Sean's GT3 Inspired NA Miata

Miata Parts, Intakes, Superchargers, Headers, Exhausts, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
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Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

As a part of the Good-Win-Racing team, I wanted to take some time to introduce myself and my car on the forum. I started autocrossing in 2007 through the San Diego BMWCCA and I've been hooked on the sport every since. My first autocross car was my faithful 2.8L BMW Z3.
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After a few seasons of autocross, I picked up my first Miata in 2010. Over the last 5 years it has been through many revisions. When I first bought my Miata it only had some basic suspension, exhaust and a rollbar.
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Like many I got the power bug and decided to turbo my Miata. I used a T25 turbo and it provided lots of torque. With it's quick spool, the car was a handful at the autocross.
https://www.youtube.com/watch?v=MjC511VGp3k

After a few years of autocross I decided to take the Miata to the big track. My frist track day was at Auto Club Speedway in 2011.
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It didn't take long for the turbo to wear out it's welcome. I had multiple turbo stud to manifold failures despite applying many well known fixes. In 2012 I pulled the turbo out in favor of a NB1 1.8 for some reliable track day fun. Since then the motor has been very reliable and made a healthy 140whp on pump gas. Now the car is tuned with E85 and makes around 150whp.
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During 2013 I competed in the complete season of Miata Challenge and won the Modified Class! During 2013 I also began adding aerodynamic components to get as much grip as possible from my street tires.
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I put together a little video highlighting the track days from Miata Challenge in 2013.
https://www.youtube.com/watch?v=QizWUqwFEyE

Last year I attended the Global Time Attack: Super Lap Battle to watch the spectacle. With nearly every car producingat least 350whp, there wasn't a chance for me to place.
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Moving forward with this year I am excited to get the car some much needed upgrades under the hood and continue to develop the aero.

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Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

While everyone I know was at Chuckwalla for Miata Challenge...I decided it was time to get started with the car.
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I stripped the logos off the car, it's time to refresh the paint and re-do the livery.
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FatCat's have done their job, they are going home to their new owner this week.
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These are the new Feal 441 Road Race coilovers with custom valving and spring rates. The new rear top hats make me excited, the lack of rear shock travel has really been something I've wanted to fix.
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Hit a little snag swapping the suspension this time, the axle boot split in half so Rocky had to order a replacement boot and grease. Yesterday went much slower than anticipated.
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Today went much smoother, got the front suspension swapped and started on the supercharger bracket.
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Without powersteering or A/C, mounting the Rotrex bracket took less than 15 minutes.
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Mocking up the Rotrex to test some intercooler piping ideas. Going to swap back to a 5 speed tomorrow and do the clutch (ACT Stage 1 Heavy Duty Organic ).
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Freescopesdad
Posts: 112
Joined: Thu Feb 23, 2012 9:42 pm

Re: Sean's GT3 Inspired NA Miata

Post by Freescopesdad »

Great start Sean. Waiting for the green GT3 wheels... 8)
Ron Petrich
http://www.sacramentoareamiata.org
2016 ND GT 6MT|ZII/NT01|Ohlins|Progress|OFT|HDDDM4
Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

Freescopesdad wrote:Great start Sean. Waiting for the green GT3 wheels... 8)
It's not out of the realm of possibility, I've considered some wheels that'd match my roll bar on more than one occasion. :D

Today I pulled the radiator to look at intercooler mounting solutions with Ryan and one of the fittings decided to strip out. I'm not entirely sad as we just got a new shipment of CSF B-Tube 42mm radiators in today. Can't say much bad about the CXRacing as it got the job done for the past 4 years.
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CSF is a really nice unit and should cool MUCH better than the 55mm CXRacing Core. Koyo is reporting their 36mm Hyper-V Core (similar B-Tube fin and increased fin density) cools better than their outgoing 52mm. Koyo's old 52mm is similar to the CXRacing unit in terms of cooling capacity.
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The original plan was the mount the intercooler up high and notch the radiator support to give the intercooler pipes a clear pathway. Ryan had other ideas for mounting!
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We decided to go with a "v-mount" style in front of the radiator. Given the large number of hood vents and the intercooler size ( 28"X5.5"X2.5") it worked out rather well.
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Mounting is very simple, two small brackets up front and the majority of the weight is supported by the end tanks. Rubber trim and the coupler should isolate vibration fairly well. An added benefit of the intercooler size is a good majority of the cooler is left unobstructed with the bumper trimmed. Tomorrow will involve mounting the engine oil cooler and rotrex. Gotta get this car off the lift and rolling before the tech day!
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Brian
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Re: Sean's GT3 Inspired NA Miata

Post by Brian »

Good stuff Guys, looks like the Intercooler was custom made for that spot.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Freescopesdad
Posts: 112
Joined: Thu Feb 23, 2012 9:42 pm

Re: Sean's GT3 Inspired NA Miata

Post by Freescopesdad »

Do you have to do anything special to direct air into the IC (scoop etc)?
Ron Petrich
http://www.sacramentoareamiata.org
2016 ND GT 6MT|ZII/NT01|Ohlins|Progress|OFT|HDDDM4
Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

Brian wrote:Good stuff Guys, looks like the Intercooler was custom made for that spot.
:D We definitely got lucky on this one, can't wait to test this in the desert heat @ Chuckwalla next month.
Freescopesdad wrote:Do you have to do anything special to direct air into the IC (scoop etc)?
Not yet, as long as all the gaps are sealed up at the top and on the sides the pressure inside the mouth should do all the work. For the exit we are going to see how my heavily vented hood does, if the data looks good then it will stay. Otherwise we will plumb the exit of the inter-cooler with it's own dedicated hood vent.

I also mounted my brake duct inlets inside the radiator mouth , another bonus of having the brake ducts mounted inside the mouth is reduced drag.

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We also worked on the oil cooler and Rotrex oil cooler mounting. These will be mounted as a mirror of each other on each side of the radiator. With a large portion of the radiator exposed still and the intercooler up top 20 minute track sessions shouldn't be a problem.
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Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

Finally got this project off the lift last week! Once we had the heat exchangers mounted and the line routing finished, we moved onto intercooler piping. One 90* aluminum bend and one straight piece of pipe was all it took with carefully chosen couplers. The BPV on the hot side will get replaced at some point in the future as it vents at idle, by design as a bypass valve.

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First start video can be seen below:
https://www.youtube.com/watch?v=lwwRehdOzGM

Once I got it home, Ryan helped fabricate some head light mounts so I could get to the dyno in the evening after work.
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I also picked up some Hoosier R80s from a tuning client, going to use these up at Chuckwalla in the begining of May. Once I get the alternator replaced on my car, found out it was dying during street tuning, I'll hit the dyno with the Rotrex to get some numbers!
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Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

Last weekend I had a few projects to tackle to get ready for another autocross. First order of business was addressing the brakes. PFC pads, Wilwood 1" master cylinder (soon to be available through Good-Win Racing) and 1.8 rear brakes to further improve balance.Image

Installation of the brake master is a bit challenging as it takes some time to bench bleed properly and route the lines. However, the effort is well worth the result. Brake pedal effort increases but pedal travel decreases due to increased hydraulic advantage.
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While we had the car on the lift, we also threw on a fresh set of V8 Roadster frame rails. My frame rails have seen better days between curbs, speed bumps and loading the car on the U-Haul trailer. Installation is fairly straight forward, although you do need to mount the hard lines on the passenger side. On the road, the car does feel less busy over rough terrain.
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After staring at my new APR GT-250 wing for a few weeks, it was time to start the process on creating a mounting solution. Can't wait for this to go on the car, it'll mean I'm one step closer to paint!
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And in another episode of tales from the dyno, I got to play with a very fun turbo Mustang. Built 408 Windsor block and it ran out of injector at 513whp with 12psi of boost. This set up is supposed to be good for a solid 800whp.
Sean @ GWR
Posts: 79
Joined: Wed Oct 22, 2014 12:55 pm

Re: Sean's GT3 Inspired NA Miata

Post by Sean @ GWR »

MRLS prep is in full swing at GWR. I wanted to post this update yesterday, but I was dead after 30 hours in the shop this weekend. Time is running out before Ryan starts his project so we tackled the splitter, ducting and bushings all in one weekend!
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Using Ryan's old splitter as a template, he was able to make quick work of the 1/2" birch from Home Depot Motorsports. The primary goal of this splitter is build it max for street class rules in Redline Time Attack and Global Time Attack.
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One of my requirements for the splitter was a quick removal process for trailer loading and unloading. Ryan came up with this super slick design that has weld on receivers on the car that the splitter frame attaches with two pins on each side. The back of the splitter also slots onto the subframe with a steal plate stays with the splitter for additional support.
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While Ryan worked on the splitter, I continued to install bushings. This is NOT a trivial job and without a press it is not worth attempting. While swapping the bushings, I also ordered all new alignment bolts. Super happy I did, nearly every one on the car was rounded out.
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For fun, we threw the street bumper on and it surprisingly fit! However, for this project we are using a separate bumper, with EP air dam, and ducting. The goal is have modularity for the car. I can take the splitter/ducting off and quickly convert it to street use if I so choose. Despite the pure track focus, the car is absolutely awesome on the street.
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With a wood splitter, it is important to seal it so oil can't soak in and cause a fire hazard. We used fiberglass from a local source and inexpensive resin. With this needing to dry over night, we called it for the first day with a total work time was 13.5 hours.
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Day 2 started with only a few more bushings to go, all the ducting and the air dam! We knew it was going to be another long day.
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Many hours later the ducting was starting to come to shape. By building the ducting and fence for the air dam first, we are able to make the air dam fit much better against the duct.
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Inside the ducting, everything seals up perfectly. Anyone who runs forced induction at the track knows the importance of ducting to keep temperatures in check. The main portion of this ducting stays with this splitter! Two additional pieces were made to seal the walls up, but those stay on the car...keeping both the street ducting and track ducting sealed!
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With the majority of the splitter/ducting complete, we moved to making the air dam. First we roughly cut the bumper and made a series of tedious measurements to determine where to cut everything.
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We also made the mistake of not laying the plastic out in the sun, this made it a bit more difficult to work with. When riveting the plastic to the bumper, you must use back up washers with the plastic rivets so they do not rip through.
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Here is a complete shot of the ducting and splitter. With the bumper on the car, it takes a total of 60 seconds to remove the bumper AND splitter! It also only takes 30 minutes to change the car from time attack use to street use.
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And finally, a complete shot of the air dam on the car! I'm a little biased but...this is by far one of my favorite iterations of the EP style air dam.
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Overall, I couldn't be happier with the results. I finally have the front aero to match the GT-250 which will be going on the car very soon. The car is also even smoother after all new bushings, it's not every day a track car with 800lb front springs and smooth ride are said in the same sentence. Total time in the shop on Sunday was 15.5 hours! Huge thanks to Ryan for helping with all the fab this weekend, it was a brutal one.
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