The Great RX-7 Rally Car Build!!!
10-13-09, 01:27 AM
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The Great RX-7 Rally Car Build!!!
OK! So after spectating my first rally in 2002, it is now 2009 and I am finally fulfilling my dream of rallying an RX-7!
I bought an awesome RX-7 shell from rx7club member datsun1200 and am converting it into a full-on rally car. I will be updating the progress in this thread -complete with photos!
Basically, to rally a car, I will need to gut it, install a roll cage, race seats, race harnesses, rally computer, rally lights, and a slew of other safety, reliability, and performance mods.
I will also chronolog the costs of this major endeavor for anyone in the future who wants to do the same.
The car: 1984 GSL
As I received it: a completely rust-free GSL with a GSL-SE (13B) drivetrain and suspension. It has a full RacingBeat exhaust system, MSD ignition, electric fan, A/C gone, manual steering, hi-flow fuel pump, and had a Holly 950cfm carb (which I need to replace with a stock Nikki carb).
To run a rotary legally (they were banned for a while) in Group 2 (2WD under 3 liters), I will need completely stock porting and induction.
Planned mods:
Stock intake
Stock carburetor
Roll cage
250lb Springs (to land well after jumps!)
Tokico shocks
4 Hella 125-250Watt rally lights
2 FIA Racing seats
5 point harnesses
Terratrip Rally Co-driver's Computer
Metal skid plating
Rally mud flaps
Fire extinguishing system and safety kit
Rally tires and a shitload of extra wheels
Tow hooks (for when they need to pull me out of a lake or out of a ditch)
Misc other stuff
Here she is!
And, of course, some work beer!
Cost so far:
Car - $1250.
If anyone is interested in the interior parts, let me know, just send a reasonable offer + shipping and it's yours The only thing I am keeping is the Dashboard and heat controls. Everything is in great shape!! Especially the headliner, passenger seat, center console, carpeting, storage bins, shifter boot and surrounding plastic, and glove box.
I bought an awesome RX-7 shell from rx7club member datsun1200 and am converting it into a full-on rally car. I will be updating the progress in this thread -complete with photos!
Basically, to rally a car, I will need to gut it, install a roll cage, race seats, race harnesses, rally computer, rally lights, and a slew of other safety, reliability, and performance mods.
I will also chronolog the costs of this major endeavor for anyone in the future who wants to do the same.
The car: 1984 GSL
As I received it: a completely rust-free GSL with a GSL-SE (13B) drivetrain and suspension. It has a full RacingBeat exhaust system, MSD ignition, electric fan, A/C gone, manual steering, hi-flow fuel pump, and had a Holly 950cfm carb (which I need to replace with a stock Nikki carb).
To run a rotary legally (they were banned for a while) in Group 2 (2WD under 3 liters), I will need completely stock porting and induction.
Planned mods:
Stock intake
Stock carburetor
Roll cage
250lb Springs (to land well after jumps!)
Tokico shocks
4 Hella 125-250Watt rally lights
2 FIA Racing seats
5 point harnesses
Terratrip Rally Co-driver's Computer
Metal skid plating
Rally mud flaps
Fire extinguishing system and safety kit
Rally tires and a shitload of extra wheels
Tow hooks (for when they need to pull me out of a lake or out of a ditch)
Misc other stuff
Here she is!
And, of course, some work beer!
Cost so far:
Car - $1250.
If anyone is interested in the interior parts, let me know, just send a reasonable offer + shipping and it's yours The only thing I am keeping is the Dashboard and heat controls. Everything is in great shape!! Especially the headliner, passenger seat, center console, carpeting, storage bins, shifter boot and surrounding plastic, and glove box.
10-13-09, 02:24 AM
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Gutted:
I am temporarily leaving the driver's seat in so I can drive it around when I get it running (remember, there is no intake on it now).
Next step is install the stock carb stuff (which I don't have yet) and drive it to the race shop to have them fab in a cage.
Inspirational Rally RX-7 photo (someday I will be doing this
):
10-13-09, 09:39 PM
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Totally! I promise to take good care of her!
Right now the engine is sitting without any intake at all. I am in the process of locating a stock 12A intake and Nikki for her.
I have this spacer plate that datsun1200 gave me that should let me bolt up a 12A intake to the 13B block:
I might pick up a carb tomorrow morning at the local rotary shop (he says he has 2). He said they need rebuilds, though.
Right now the engine is sitting without any intake at all. I am in the process of locating a stock 12A intake and Nikki for her.
I have this spacer plate that datsun1200 gave me that should let me bolt up a 12A intake to the 13B block:
I might pick up a carb tomorrow morning at the local rotary shop (he says he has 2). He said they need rebuilds, though.
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10-14-09, 09:26 AM
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Are you going with coilovers?
Will your car be legal with "stock induction" on a 13b?
I've always wanted to try rally, but waited too long. Once you've got a wife and three kids, you start worrying a bit more of dying in a flaming car crash than you otherwise might.
Billy from Respeed has a lot of experience with Rally, so you might want to hit him up for advice. He's always very free with his knowledge and glad to help out...
.
Will your car be legal with "stock induction" on a 13b?
I've always wanted to try rally, but waited too long. Once you've got a wife and three kids, you start worrying a bit more of dying in a flaming car crash than you otherwise might.
Billy from Respeed has a lot of experience with Rally, so you might want to hit him up for advice. He's always very free with his knowledge and glad to help out...
.
10-14-09, 09:35 AM
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Yes I already called and asked the technical director of Rally America if a 12a carb on a 13b is legal. He said ideally, a carb from an RX3 or RX4 13B would be best, but I can use the 12 carb.
9. Group 2 Class: Vehicles must be 2WD, normally aspirated and
derived from models sold globally in minimum quantities of 1000.
a. The engine is unrestricted; with the following exceptions, no
forced induction; must be derived (at least the engine block) from
a product line offered by the manufacturer of the vehicle.
b. Maximum displacement no greater than 3080cc. Vehicles must
meet the following minimum weight (as defined in Article 10.1.H)
dependant and number of valves per cylinder:
Rotary engines are allowed with stock OE porting and induction.
The displacement for a rotary is subject to a multiplier of 1.8 which
shall be applied to the 2 valve weight chart above.
So, a 13B is a product from the manufacturer and it's considered a 2.3L (1.3 x 1.8). Technically, I could put an RX8 motor in there with stock porting, but then they might want it to be mated to stock RX8 intake system 
Originally Posted by Rally America Rulebook
9. Group 2 Class: Vehicles must be 2WD, normally aspirated and
derived from models sold globally in minimum quantities of 1000.
a. The engine is unrestricted; with the following exceptions, no
forced induction; must be derived (at least the engine block) from
a product line offered by the manufacturer of the vehicle.
b. Maximum displacement no greater than 3080cc. Vehicles must
meet the following minimum weight (as defined in Article 10.1.H)
dependant and number of valves per cylinder:
Rotary engines are allowed with stock OE porting and induction.
The displacement for a rotary is subject to a multiplier of 1.8 which
shall be applied to the 2 valve weight chart above.
10-14-09, 10:10 AM
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Now I'm curious why you aren't staying with the fuel injection on your SE motor. Is that not allowed? I don't see any mention saying you can't use it.
10-14-09, 11:45 AM
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hmm yeah the whole stock intake thing is confusing, i mean if you could you SHOULD use the stock RX8 intake, it'll out power the nikki, and run upside down.
there is a rally style car thats been showing up at the track, very weird, compared to the normal road race build.
control arms are stock, but boxed, BIG skid plate... maybe i'll try to grab some pics next time
there is a rally style car thats been showing up at the track, very weird, compared to the normal road race build.
control arms are stock, but boxed, BIG skid plate... maybe i'll try to grab some pics next time
10-14-09, 02:17 PM
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So basically, the reason is that slapping on the carb it's just easier and cheaper
10-14-09, 03:34 PM
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I just picked up this manifold and carburetor from my local RX-7 shop this morning. $80 for the pair. The carb needs to be rebuilt, he says. A rebuild kit is about $30 at Autozone/NAPA/Etc...
10-14-09, 04:42 PM
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Nice, keep us posted.
I vote for an RX-8 swap. If you want to be competitive (and original), you have to push the envelope. Ebay and entire front end for cheap.
I vote for an RX-8 swap. If you want to be competitive (and original), you have to push the envelope. Ebay and entire front end for cheap.
10-14-09, 06:22 PM
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If you go fuel injection you can most likely get most of the components for lower cost through eBay or the classifieds here. A Megasquirt computer is fairly cheap, and will allow you to tweak the engine parameters. You would be able to get more power out of the engine that way. On the other hand carbs are much simpler, and more fun to tinker with. It's a shame you can't use aftermarket induction. Make sure your exhaust is as free flowing as possible so you can net the highest gains from it. What are your plans for suspension? What's allowed?
10-14-09, 06:29 PM
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I would have to use a stock ECU, injectors, manifolds, tubing, wiring, etc.. with fuel injection. Carbs are much simpler
Exhaust is unrestricted, but must have a catalyst. Right now it has a full Racing Beat exhaust.
Suspension is completely unrestricted. I will want VERY stiff springs (250lbs+) and good shocks. I'll stick with stock geometry.
Exhaust is unrestricted, but must have a catalyst. Right now it has a full Racing Beat exhaust.
Suspension is completely unrestricted. I will want VERY stiff springs (250lbs+) and good shocks. I'll stick with stock geometry.
10-14-09, 06:55 PM
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I see, I thought it was an entire SE swap. So, if you don't have all the rest of the stuff to go with the SE motor, then a carb would definitely make sense to me. Too bad you can't use a Sterling on it.
Check with Billy at www.re-speed.com for some ideas on spring rates. 250 is actually a very soft spring. I run 275 ft/150 rear on my daily driver. He'll know exactly what you need to have a great handling car.
Check with Billy at www.re-speed.com for some ideas on spring rates. 250 is actually a very soft spring. I run 275 ft/150 rear on my daily driver. He'll know exactly what you need to have a great handling car.
10-15-09, 09:38 AM
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OK So I might have a little roadblock here. The return fuel line in the car was cut and there is no wiring at all near the carb.
As I understand, the Nikki has a vent that is electronically controlled. Also I think there is a restrictor in the return line that regulates pressure.
This is my first carbureted RX-7. What do I need to do to get this stock carb working without any electrics or return line present?
I called the Rally America tech director and he said I can totally tune and modify the Nikki carb...he said alot of SCCA guys do it for 150+hp on 12a's and that is why we are restricted to the stock carb in rally group 2.
As I understand, the Nikki has a vent that is electronically controlled. Also I think there is a restrictor in the return line that regulates pressure.
This is my first carbureted RX-7. What do I need to do to get this stock carb working without any electrics or return line present?
I called the Rally America tech director and he said I can totally tune and modify the Nikki carb...he said alot of SCCA guys do it for 150+hp on 12a's and that is why we are restricted to the stock carb in rally group 2.
10-15-09, 10:53 AM
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Wait, so you are free to modify the Nikki carb? If that is the case, then you need to look into getting a Sterling carb. Great power!!!
Also, for all of your other carb related questions, this is the site for you: www.sterlingmetalworks.com
Not only does Sterling mod up some killer carbs, but he also put together a library of information on the stock carb at his site. Troubleshooting, rebuilding, modifying, all kinds of info to be had. There is also a small forum where you can ask him about installing the carb under your current conditions: www.sterlingmetalworks.com/bymc
Good luck!
Also, for all of your other carb related questions, this is the site for you: www.sterlingmetalworks.com
Not only does Sterling mod up some killer carbs, but he also put together a library of information on the stock carb at his site. Troubleshooting, rebuilding, modifying, all kinds of info to be had. There is also a small forum where you can ask him about installing the carb under your current conditions: www.sterlingmetalworks.com/bymc
Good luck!
10-15-09, 11:36 AM
#25
Yeah, ship that carb to sterling. Nuff said.
Can you increase choke size? It sounds like yes.
You gonna put an oversized oil cooler in the rear wing? And don't forget to box in the front lower control arms. Heck, any suspension bracket needs bracketing.
Can you increase choke size? It sounds like yes.
You gonna put an oversized oil cooler in the rear wing? And don't forget to box in the front lower control arms. Heck, any suspension bracket needs bracketing.