Completely stripped out/gutted Mazda2 weight?

[flatlander937]

Out of curiosity, I imagine several years from now a Mazda2 could be a potentially viable car to build for the SCCA E-Prepared class.

Here's a basic idea of the class:

http://www.solomatters.com/shopmanual-chapter_7_e-prepared

In a nut shell:

Gut it completely, sounds like you can completely remove the doors and put fabricated panels in their place(ours being 4 door cars I think a good amount of weight can be removed here?)

Removed windows and everything, probably plexiglass or speed glass windshield for convenience. Rear hatch fabricated or replaced with CF(there is someone that makes one for the 2), CF or thin sheet aluminum hood

Engine built up naturally aspirated, high compression, race gas, ported with a pair of wild cams, completely balanced, knife-edged crank, lightweight rods/pistons, etc etc.

Min weight would be 1500lbs since we have a 1.5l engine. There is an add-on to that rule that says you must run a 7" wide wheel, though you can run a 7-10" wide wheel for a 75lb weight penalty... so 1575lbs if you run a 7.5-10" wide wheel. No idea as to what would truly be fastest. (Weights without driver)

Limited slip diff necessary. Slicks of course. Because racecar.

You can also completely lose the dash and everything on the interior. It honestly might make sense to lose the power steering pump/lines/hoses and loop the power steering ports on the rack into each other(like the Miata guys do) since the car will be so light. Lose the headlights and tail lights in lieu of some thin fabricated plates(or just stick the factory lense only in place for aesthetics), etc. There are a lot of places you could lose weight if you look for it.


It would be a relatively inexpensive way to end up with a really fast car for autocross or E-production road racing(well, maybe except for the engine). A local guy has a G-prepared CRX and is consistently one of the top 3 raw times and top 3 PAX times of the day at every event.


Maybe Corksport can chime in with how much their stripped out B-spec car weighs for reference?


Just my random thought of the day.(hi)

 

[extremez31]

I think you could get the car down to 1,400 LBS but you'll really have to get creative. If you wanted to compete in EP on a national level you'll need the car down to the minimum weight with the driver and at least twice the power it currently has. I think it'll be cool as hell. I think our hoods weigh less than CF versions. I actually had a CF hood I bought for $100 and sold for $350.00 It was not all that light. Rear hatch with thin sheet plastic, 4 door skins, gut the interior, remove AC, power steering. My car weighs 2158 with 2 race seats and 3 fuel bars its realistic to see 850 LBS removed if its a 1 seater with no cage or fire system.

Mazda2 b-spec is 1900 lbs I think with the driver. Buy they need to run cages, fire system, data logging crap

 

[zps2004]

I would think that a b-spec car would be close to stock weight. They don't really remove that much weight compared to how much the cage is going to weigh.

 

[extremez31]

I stand corrected, 2300 is the published race weight with driver.

 

[CorkSport]

We are at 2350lbs right now with the driver but I have a 45lb steel plate bolted to the floor board to get me there. The power steering unit is an electric unit inside the cabin so there are no lines to loop on the rack.

-Derrick

 

[flatlander937]

We are at 2350lbs right now with the driver but I have a 45lb steel plate bolted to the floor board to get me there. The power steering unit is an electric unit inside the cabin so there are no lines to loop on the rack.

-Derrick

Ah that's right, I was thinking of the hydroelectric setup on my Mazda3.

A big question is how well the heads flow and how much they can be improved(plus custom cams of course). 130hp is doable with older Honda 1.5l D15 motors according to a guy I autocross with, and its a SOHC head. I imagine 150hp is doable on race gas, though 180+ would be needed to be competitive.

And if the engine can't reach those numbers, maybe offset grinding the crank journals to destroke the engine so more weight can be removed. If the heads flow enough, building the bottom end to spin 10k rpms might do it.

 

[jasyatz]

Ah that's right, I was thinking of the hydroelectric setup on my Mazda3.

A big question is how well the heads flow and how much they can be improved(plus custom cams of course). 130hp is doable with older Honda 1.5l D15 motors according to a guy I autocross with, and its a SOHC head. I imagine 150hp is doable on race gas, though 180+ would be needed to be competitive.

And if the engine can't reach those numbers, maybe offset grinding the crank journals to destroke the engine so more weight can be removed. If the heads flow enough, building the bottom end to spin 10k rpms might do it.

My 90 Civic DX made 108 at the wheels with a stock(ish) out of the box .020 over rebuild kit and .010 shaved off the head.. And that had that DPFI setup (only 2 injectors) not a MPFI (4 injectors) like we have.

My SI was making upwards of 115 at the wheels right before it blew up with 230k on it..All I did to that was a head gasket and shaved the head. The rings were hammered when I bought it with 180k.

 

[jasyatz]

I think you could get the car down to 1,400 LBS but you'll really have to get creative. If you wanted to compete in EP on a national level you'll need the car down to the minimum weight with the driver and at least twice the power it currently has. I think it'll be cool as hell. I think our hoods weigh less than CF versions. I actually had a CF hood I bought for $100 and sold for $350.00 It was not all that light. Rear hatch with thin sheet plastic, 4 door skins, gut the interior, remove AC, power steering. My car weighs 2087 with 2 race seats and 1 fuel light flashing its realistic to see 700 LBS removed if its a 1 seater with no cage or fire system.

Mazda2 b-spec is 1900 lbs I think with the driver. Buy they need to run cages, fire system, data logging crap

Lexan for glass, remove entire dash except for binnacle and remove every wire in the car that doesn't make the engine run. All the lights can come out as with the bumper reinforcement bars and foams, headliner, run 13"wheels with crazy offsets, fiberglass fenders, 2 gallon fuel cell,... yeah 1400-1500lbs for sure. But it would still get killed in EP/DP. but would be a neat project.

 

[zps2004]

13" wheels won't fit over the stock brakes. Well at least I have yet to find a set that will.

A car that light would be fun on track though.

 

[extremez31]

I think a 14 would be the ideal size for the car, especially now that the rev limiter can be raised. 14x9 with hoosers. it'll grip for days. You could build it to be a one lap car or time attack. I imagine in order to be competitive you'll need at least 200 HP. in solo2 and time trials. 250 ish for one lap.

 

[zps2004]

You can only get a 225 in a 14" though. For autocrossing it would be better probably to have the extra grip from the 275 15" and not have the gearing advantage. You won't need it since you will have the power to spin the tires at will anyway.

 

[ULLLOSE]

13" wheels won't fit over the stock brakes. Well at least I have yet to find a set that will.

A car that light would be fun on track though.

Try Jongbloed Racing Wheels. They made a 13x7 for us a few years back that cleared the Yaris brakes (10", the Mazda 2 spec in the GCR is 10.1", but the caliper design is the real factor). The SEB really needs to move these B segment cars to GP, they have zero chance in EP.

8lbs 5oz.

 

[jasyatz]

^^^^^^^

That's them! 13x7... Keiser makes a set also.

 

[jasyatz]

I think a 14 would be the ideal size for the car, especially now that the rev limiter can be raised. 14x9 with hoosers. it'll grip for days. You could build it to be a one lap car or time attack. I imagine in order to be competitive you'll need at least 200 HP. in solo2 and time trials. 250 ish for one lap.

What you really want is a 20x8x13 Hoosier R25 whence up to temperature makes a DOT Hoosier feel like the stock Bridgestones.. Yhes things stick so good, when you come off the course, you have to immediately jack up the car and clean them, or the stones that you picked up in grid will (semi) permanently attach themselves to the rubber..

I'm fairly(almost certain) that's what the EP/DP/GP guys are all running...Full slicks.

 

[CorkSport]

Try Jongbloed Racing Wheels. They made a 13x7 for us a few years back that cleared the Yaris brakes (10", the Mazda 2 spec in the GCR is 10.1", but the caliper design is the real factor). The SEB really needs to move these B segment cars to GP, they have zero chance in EP.

8lbs 5oz.

Are you running RPF1 now?

-Derrick

 

[ULLLOSE]

Are you running RPF1 now?

-Derrick

Yes, 15". When the radial slicks came out and we switched from the bias tires we struggled to keep the tires happy, we were cooking the fronts. That same year we had the Bestwick car (which was built around the 15" Hoosier radial), and any time I ran the two back to back I was quicker and more consistent in his car, so we changed my car over as well. While I would like the lower CG and weight of the 13" package, the tire was just to small to manage the heat - while both the 13" and 15" are a "215mm" wide tire, there is nearly an 1" difference in width between the two. The 15" also came in more than one compound, which makes it a lot more flexible.