480WHP Honeywell Garrett Powered F20C: Devin Giles' Time Attack S2000

by Khiem Dinh

Photos Provided by Devin Giles

It all starts the same way. “I want to go auto-crossing!” you say. So, you start browsing the interwebs and research the S2000. You start auto-crossing and start modding and moving through the classes. Then, you do a track day. Then, you mod the car some more. Then, you do time attack. Then, you end up with a highly built race car like Devin Giles- owner and driver of this fast S2000. It’s a familiar path; there’s probably a support group for it out there.

Devin’s car had made it to pretty-fast stage with mostly bolt-on mods. But, he wanted to go faster, of course, and that required more power. So, a Honeywell Garrett turbo was employed. With power out of the way, the car was lacking grip. At this point, Professional Awesome was called in to come up with some aero solutions that Devin could build. 


Professional Awesome provided the splitter design that was easy to fabricate. It features a nice vertical surface to build up the stagnation pressure, end plates to control the airflow at the ends of the splitter, and diffusers to reduce the pressure underneath. The eyehooks provide attachment points to make sure all the downforce created by the splitter is transferred to the chassis. 


The rear aero setup was also under the guidance of Professional Awesome. The Kognition rear wing uses KazeSpec mounts to tie straight down to the chassis; no one wants a trunk mounted wing that can fail, as the end result is usually pretty bad. The deck lid rear spoiler with Gurney flap works in conjunction with the rear wing. 


Turbo S2000s that are tracked on road courses often have overheating issues with the traditional stacked intercooler/radiator setup due to the lack of frontal opening area. A solution is to go with a V-mount setup. A CSF radiator is placed down low and the Garrett intercooler forms the upper half of the V. The radiator and intercooler have shrouds to force all the air through the two heat exchangers. 


Page 1 of 4 Next Page
Bookmark and Share
Tuesday, December 12, 2017 10:13 PM
did you do any back to back testing with the fender cutting mod I kinda wanna do it to my Miata but don't really wanna do it if it doesn't actually benefit me
Thursday, December 14, 2017 8:32 AM
@warmmilk, my thought is aero mods are always speed dependent. The higher the speed, the more they do. With the Miata being a low hp car, I don't think there'd be a lot go gain. Will there be gains? yeah, but not sure there's enough to make me want to hack up the fenders. BUT, if you are trying to eek out every fraction of a second, go at it!

I'm sure you know of Morpheus:
Thursday, December 14, 2017 11:25 AM
I was thinking to make mine a little prettier than just cutting it off like on the s2k, but not quite up to morpheus levels since I don't know how to do carbon fiber...

I was thinking to attempt something closer to this, seams easier to do than the carbon one and looks better than Devin's
Friday, December 15, 2017 11:39 AM
So something along the lines of the Victory Function type fender:
Friday, December 15, 2017 1:42 PM
yes, exactly
Friday, December 15, 2017 1:54 PM
how come the second part of that article never happened? where they test it...?
Saturday, December 16, 2017 9:32 AM
There are a few ways you can test ideas. One way to measure downforce and drag are as follows.

To measure the effects of drag, find a very long straight road. Take the car up to a certain test speed (ie 80 mph), then put the car in neutral and let it slow down naturally to a low speed (is 50 mph). Time and record the amount of time it takes to slow down in neutral. Do this mutiple times in either direction, and average the results for each direction. Repeat the test for different configurations (so say you would do multiple runs with a full fender, and then multiple runs with cut fender). Compare the averaged times, if the full fender case has a longer time than the cut fender case then you have decreased drag. To know how much drag you've added or lost is a little more involved and you'll have to do research on a method called "Coast Down Testing"

One way to measure downforce (in a low-buck way) is to :
1. Add 4 rotary potentiometers to the suspension of you car. You'll have to set it up so that it the full range of motion of the suspension (from droop to compression) is captured by the sensor. Rotary pots can be found in many things, for example an older 3 wire throttle position sensor.
2. You'll have to read in their outputs into a datalogger. AEM makes a great one, the AQ1. Or, for a low buck alternative read them into an Arduino with a SD card shield installed (lots of articles online on how to do that)
3. Once you have the rotary pots and logger installed on your car you'll have to calibrate them by measuring the damper displacement at different points and the corresponding electrical voltage that your sensors make. Then make a curve that tells you damper displacement for sensor voltage (you can do this in excel).
4. Once you've got everything all set up, go back to that long road and log the sensor voltages while you hold the car at a set speed. Again do this multiple times in either direction.
5.Once done, park the car and record the resting voltage readout on the sensor.
6.At home, take your logged data file and first subtract the at rest sensor voltages from the sensor voltages while the car was moving.
7. Take these voltages and apply them to the calibration curve you made. You will now have a table of suspension displacements at speed. Find out the spring rate one your car and multiply the suspension displacement value you found by the spring rate.
8. Now you have the amount of downforce on all four sides

The above method sounds like a lot of work at first but consider this: the setup I mentioned above can probably be done for under $100 in a low buck way, and around $600-1000 in a more refined way (can be done for even more than that, just depends on how precise you want to be). But that say $100 investment and time investment now gives you the ability to precisely know if you've added or reduced downforce on the car, and what the distribution is. Furthermore, if since you're measuring suspension displacment, you can also now calculate shock velocities and do force vs velocity curves for damper tuning ;)

Lots of cool things that can be done on grassroots budgets, just wish more people knew how/cared to try. Perhaps I need to do a how to article in the future.

Mike Kojima
Mike Kojimalink
Sunday, December 17, 2017 8:43 PM
Rami! Work on our articles! Your posts are great!
Tuesday, December 19, 2017 9:12 AM
Hi Mike,

Thanks a lot! I've been planning on writing some, but grad school has kept me busy. Hoping to do some soon, however.

Monday, December 25, 2017 11:09 PM
Post Comment Login or register to post a comment.

MotoIQ Proudly Presents Our Partners:

© 2018 MotoIQ.com