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PostPosted: May 1, 2016, 5:21 pm 
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Location: Atlanta, GA
Car was finally delivered few days ago and I love it. 2 questions:
1. Can I drive it in rain? I don't see how water wouldn't get in through that intake filter so I'm assuming that's a no. Can I make a cover for the intake that would cover the front, top and sides but leave the rear open for air, or does it need direct air?

2. Bike... I mean car is unbearably loud! I can't drive it on the highway without ear plugs. I want to quiet it down a little bit, even if it means losing some HP. Currently it's dyno'd at 168 whp. Has a power commander. I'm assuming I need to change the exhaust set up but don't know how since the stock GSXR exhaust obviously wouldn't fit on this car.

3. At 100mph it's reeving near red-line. I know it's gearrd low for better torque but can this baby handle a trackday at a high speed track like Road Atlanta or would I need to change the gearing for that? Is it a big job to switch back and forth? I think it was mainly set up for autocross.


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Last edited by duc1098 on May 2, 2016, 10:10 am, edited 1 time in total.

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PostPosted: May 1, 2016, 8:24 pm 
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I don't think driving in the rain is an issue. Parking in the rain for awhile might not be so good. I have the same style filter on my formula car, they are all like that.

It is geared too low for a road race course. You'll like it better on the highway with taller gearing too.

Put a reducer on the muffler output, add a smaller diameter extension and elbow.

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PostPosted: May 2, 2016, 12:50 am 
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I you do decide on a reverse hood scoop to protect that filter from other cars driving through the flooded street ahead of you, you might think about extending it far enough back towards the windshield to take advantage of the high pressure area that builds up there.

To find out where that area is, you can tape a fishing line from about 1" off the bottom of the windshield, all the way to the top front of your existing filter housing. Then scotch tape tufts of dark colored yarn to the fishing line every 3-4". The yarn will fly straight back towards the windshield but when the wind pressure builds up near the windshield, the yarn tufts will start changing directions. That point is the beginning of your high pressure area and is a great place to put an opening to an intake or carb.

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PostPosted: May 2, 2016, 8:32 am 
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You don't have windshield wipers, so the amount of rain driving you can do, will have little effect on the air filter. And why would you want to? :shock: Use a good air filter oil; ITG does not recommend using engine oil, and definitely not K&N filter oil.
The gearing may be a bit short, but if I recall correctly, you have a RX7 rear end, so your options may be very limited.
The exhaust is tough. I'm working on version #3. A lot of the noise is also from the intake, so you may need an even quieter muffler. I installed a Supertrapp this winter, but it is still loud. I am now working on a muffler, that is from an early R6.
I do like your 4-2-1 collector. Someone did their homework: 1 - 4 and 2 - 3 is the best combination.

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PostPosted: May 2, 2016, 10:07 am 
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mgkluft wrote:
You don't have windshield wipers, so the amount of rain driving you can do, will have little effect on the air filter. And why would you want to? :shock: Use a good air filter oil; ITG does not recommend using engine oil, and definitely not K&N filter oil.
The gearing may be a bit short, but if I recall correctly, you have a RX7 rear end, so your options may be very limited.
The exhaust is tough. I'm working on version #3. A lot of the noise is also from the intake, so you may need an even quieter muffler. I installed a Supertrapp this winter, but it is still loud. I am now working on a muffler, that is from an early R6.
I do like your 4-2-1 collector. Someone did their homework: 1 - 4 and 2 - 3 is the best combination.


Thanks for the advice guys.
Martin, yes this is the one with the RX7 rear end. I guess I wont take it to Road Atlanta where I usually hit 140mph in my Camaro. I don't feel comfortable staying in red line for that long on the back straight. But smaller tracks should be fine.

I hope I don't get stuck in rain but weather is very unpredictable here in Atlanta. In case I ever get stuck in rain I'd like to be able to get it to safety. I'm guessing track days in rain wouldn't be a good idea.

I didn't think about the noise from the intake... I guess I'll try quiet down the exhaust first and see what happens.


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PostPosted: May 2, 2016, 10:36 am 
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Quote:
I'm guessing track days in rain wouldn't be a good idea.


Again, rain is not an issue. I've raced my formula car more than once in the rain. The dashboard has 2 switches on it. One is the ignition, the other is the rain light which is a single red tail light. These days formula cars are aero so they do have some protection, but traditionally they had none. Rain doesn't really have much water for the volume of air.

Your problem in this area is you don't have a good air filter. Lot's more dry air than wet air is going into the motor and especially if your on a track there is dust. I don't think there are easy cures for this though, but there might be. You need a good paper filter.

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PostPosted: May 2, 2016, 12:41 pm 
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Nice car!

I'll add this in case you ever do decide you want to take it to a larger track.. I fabbed a Miata diff into my BEC for a time (3.9), and like the RX7, ratios are a bit limited.. I switched it over to a Ford 7.5 with custom axles and never looked back.. A ton of ratios to choose from, and most BEC guys end up somewhere around 3.0, depending on what you want the car to do.. Should you choose, I wouldn't say a 7.5 pumpkin swap is quick, but it's not too hard- you could have a few laying around in different ratios depending on which track you want to go to.. They're pretty cheap too.. I'd think with 168whp your car will tolerate a gear change pretty well 8)


Your BEC will never be quiet (in a good way!), but this might take the edge off- https://enderw88.wordpress.com/2009/11/ ... y-inserts/ ..I run one in mine, and again, not "quiet," but it does in fact take a bit of the raw bark off of the exhaust note..


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PostPosted: May 6, 2016, 3:53 pm 
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More than half of all Locosts run an external air filter. In fact, I think the figure is closer to 75%.


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PostPosted: May 6, 2016, 5:55 pm 
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I examined the car last week, gave him some ideas, and turned him on to a local mechanic since he isn't near me.

It is miata based with the miata rear subframe, control arms, and coilovers with just the diff as RX7 twin turbo.
I think the ratio is the standard 4.30:1. It is all race car and needs to be made tolerable for the street as well as road legal and registered, so first things first!

The air filter has a plastic grid frame. I suggested an insert to keep a heavy down pour from dumping through the top straight into the TBs, but it's not an issue yet.

The tunnel is undersized and extra tight with the long pinion so an electric reverse would be very tight. I gave him links to several reverse boxes by MNR, Quaife, one turbo 400 automatic based, etc.

I'll post the pics I took if it is okay with duc1098?

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PostPosted: May 6, 2016, 6:35 pm 
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Miatav8,MstrASE,A&P,F wrote:
I examined the car last week, gave him some ideas, and turned him on to a local mechanic since he isn't near me.

It is miata based with the miata rear subframe, control arms, and coilovers with just the diff as RX7 twin turbo.
I think the ratio is the standard 4.30:1. It is all race car and needs to be made tolerable for the street as well as road legal and registered, so first things first!

The air filter has a plastic grid frame. I suggested an insert to keep a heavy down pour from dumping through the top straight into the TBs, but it's not an issue yet.

The tunnel is undersized and extra tight with the long pinion so an electric reverse would be very tight. I gave him links to several reverse boxes by MNR, Quaife, one turbo 400 automatic based, etc.

I'll post the pics I took if it is okay with duc1098?


Of course.


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PostPosted: May 6, 2016, 6:55 pm 
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I'll clean them up to post. :cheers:

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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PostPosted: May 6, 2016, 7:05 pm 
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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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PostPosted: May 6, 2016, 7:06 pm 
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Enjoy!


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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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PostPosted: May 6, 2016, 7:34 pm 
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Since you brought up the reverse gear.. How difficult would it be to weld a gear on the drive shaft like Martin did in this video and install an electric motor(or power drill?) over it on the fire wall or below the shaft. It look like there would be enough space.

https://www.youtube.com/watch?v=TdObULcKL94


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PostPosted: May 6, 2016, 9:07 pm 
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It looks to me like there is not enough space due to the shift linkage, but if there is, it would involve custom machining and rebalancing, as well as fabricating a starter mount that allows for precise alignment, and its own wiring system to ensure it could only be operated when the engine is not running. This collectively would take a lot of labor and some special equipment most of us do not have.

I do not believe Martin included any labor in his total cost estimate of $100 and he obviously has the equipment.

Also, if it is not installed precisely, the gear can easily be damaged by the starter and the driveshaft building process would start over with a new gear.

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12


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