Plavan's 818R Build Thread

[Mechie3]

www.onshape.com

Request an invite. From the original makers of solidworks. Free CAD for personal use that uses the same parasolid engine as solidworks (and lots of other CAD programs).

[D Clary]

What ride height did you start with? I kind of set mine up at 3.5" sounds like you could be getting close to 4.5".

[Zach34]

No need for a sway bar. I was thinking going up 10% on all springs. I'm probably going to have to raise the rear another 1/4" or more.

Do you think, geometry-wise, we might end up being better off using the S ride height just for clearance?

[C.Plavan]

What ride height did you start with? I kind of set mine up at 3.5" sounds like you could be getting close to 4.5".

I'm going to remeasure everything/Corner balance before the next race. I think the front was at 3.75 with a quick raise at the track.

Do you think, geometry-wise, we might end up being better off using the S ride height just for clearance?

I was wondering that also- But I'm not near the 4.5" mark.... Yet. I did notice the springs did settle quite a bit. The car was handling great last time out, just the drive train was giving me problems.

[Bob_n_Cincy]

I'm going to remeasure everything/Corner balance before the next race. I think the front was at 3.75 with a quick raise at the track.

I was wondering that also- But I'm not near the 4.5" mark.... Yet. I did notice the springs did settle quite a bit. The car was handling great last time out, just the drive train was giving me problems.

The lift to drag ratio of the diffuser is a lot better at lower ride heights.
Bob

[C.Plavan]

The lift to drag ratio of the diffuser is a lot better at lower ride heights.
Bob

I agree, but rubbing tires is not good at 130-140 MPH.

[Scargo]

That's great data. I had read that 10-12 degrees was ideal. Who the heck can run even 40mm height to maximize force when we might be at 82mm?
BTW, when I had a tiny rub, that I could not perceive, my club black-flagged me in a hurry.

[EODTech87]

What angle is the Factory Five defuser at when installed with a level ride height?

[C.Plavan]

What angle is the Factory Five defuser at when installed with a level ride height?

I never measured- but it seems to be around 10 degrees.

I'm almost done with the complete oil cooler upgrade/ducting. I found some other ducts that I think I can modify for the side vents- If not I will go back to the 3D printed ones. I'm just waiting for those to get here then it will be done.



Anyone know if there is a aluminum piece that bridges the aluminum/front splitter area under the car to under the steering rack? Part number? or am I going to have to make something? It was on my todo list, but I got side tracked and forgot about it until I had to clean all the rubber and track junk out of the front. I want to block it off.


I started playing and printing these NACA ducts. My printer has been on the fritz lately. I need to do some maintenance on it also.


Also wanted to point this out. I have the adjustable rear toe links that were sent with some of the early 818S cars (Rubber Bushing). I planned to upgrade to metal Swag tubes, after seeing this, I bought all the parts to convert the 818R over. The rear rubber has a little too much "give". The tire/wheel was defecting enough to rub. This is with both spacers on the "inside" also to give more clearance (to upper bar). Once I get those rubber bushings out, I'm confident this will not happen anymore. It just means it will be even faster.
Look on the STI pink-


The culprit:

[Mechie3]

There's a thread in the body area iirc where someone has a piece to bridge that gap.

[Scargo]

Are you planning anything for closing the gap between the diffuser and the rear of the chassis pan?

[bstuke]

I have adjustable heim joint connections on all of those points, and the offset lower trailing arm to barely fit the tire on. It does not move a bit.

[C.Plavan]

Are you planning anything for closing the gap between the diffuser and the rear of the chassis pan?

I have already. I took it off to change the oil since I was removing the old oil cooler.

Thanks Mechie, I'll look over there. I also have an email over to Jim to see if I have a missing aluminum peice.

[bstuke]

You might want to just call Jay, pretty sure Jim is at VIR..

[nkw8181]

Are you planning anything for closing the gap between the diffuser and the rear of the chassis pan?

There is a piece of aluminum sheet that comes with the diffuser. If you didn't get it (like me) call ffr and they will send it out.

[C.Plavan]

Here is the rear panel installed I had to call for also.
http://thefactoryfiveforum.com/showt...l=1#post179423

[bstuke]

No scales yet. Maybe this weekend.

I was 1775lb at Dixie.

[C.Plavan]

I was 1775lb at Dixie.

That is really nice. Like I said before, the dry sump, wing mount with integrated bumper, a real intrusion panel, fuel cell, AWIC, complete fire system with an additional hand held fire extinguisher all add weight. Added safety is worth the weight. I need that weight for the ST2 race class. If I was just doing autocross, all that stuff would not be in.

I actually do not mind adding weight since I can just add more HP since it is detuned so much. At the last race, they weighed me coming off the track after the race. I was 4 pounds over my minimum DQ weight .

I'm just happy I have a motor that is still running strong so far unlike the other 818R's road racing. Going 125- 130mph in sustained high G corners lets me know the dry sump is working. I just need to get the oil temp down a bit (Which could of caused some of the other 818 track cars problems also) which I think I have found the answer to.

[Santiago]

At the last race, they weighed me coming off the track after the race. I was 4 pounds over my minimum DQ weight .

SWEET!

Just make sure to eat lunch before the race. =)

[Mitch Wright]

1775 Very nice, my goal of 2000lb with driver water, oil and fuel is obtainable.

[C.Plavan]

1775 Very nice, my goal of 2000lb with driver water, oil and fuel is obtainable.

I'm now 2235 w/driver and 4 gallons of gas...... I weigh 180 as a data point. Good luck!

[C.Plavan]

Air intake upgraded. If I'm not getting cool air now, I have other issues.

[Hindsight]

Looks perfect!

[Scargo]

I think once you're rolling you will be fine. It will be a blast! Some do partition off the filter/intake a little more from the engine compartment.
On the weight issue: I weight 165 and my pistons are 22 grams (each) lighter that stock. My rods are light. My front uprights are lighter and my LCAs will be 3 pounds, each lighter. I've lost the door hinge mounts and lots of other extraneous metal and fiberglass. I'm going to try using an STi intercooler stuck out into the airstream. May be ugly... Dry sump might add weight. I'm planning on being under 2000 with me and 5 gallons.

[Evan78]

Also wanted to point this out. I have the adjustable rear toe links that were sent with some of the early 818S cars (Rubber Bushing). I planned to upgrade to metal Swag tubes, after seeing this, I bought all the parts to convert the 818R over. The rear rubber has a little too much "give". The tire/wheel was defecting enough to rub. This is with both spacers on the "inside" also to give more clearance (to upper bar). Once I get those rubber bushings out, I'm confident this will not happen anymore. It just means it will be even faster.

Do you know how much static clearance you had at that location? I'm wondering how much the tire deflected.

[Scargo]

Oh, the terminology! I think lateral arms (then lateral links) are more standard terms than toe links. If toe, then you could call them camber links, too.
Please understand that I have worked with a (professional) fellow who is a stickler for suspension terminology. I (and he) cannot even get it straight half the time.

[C.Plavan]

Oh, the terminology! I think lateral arms (then lateral links) are more standard terms than toe links. If toe, then you could call them camber links, too.
Please understand that I have worked with a (professional) fellow who is a stickler for suspension terminology. I (and he) cannot even get it straight half the time.

Really? The rear most lateral link is used to adjust toe. Call it what you want. No need to have a discussion about it. Other than Subaru's they are also known as toe links, why? Because they adjust the toe.

[Scargo]

OK, fine. No discussion. Don't get your nickers in a twist.

[C.Plavan]

Just an FYI- Drilling the inner tab mounts for upgrading to 12" swag tubes in the rear is a BIG B. You have to enlarge the holes to 5/8" on the front mount tabs. PITA trying to get a drill in there. I think I'm going to have to die grind the rear hole on both sides (near motor mount) I have tried and angle drill, angle drill attachment with a step drill, filing, grinding- it sucks. nothing can get a straight shot. I'm waiting on some new die grinder bits to have another go at it.
However, drilling the rear hubs to 5/8" was easy.

[Hindsight]

Why do the holes need to be enlarged for longer swag tubes?

[C.Plavan]

Why do the holes need to be enlarged for longer swag tubes?

The rear tabs are 5/8" holes up top "R height", the front tabs are M10 or M12- I can't remember but much smaller than 5/8". I'm not sure if the later chassis are like mine.

You basically need to change everything to 5/8" (hub also) so you can use the standard swag tubes and rod ends. They are a lot cheaper than metric. You can keep limited spares that fit a bunch of places instead of carrying metric and imperial.

It explains what you need in the 818R supplemental, just not how hard it is to drill some holes

[Wayne Presley]

Later R chassis have 5/8" holes on the upper hole and 12mm on the lower hole.

[C.Plavan]

Later R chassis have 5/8" holes on the upper hole and 12mm on the lower hole.

Well that does not help me

[Bob_n_Cincy]

Well that does not help me

Chad
It the original hole was 1/2", could you just add a 1/2 to 5/8 sleeve.
If 12mm these 12mm-16mm sleeve would be very close. http://www.mcmaster.com/#6658k16/=whh9bl
The are about 0.004" to big. Might have to sand them down a smidge.
Bob

[Wayne Presley]

Or put a rod end that threaded 5/8-16 and has a 1/2 hole in the rod end

[C.Plavan]

Or put a rod end that threaded 5/8-16 and has a 1/2 hole in the rod end

That would of been too easy. I like doing things the hard way. I'll just die grind out the front hole.

I was dumb and just tried the rear most tabs first- of course they were 5/8" already. I figured the front ones would be too. My fault.

[Scargo]

I lucked out and got the 5/8" holes... Could you create a stubby 5/8" bit and perhaps grind the flats that would get it into a six-point socket? Or weld it to a socket. I have a 3/8" air ratchet that can get into tight spaces.

[Mitch Wright]

I shortened a 5/8 bit to get the job done, not a problem.

[C.Plavan]

I shortened a 5/8 bit to get the job done, not a problem.

I have tried that, but my angle drills will not fit. What drill are you using?

Great ideas everyone. I'm hoping to get everything done today without it looking like a Hack did it......fingers crossed

[tebriel]

Maybe a pneumatic drill would fit?