Wanna vote on my race car build-up?
 

I'm building a race car for my wife to play with at auto-x and road course events. My mustang is too much to handle and requires a level of finesse with the throttle that I don't think she's got. Plus it really is cheaper to race a race car than a street car.


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It's a Formula Ford chassis (circa 1971). The series uses old pushrod 4cyl Ford engines and a 4 speed transaxle. I was thinking of something a little more interesting. Like maybe a Rotary (2 rotor) or a R6 or R1 engine.

We're picking the power plant and a rear drive transmission and final drive setup. If you guys can't come up with something interesting I'll back down and do the Ford 4 banger pushrod (with a turbo).

my vote would go for the 4cyl turbo

1.3L wankel

bridge port it and put on a turbo


they aren't that expensive and they are crazy light

Actually in a car that light you might want to do a turbo or a bridge port cause doing both might be too much

you can get the 1.3 with a stock turbo aswell

Are you aiming for a certain class or just building what you want? I would stick with a 2.0L Ford. No need to get fancy unless you want to drive it. And in that case, turbo.

How light do you want this to be? And is there a way to find out if I've got an autox here in state? Because I've heard of people in three or four states talking about autox and now I'm interested in it.

i would go with a motorcycle 4 cylnder and a short ratio 6 speed. you saw my indy car thread right? that was a 2001 cbrf4i drivetrain.

There is one just about everywhere now, even in Purto Rico. Where do you live in CO? Your gona be in the Rocky Mountain Division, pick your region.

http://www.scca.com/divisions.aspx?div=rm

it'll have to be either a 4cyl or a rotary. Nothing else is small enough.

what is bridge porting to a rotary? net effect?


I'm going for something that's faster than my stang but with a pantload less grunt. Something you have to keep the rpms up for there to be much tq to the wheels. The motorcycle engine has promise there as well as the wankel. The ford 4 banger actually has a little more bottom end than I'd like (but a 2.0L DOHC Zetec is in the option list). What kind of power you think a 14psi turbo'd and bridge ported 1.3L wankel will slap down?


It'll end up in the same class as an Atom or any of the other tube frame wonders. I'm not so much worried about class restrictions though. We'll take this out for fun runs. If I decide to class race I'll probably do it in a Miata so it's easier to compete.

Looking for 1200lbs or less dry. I'd like to end up with a power:weight ratio a little more aggressive than the ariel atom. Looking for 0-60 in 2-3 seconds and a top speed <130mph.

linky plz. I really like the 15K rpm redline I can have with some of the hotter bike motors and they already use multi disc clutches (and are fuel injected) so it's easy to tinker with them. It'd be mostly a matter of deciding on which bike. I don't want a Hyabusa motor as they're startlingly expensive. I can get an R1 (180bhp) or an R6 (111bhp) for 500-800 bucks.

Colin, I'm sure you've heard of Baby Grand cars right? Or how about Legends cars? Water Cooled motorcycle engines (Yamaha XJR 1300), 6-speed etc. I think, like Pure said the motorcycle engine would be the route to go, trust me, it would more than give you a kick in the pants.

http://www.babygrandracing.com/car.htm

http://www.rotaryengineillustrated.c...e-port-16.html

this explains a bridge port a little


now if you do use a rotary you will probably want one from a second generation rx7 cause the 3rd gen motor is twin turbo makes 280 hp and is very expensive (could be fun)


the 2nd gen motor you want is either the s4 or the s5 the 5 is slightly lighter and makes a little more power than the 4. With a stock turbo the s4 will have 189 and the s5 will have 200 with a bridgeport on either of those you will have between 230 and 240 with about equal torque if you put on an aftermarket turbo you will get more power obviously but I don't know how much it will do for you

these motors can bolt up to a 6 speed tremec t56 if you want aswell


http://www.jdmenginescorp.com/engine...s5-engine-swap

here is a s5 13b T with 5 speed transmission comes with all this for 1,700
they quote it at 205 hp on stock boost my guess is with a bridgport and 14si you can push 300 hp really easy
Block
Turbo
Intercooler
Intake Manifold
Sensors
Exhaust Manifold
Fuel Rail
Injectors
Throttle Body
Alternator
Power Steering Pump
Wiring Harness
ECU
5 Speed RWD Transmission



Need I mention how much easier it is to run an aftermarket turbo on a car that is already set up for a stock turbo

here is the link:

https://mustangboards.com/pictures/3...-indy-car.html

we calculated that the lbs : hp is about 5lbs : 1 hp

Here is almost everything you need to know about rotary porting along with pros cons and NA hp estimates.

http://www.mazdarotary.net/porting.htm


kinda a long read but it has pictures

killer. That was perfect. Now I'z be understandin'. Looks like a decent option.

http://static.howstuffworks.com/gif/...ne-housing.jpg

http://static.howstuffworks.com/gif/...gine-rotor.jpg

Rotary engines are kind of an addiction for me because the are so simple and yet so complex at the same time


you can see where the porting is done from the pictures in the link I gave in the first picture

the "bridge" is there for the corner seal which is the circle with a hole at the top of the apex seal

it looks a little complicated but you can do it with a dremel and stencle of the port size you want

wut motor? the spinning doritio?