miata virginity and realized how much of an amazing car it was. In hindsight, wish I had a chance to talk to you then. I should hopefully develop a miata for lapping days this upcoming season.
-Ronald

Chris Swearingen

iTrader: (1)

We have gone a long way from splitters, but here is what I did for the rears.

webby459

iTrader: (8)

Chris, I'm just not willing to make that much commitment yet.

So, I will just spend mass amounts of money to get a solution that almost works. Then I'll cut like you did and flare.