Plavan's 818R Build Thread

Had a team of race mechanics come over and help me bleed the system. But nothing different than what we have been doing. Also had the endurance FFR GTM team guys come over and give some tips. We did find out the second fan has not been kicking on. Figures I forgot my computer to access and turn it on. The tuner must of forgot. We are hardwiring it right now.
I'm hoping that will help, but I'm not that confident. Maybe my tune is too much for the cooling system. I don't know.

Another Subie racer came by and looked for signs of a blown head gasket while we were burping it again. Nothing out of the ordinary he says.

I wonder how the FFR cars do. I have not seen video or article since the last one they blew up. You would think that they have some information to share so that we all don't have to play trial and error

Heat, heat heat is the 818's biggest issue. I am very sorry to hear about the high temps, hopefully you can get it figured out.

Chad
Sent you a PM.
Bob

Good news- I found out what all the 818R guys are going to have to do for the motor cooling. I'll take pictures. Last two sessions it did not get over 208. It was a combination of getting the second fan working, and getting more airflow. You can't tape off the bottom open area above the splitter. FFR wants you to tape it up for more front downforce-. I left it partially open to feed air and bent up the three precut vents aiming at HE and radiator. This is the aluminum radiator floor.

Now the the problem is the oil temp. Creeps up to 260 after 7 laps. I have to come in, park and cool it off. It's a blast during those 5 laps where the oil temps are down. I dropped another 2 seconds to 1:54 on junk tires (no need to waste the good ones)

I can't fix the oil cooler ducting here. I'm going to need to fab up aluminum side scoops to grab more air, and box off the cooler from the motor totally. Keep in mind I am running hatch less right now also.

Two of three problems are fixed

Do you still have the oil cooler in the rear, mounted off the cross brace?

I'm starting to wish I had gotten the cooler with built in fans like you have.

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Originally Posted by metros

Do you still have the oil cooler in the rear, mounted off the cross brace?

I'm starting to wish I had gotten the cooler with built in fans like you have.

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Yes- with 3" duct tubes from both side vents feeding cool air.

Very interesting! I was thinking the slit in the front might be relevant for the radiator.
Thanks for all the feedback, Mr. Guinea Pig. Best of luck.

Glad to hear you got some of the gremlins under control.
I feel mechies front hood louvers and vraptors side scoop louvers will be extremely beneficial.

We found out the side vents are worthless for air flow with the door vent add on. The air flow is so fast coming out, it is bypassing the side vents down stream. We need BIG side scoops to make any use of the side vents. I'm going to box in the oil cooler in its current location. I'll need fab up some big aluminum side scoops.

Very interesting...

Thanks for keeping us in the loop with your findings Chad.

Best,
-j

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Originally Posted by D Clary

I wonder how the FFR cars do. I have not seen video or article since the last one they blew up. You would think that they have some information to share so that we all don't have to play trial and error

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Just looked over Chad's last few build pages. One striking difference between his build and the current grey FFR-mule is that they cut out a much larger portion of the hood area where Chad still has only the conventional grill area exposed. Mechie's louvers may help, but I wouldn't be surprised at all if what is really called for is similar wholesale removal of lots of that area of the hood.

What I read from Chad's experience is that airflow is key - however you can get that, be it additional fans, vents, or louvers, the basic set-up is not sufficient. You might be able to get away with what we see is on the grey FFR-mule and retain the greater downforce of taping off the lower nose vent. Of course, we need another guinea pig to find out. ;)

Best,
-j

And you wonder why mid engine exotics have huge vents and ducting. I was pushing FFR to do more aggressive ducting in the design phase to match the "looks" of other mid engined cars. Little did I know at the time that other manufacturers probably did it for a reason...air flow.

I bet the new hardtop with the roof vent will get some good flow to the engine bay. It should also help pull some air down over the engine bay and provide more low pressure in the rear?

Keep in mind that the Grey FFR 818R is using the restrictive, FFR provided mesh material. It also has not been on the track very long, or lately.

It wasn't a problem of getting the air out, it was a problem of getting air in to the radiator. It just needed more with the HE in there too. The door vents extract most of the air. It's probably causing turbulence down the side that makes the side vents ineffective (proven from my air intake temps when I had the air filter down there). The side vents really are not big enough for a race car. Plus, they just hit the 90 degree aluminum wheel well insert. Not very effective.

Chad, how are the door vents getting air out? There's aluminum panels covering the frame aft of the radiator. The only way for that heated air to release out the door vents is if it is spilling over the aluminum panels...then down towards the door vent openings. That's hardly a well designed flow path.

I'd love to see better pics, but from what I can tell, the door vents are only serving to release the turbulent air of the wheel well (which is largely blocked off from the radiator flow). This is what I'm seeing: Attachment 40791 The radiator is totally blocked off along the side with only a little bit of room above the UCA. So the door vents aren't positioned to assist heat extraction here.

Releasing turbulent air in the wheel well will benefit drag, aid in cooling the brakes, and possibly benefit downforce (and perhaps also creating poor flow conditions to the rear vents), but I'm not seeing the radiator cooling benefit. What am I missing?

Best,
-j

I believe Chad said with the door vents you have to remove that piece. Chad has my original small louvers, but not the big ones.

The side vents don't even stick out from the side of the car much regardless of turbulent air from the door vents. Looking down the front they're almost flush with the front fenders. They don't stick out as much as they dive into the body, thus missing most of the airstream.

Hi Mechie, yeah I was talking of your larger ones. I think they will help. I plan to line the area after the radiator with sheet metal to direct air up through your vents.

Quote:

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Originally Posted by Santiago

Chad, how are the door vents getting air out? There's aluminum panels covering the frame aft of the radiator. The only way for that heated air to release out the door vents is if it is spilling over the aluminum panels...then down towards the door vent openings. That's hardly a well designed flow path.

I'd love to see better pics, but from what I can tell, the door vents are only serving to release the turbulent air of the wheel well (which is largely blocked off from the radiator flow). This is what I'm seeing: Attachment 40791 The radiator is totally blocked off along the side with only a little bit of room above the UCA. So the door vents aren't positioned to assist heat extraction here.

Releasing turbulent air in the wheel well will benefit drag, aid in cooling the brakes, and possibly benefit downforce (and perhaps also creating poor flow conditions to the rear vents), but I'm not seeing the radiator cooling benefit. What am I missing?

Best,
-j

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Mechie nailed it. With the door vents, you leave off the back wheel well pieces so radiator air can escape. FFR said to leave off the very back piece, I went a step further and left off the little triangle piece in front of the rear most piece also. I'll take more pictures after I unload the car from the trailer.

Does this mean that all production cars and pure race cars with similar side vents perform poorly? I'm guessing not, and that functionality is somewhat dependent on the front aerodynamics (as has been mentioned) rather than how far it sticks out in front of the wheel-well. Perhaps canards could help?
In the front, perhaps more emphasis placed on the hood's vents being larger and more air exiting there? Perhaps the side openings of the front fenders be made larger and the door not be blunt in the front, so that airflow is not moving as fast and as turbulently on exit? I have trimmed back the vertical lip on the rear of the front fender till it is almost flush to the inside. I moved the front of the doors in (more than normal). I have created about as big an opening as I can in that area.
At the rear, I plan on bringing the face of the rear side opening in by cutting it top and bottom, vertically scoring the inside of the front-most area, so it will bend (hard against the frame at the back), and then re-glassing it top and bottom.

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Originally Posted by Scargo

At the rear, I plan on bringing the face of the rear side opening in by cutting it top and bottom, vertically scoring the inside of the front-most area, so it will bend (hard against the frame at the back), and then re-glassing it top and bottom.

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To get more air in the rear compartment, I am also going to open up the side vents by recessing the input to the vent. Similar to this picture.

Attachment 40809

Chad,
I am banking on the rear bumper cutouts sucking air out of the motor compartment. Does that seem to be working?
Bob

The other problem is the stock ffr vents are cut too small and the grill mil isn't open
enough. It created a wall that forced the air out and around. Open the vent and get a low pressure area behind it. The rear grill also needs to open up more. The radiator area has similar airflow issues with no area for air to escape. Between the bigger vent louvers and a divider in front of the battery compartment... :eek:

Thanks for the info Chad - I'd love to see a clear picture of how they set it up.

Flow to the rear side scoop is definitely hindered by the block profile of the front door, but the FFR cut-outs alleviate this a lot. So there's something else leading to either poor flow in the region or maybe the entrance is too small. I do like Glyn and Bob's proposal, but I worry that the flow path itself is just not working for the area without pushing further out from the body to catch something. Of course, there are other solutions...well placed canards might do it, but it's guess and check under dicey conditions (absent a wind-tunnel); then again, there's also barge boards which would likely be the best solution.

Best,
-j

Chad where did you post the 1:54? BW 13CW? If so that's darn fast with 280HP!! Incredible actually.
Sorry about the cooling issues but glad it's all holding together why you're working it all out.

Quote:

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Originally Posted by Bob_n_Cincy

To get more air in the rear compartment, I am also going to open up the side vents by recessing the input to the vent. Similar to this picture.

Attachment 40809

Chad,
I am banking on the rear bumper cutouts sucking air out of the motor compartment. Does that seem to be working?
Bob

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The rear of the 818R is the hottest thing I have ever felt. You have your work cut out putting a radiator behind the motor, its soooo darn hot even with my two rear cut outs. I can't imagine blocking flow with an radiator back there. The motor/exhaust/turbo pump out heat, and I have ceramic coated stuff AND header wrap. I'm going to have to box in my oil cooler back there to keep the heat out.

Quote:

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Originally Posted by Brando

Chad where did you post the 1:54? BW 13CW? If so that's darn fast with 280HP!! Incredible actually.
Sorry about the cooling issues but glad it's all holding together why you're working it all out.

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Thanks Brandon- Yep CW13. I was pretty excited. Then a ST2 Corvette ran a 1:48..... Once I get it running well, I wont drive like a sissy looking at the gauges all the time. It really messes up my lines.

Oil temps are the only thing I need to work on now. Once That is done, It's on to the handling. I would prefer stiffer springs. There is a little too much roll for me.

1:48 for ST2? Jeez I had no idea guys from ST2 would be running that fast. I have this thing about running faster than the Lotus 211, and the fastest time I have seen posted is a 1:50 with that track config and your almost there. I ran a 1:58 there with 40 more HP than you and I can't imagine how I would have shaved 4 seconds. You're rockin it. Were you running R6's still or did you shift to A's?

Quote:

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Originally Posted by C.Plavan

The rear of the 818R is the hottest thing I have ever felt. You have your work cut out putting a radiator behind the motor, its soooo darn hot even with my two rear cut outs. I can't imagine blocking flow with an radiator back there. The motor/exhaust/turbo pump out heat, and I have ceramic coated stuff AND header wrap. I'm going to have to box in my oil cooler back there to keep the heat out.

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Hi Chad,
My radiators should not add any heat to the engine compartment. As that heat will get blown out the back immediately.
The two 12" radiator fans should exchange the air in the engine compartment every few seconds to prevent much of a heat rise.
The only down side it that I may be blowing warm air through the radiator.
I will have a small 6" fan that will run on a sensor/timer after the car is turned off to keep the compartment from heat soaking.

Thanks for doing all your testing and giving myself and others information to watch out for.
Bob

I would highly suggest upgrading to a proven radiator. With my Ron Davis and near 100 degree ambient temperatures, the highest I saw on a 15+ minute track session was 196. That may have even been after I pulled off track and was cooling down in the paddock. 196 is when I have the fans turning on.

Quote:

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Originally Posted by Brando

1:48 for ST2? Jeez I had no idea guys from ST2 would be running that fast. I have this thing about running faster than the Lotus 211, and the fastest time I have seen posted is a 1:50 with that track config and your almost there. I ran a 1:58 there with 40 more HP than you and I can't imagine how I would have shaved 4 seconds. You're rockin it. Were you running R6's still or did you shift to A's?

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I was using my old R7's- I have a set of new A7's I did not mount yet. There was no need to waste them until the car is running right.

Quote:

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Originally Posted by Bob_n_Cincy

Hi Chad,
My radiators should not add any heat to the engine compartment. As that heat will get blown out the back immediately.
The two 12" radiator fans should exchange the air in the engine compartment every few seconds to prevent much of a heat rise.
The only down side it that I may be blowing warm air through the radiator.
I will have a small 6" fan that will run on a sensor/timer after the car is turned off to keep the compartment from heat soaking.

Thanks for doing all your testing and giving myself and others information to watch out for.
Bob

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That's what I meant, all that hot air going through the radiator. I could not keep the engine compartment cool with the rear hatch off (humps). It still caused my oil cooler to get too hot.

BTW- Everyone loved how my car would throw flames on shifts. :)

I second a quality racing radiator like what Ron Davis makes. 3-4 times thicker than stock.
If you think about it, all of the exhaust, the engine and the tranny are all in that space. The tranny gets hot. Even when moving there is very likely some dead-air spots back there in the stock kit configuration. I do not care for the idea of anything in the back working off pre-heated air; certainly not the radiator. Segregating it and supplying it with fresh air seems impractical.

Enjoy- Here are a few laps before I had to pull off due to rising oil temps.

http://youtu.be/Mbcc5Uiinz0

Chad, did you wrap/coat your exhaust or just the header and uppipe?

also, what about going old school with the oil cooler and just hanging it on the top of the car between the humps?

Attachment 40839

Quote:

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Originally Posted by longislandwrx

Chad, did you wrap/coat your exhaust or just the header and uppipe?

also, what about going old school with the oil cooler and just hanging it on the top of the car between the humps?

Attachment 40839

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Everything exhaust related is ceramic coated and wrapped.

I thought about that for the oil cooler, but want to try and box it in first to keep engine heat out. Throwing it between the humps would be a last resort thing I think.

Love the video!

Thanks for the video! On old tires, Tracmate seems to indicate that you were often in the area between 1.25 and 1.5 g's in turns. Is this for real? Do you have a datalog that has real numbers? Seems like it might indicate that you are getting aero benefits.
Mentioned by Andrew and Tamra, they had to be very judicious with the application of throttle to keep the rear end from taking off on them.
Seemed like you had plenty of power coming out of turns. Can you elaborate on how smoothly the torque curve works, its predictability and tire traction vs power.

Looks great chad. The new tires are really going to help, I can see the grip just isn't there. As far as the engine compartment, does the air flow through or does it ball up behind the car and stall in the engine bay. I don't recall that being looked at on the early wind tunnel test. Maybe a blower drawing from the side scoop to promote some flow. With the inner fenders and belly pan, the engine is running in a box. It will be hard to control oil temp under those conditions.

Thanks for sharing the video Chad.
I am not to the point yet to know if I go with plan A or B yet for my radiator exhaust vents, I need to measure up a car with the body on it to get an idea of the space I have to work with. this is Option A I am exploring for my radiator exhaust in the hood.
Attachment 40843

Thanks Guys- I have been putting a lot of time, thought, and cash into this car. I'm now sort of realizing, I am the Factory Five 818R Mule/test car. Not something I was really hoping for. I do hope FFR will start racing the 818R's again. Especially before coming out with more "new" 818 stuff.

That being said, I may be going "Radio Silent" for awhile to focus on getting this car all setup and reliable. Once I make some major headway, I will publish a "818R Manifesto" for everyone. Sort of like a "Cliff Notes" version instead of people having to go through pages and pages in my build thread. I'm glad to help in anyway I can, so shoot me a PM if you have a specific question.