Just an FYI I did not use the VSS on my car (Legacy GT trans). Disabled with a Cobb. No issues. My Datalogger provided speed.
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Just an FYI I did not use the VSS on my car (Legacy GT trans). Disabled with a Cobb. No issues. My Datalogger provided speed.
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
You should always mount it as far back and as high as possible. Unless you somehow get the wing forward of the rear axle, all of its downforce will be on the rear (and creating lift on the front.) By moving it up you will get cleaner air, and by moving it back you can run a smaller angle of attack to get the same amount of downforce at the rear tire, which will decrease drag. E.g., Overall downforce is the same, but less drag = more efficient.
ed: Another thing to consider with your design is the exhaust. If it's dumping right underneath your wing you're going to make it nearly useless at WOT.
Last edited by phil1734; 02-26-2018 at 08:41 AM.
Mounting the wing farther back does not allow you to use a smaller angle of attack. The downforce generated by the wing is constant for a given air speed, no matter where its mounted (assuming the wing is in clean air). Mounting the wing closer to the axle center line will however reduce the amount of lift created on the front axles. Reduced front lift translates into less downforce needed from the splitter to counter balance the rear. Less front splitter stickout means less drag = more efficient.
The exhaust may interfere with the center section of the wing. I am not able to run any CFD analysis without a CAD model of the 818R and wind tunnel testing is way beyond my budget. The exhaust is over a foot below the bottom of the wing so I'm hopeful it will not cause too much disruption if any.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Downforce at the wing is the same yes, but the reaction through the chassis to the contact patch is a much different story. You need to consider the entire car as an assembly. There is plenty of literature out there on the subject.
Tufts on the underside of the wing and a go-pro work great should you hit the track and find yourself with rear grip issues under power, though I'm not sure what the solution would be at that point. If you do ever tuft it, make sure to do your decklid as well to make sure the wing isn't creating lift on that.
Either way you should still build the car you want!
Last edited by phil1734; 02-27-2018 at 08:37 AM.
Phil your missing the point that he’s trying to reduce front lift. He’s not trying to maximize the rear downforce but trying to balance the car a little better.
Moving the wing back, creates more leverage at the same load, and will increase front lift slightly (simple lever arm, rear wheels are the fulcrum). Lowering the front ride height, increasing the splitter depth, taping up some air intakes (grill), flat bottoming the car, raising rear ride height (and adjusting the wing accordingly to maintain attack angle) and/or increasing rear spring rate will all decrease front lift. We had a wicked power on understeer in the car, that we seemed to have dialed out by lowering the front of the car (changing to 15" wheels up front) and installing an LSD. Not sure if the LSD had an effect, just us being stupid by changing more than one thing at a time.
I finished creating the wing mount today and test fit the rear deck to be sure everything fits well before finishing the bodywork.
Here are some other pics of the wing installed. You can see my Dad in the background "helping" i.e. supervising and wondering when we are going to lunch
IMG_20180227_114124.jpg IMG_20180227_114112.jpg IMG_20180227_113827.jpg IMG_20180227_103027.jpg
Last edited by Hobby Racer; 02-27-2018 at 06:06 PM.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
When we last left my trans cooler setup, the pump was pumping too much volume and the oil was pooling up in the center diff section of the case, causing the pump to suck the case dry and scavenge air.
I am addressing the pump volume by PWMing the pump power supply to reduce the RPM and thus the volume pumped. To address the pooling issue I attached a short aluminum tube to the the 90 degree bulkhead adapter that goes through the rear block off plate. This deposits the oil just past the center differential chamber, directly into the main case chamber. I had to drill an additional hole into the rear plate as the first one was too high. As an added bonus I now have an inspection hole! If you follow the red arrow in the last picture you can see the tube as it enters the main chamber.
IMG_20180227_141637.jpg IMG_20180227_162204.jpg image101.png
Last edited by Hobby Racer; 02-28-2018 at 08:41 AM.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Hope this mod solves the issue with trans cooler. John, what tires and sizes are you using?
Check your wing height, looks like ours did when we tried to use those mounts. the wing is in the "shadow" of the roll cage and will lose significant downforce. Check out the https://www.youtube.com/watch?v=0xOCYSTQx3E and you can see how chopped up the air is at the wing, from the roll cage. We are over 2" above with ours.
I am starting out with the FFR rims (they were free at the time) and the recommend sizes of 215x40x17 fronts and 255x35x18 rears in Dunlop Direzza ZII Star Spec. I figure I can burn thru these while I'm sorting out the suspension, engine, aero etc. Once I have it dialed in I plan to change to 17" Team Dynamics on all four corners and will decide on the appropriate sized slicks or D.O.T. R compounds at that point.
Mine is 1.5" above the bar, but I also plan to encase the bar in a streamlined airfoil to smooth out the flow.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Good call, couldn't tell in the picture. We are looking into doing the same, but are looking for an existing extrusion die so we don't have to re-invent the wheel.
Might want to think about slotting the rear deck to allow removal with out taking off the wing. Just a thought.Rear deck rear.JPG
Enjoying following your build.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
Sounds like a plan and have done the same thing but the wing is one more thing to take off if just doing a quick check or service. Just a different thought process.
Decided to do something different today. I have been wanting to seal off the front wheel wells better than the supplied FFR pieces allow. So I made some aluminum panels to block off the remaining openings the best I could. The top near the hood will get some of the rubber bulb stripping FFR supplies to close off the gap where it joins the hood. The red arrows point to the panels I made. On the R's at least there are huge gaps, especially where the anti-roll bar comes through. I know from past experience that tons of track rubber, dirt, stones and debris will collect in the front compartment if its not blocked off. I made sure the design allowed for easy access to the grease fittings.
Last edited by Hobby Racer; 03-01-2018 at 07:07 PM.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Sealing off the front wheel wells -
Nice work there and thanks for sharing pix of the planning - that stuff takes time and thinking. I've been expecting I'll want to do this too - your sharing will help a lot.
John,
Nice job on the front end aluminum splash panels.
I have not put any panels in yet. (our car has been drivable for 3 years). Drive it in the rain a lot.
The panels are not on the top of my list.
What is the pros and cons of not installing the panes or wheel wells????
Bob
818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
My Son Michael's Turbo ICE Build X22 http://thefactoryfiveforum.com/showt...rts-818S-Build
My Electric Supercar Build X21 (on hold until winter) http://thefactoryfiveforum.com/showt...e-Build-Thread
Here are my thoughts about installing and improving the splash panels (kind of the opposite list of what you asked for ).
Pros:
- Cleaner front compartment, cockpit, and engine compartment
- Less corrosion on parts and fasteners from exposure to water, dirt, etc.
- Possible aero advantage (but I'm just guessing here)
Cons:
- Access to components for maintenance and repair can be more difficult if not planned carefully
- Added weight, but not really much, the aluminum panels are very light
- Takes longer to get the car finished and ready to drive
In the end I guess its just that I like a more OEM fit and finish, I can be quite particular about things. It does slow my progress down quite often though.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Last edited by Bob_n_Cincy; 03-02-2018 at 10:54 AM.
818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
My Son Michael's Turbo ICE Build X22 http://thefactoryfiveforum.com/showt...rts-818S-Build
My Electric Supercar Build X21 (on hold until winter) http://thefactoryfiveforum.com/showt...e-Build-Thread
we have not done anything on that yet, will probably only do one in the front of the tire, as our light box was full of rubber....not a little, but FULL, after only a few sessions. Need to get the car back from the engine builder first....11k later
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
After more than 3 months of hounding the MS3 developers, they finally emailed me a beta firmware containing the software fix I wrote for the ECU and it works! Now I can actually start tuning the motor, that is after I get the body painted
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Congratulations
If you like the Exhaust Note, try this.
I've been busy sanding and sanding and sanding, and then sanding some more. It just never seems to end. But I'm seeing the light through the dust cloud. I'm hoping to shoot the first coat of primer next week. Found lots of voids between the gel-coat and the fiberglass, mostly on the sharp corners where its hard to get the glass to tuck in tight. I also cut off nearly 1/2" from the driver side front fender, at the nose where the fender joins the front fascia piece. They are not made symmetrical from FFR and look funny if you don't correct it. The body work is definitely the most daunting part of the project in my opinion.
My temporary paint booth is saving the rest of my garage from being covered in gel-coat and body filler dust.
IMG_20180320_162951.jpg IMG_20180320_162936.jpg
Last edited by Hobby Racer; 03-22-2018 at 05:19 PM.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Now that paint work is nearing I have to settle on a paint color. I think I want to go with a burnt copper orange for the body. Accented with a gloss black center for the hood, covering the radiator exits, and gloss black humps on the rear deck. Here are some samples of the body colors I've found and like so far.
2005 Dodge Viper Copper Head Orange
2005 Dodge Viper Copper Head Orange1.jpg
Mercedes-Benz AMG GT3 Battlefield 1 Burnt Copper Orange
Mercedes-Benz AMG GT3 Battlefield 1 Burnt Copper orange.jpg
I like the Mercedes color better but I can not find any information on the paint codes anywhere! If anybody has any information on this or a similar color let me know!
Last edited by Hobby Racer; 03-20-2018 at 06:11 PM.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
I like your color choice. Check out House of Colors they have a very similar shade.
I can't find it it was mentioned. How is your new configuration shifter feel compared to the aluminum FFR shifter going out front?
Excellent. The shifts are crisp and there is no slop to make it hard to tell what gear your in. You can actually feel the shifter detents in the trans when rowing the gears. One thing I will change is to make the throws longer. I have them so close now you can hit 5th when shifting from 2nd to 3rd if you push side ways too hard. Luckily the side to side and front to back throws are adjustable.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Any size you want. You could get the "T" handle ones if you wanted. If you are worried about scratches, a little clear bra vinyl on the spots would alleviate that concern. https://www.mcmaster.com/#standard-q...-pins/=1ca4nya
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
Definitely looking forward to this one coming together!
Paint arrives on Friday! Hoping to paint next week. Pics to follow if everything goes well.
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
I had hoped to have all the painting completed by the weekend, but as usual life had other plans. I did manage to get the more difficult two tone pieces painted though. Plus a few black only bits that are not shown here.
For those painting your own cars or just looking for good paint at a reasonable price, check out The Coating Store. My friend who is into street rods turned me on to it instead of the local paint supply shop. Saved almost a grand over what the local shop wanted to charge for similar materials! So far the quality seems excellent.
This is Copper Pearl and Jet Black
MK3.1 Roadster completed 2011
818R built with EZ36R H6 completed 2018
818R rebuild with a JDM Honda K24A
Looks great and nice "booth" you built. As a painter I can appreciate the work. Congrats.
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)