I really like the idea of the 20b powerd 3rd gen but i doubt it can still handle as good as a 13b 3rd gen......but wat the hell do i know i drive an mx-3......lol

 

I dont think so, since it weigh's more than the stock 13b rew...maybe if you add weight in certain areas of the car you will be able to get the 50/50 weight distribution but that means you are putting more weight on the car...

 

Does it really make you feel better to have a car thats 50:50 when it's parked?

 

hmmmm.......wtf do u mean by that.....lolz,,,,,I just wanted to know cause i bought a dead 3rd gen and although i like the idea of a 20b 3rd gen....i do autoX on occasion and wondered if a 20b is more suited for the straight line racer.......i likes goin fast on the turns....so maybe i should stick with my original plans and go the 13b route.....newayz thanks for nothin......

 

I think that a modified 20b, single turbo, no air pump, no A/C, no emmisions equipment, etc. would weigh about the same as the stock 13b with the sequential twins and all that unneeded junk under the under. Just a guess though I could be totally wrong.

 

Just FYI But the car is NOT 50/50 from the factory either. It is very close but not exactly 50/50 52/48 i think it is.
Apparently you just read the why would anyone ever do a 20B conversion thread.

The benefits you gain from the 20B far excede the little weight difference that you will get. Hell a V8 in the car keeps the same weight distrabution in the car. Yes it does so don't even go there It has been proven !! Same with the 20B

If you are looking for a auto X car that is the best handling and has the best torque curve,.. Then go with a LS1 in the FD. Great auto-x set-up Ask DamonB..he has driven wingsfans's car.Same with Turbojeff when it was in the NW area of the country.

Plus given the fact that it sounds like you are starting out in the race field. a 50/50 weight distrabution is the least of the worries for you. Learning how to drive is bigger.By that i mean learning throttle control steering control etc.. All the things that everyone "Thinks" they are good at before they get on a track The car is secondary to begin with it is the least determining factor in your runs in the beginnig.

 

ok i have been racing 60 hp go karts for the last 5 years and i guess i am a decent race kart driver but i didn't really ask wat i need to race in autox.....newayz i dont wanna get off topic so lets get some real facts on here!!

 

50/50 is really easy to do. Just stack some sandbags in the hatch...

 

welli just told you that it doesn't screw up the distrabution..and that is is not 50/50 to start with!! what the hell else do you want? and oh geez 5 years of go karts... your ready for F1!!

hwey why not throw your go kart engine in the car!! That will get you to 50/50!!

Do a search for your info that you desire, As your imature attitude is getting you no where. Put out your facts as to why you think the weight will be screwed up. Do you even know what a 13B weighs? or a 20B? do your own research son that is what the search button is for.

 

well, cut the firewall so that you mount it back further. put your battery in the trunk, if you have an optima like me, it weighs A LOT.

not sure if this matters but i think people neglect something i dont know what its called but i call it "swing weight" (i play tennis), which is how far all the weight is from the center of rotation... say you have a pole, having two weights in the middle would allow it to spin much easier, having the weights at the ends would make it much harder to spin.

i would think that having weight towards the ends of the car would make it harder to change direction as the inertia would be greater...?

 

the answer to your question is, Yes.

i scaled a 20b fd. see my post "just scaled a 20b fd" in the 20 b section for the cornerweights.

that having been said, my 13b fd is 48 fr 52 rear. i haven't been beaten at the track (road racing) rear weight is where it's at.

howard coleman

 

.^ What he said for the weights. look for his post on that

here is the link for you to read thru
https://www.rx7club.com/showthread.p...ght=scaled+20B

And that^ is a driving resume..not 5 years of go karting. That is a start but just the beginnig

 

The fact is that weight distribution really doesn't have any bearing on handling. However, changing the weight distribution of a car "designed" to handle a certain way at a certain distribution is another thing. For an example, the Lotus Elise is something like 39/61, however it basically out performs most cars in handling.

The other thing is that the weight distribution shifts as the car accelerates and brakes (which is what diablone was referring to earlier).

The most important factor about swapping in a 20B is money, not really so much what it does to weight distribution. So many people say "I'm getting a 20B put in" until they see how much is cost to do.

 

Mahjik, you're the man, but that is simply not true. Front heavy cars handle like it. They will tend to push in tight corners and be more tail-happy, regardless of what you do with the suspension design.

Also, slightly rear heavy cars will tend to handle "better" because they have better grip under acceleration and also have better weight distribution during braking.

 

For the purpose of this thread, the 20B weight distribution on the FD will make little difference. 45/55 or 55/45 is most likely not going to be noticed a whole lot. Many people have commented already that the V8 swaps (while adding more weight) doesn't affect the handling of the car.

I should have made it clear that I was referring to FD with respect to engine swapping changing the weight distribution, thus having a negative effect on handling.

 

Thus the reason that a "mid-engine" layout (with the engine placed just ahead of the rear axle) is usually considered the optimum configuration for a sports/racing car, but isn't often used in sports cars due to space concerns.

 

Very true, Mahjik. Also, I think it's funny how many people on the forum seem to be concerned about small changes in the car's at-the-limit handling when they've never been to the track....

 

I agree, and yet you don't hear about things such as corner balancing in the same coversations. It's always just weight distribution.

Heck, I wish I could get driving skills where I could be concerned with at-the-limit handling. However, I'll leave that for the pros.

 

That's actually only part of the reason. The polar moment of intertia for the car is also much lower when the bulk of the mass is closer to the center of gravity vs. evenly distributed across the whole chassis.

 

Correctamundo, but that's why I said "thus the reason that", not "that's the reason why"; I was trying to point out that the mid-engine layout is considered optimum, but not specifically due to the weight distribution aspect. Sorry, english skills suck.

 

If you're concerned about weight distribution, that can be fine-tuned via suspension settings (research corner-weighting). With regard to polar moments, you can compensate for that by means of weight reduction in the front.


But as mentioned by rynberg and Mahjik, you'd be better off "fixing the nut behind the wheel" first. For racing purposes, added power can be a liability if the driver (and the rest of the car's setup) is not able to use it properly.

-s-

 

I would love to hear how adjusting the corner weights is going to change the front/rear weight distribution...

Corner weighting is not going to magically remove weight from the front axle and move it to the rear axle.

Would make for a good Polak joke: How do you keep a Polak busy? Put his racecar on scales and tell him to adjust the corner weights until his front/rear weight distribution is 50/50.

I made the joke earlier about adding sandbags. That's the only way to do it other than relocating axles themselves. You physically have to add/remove or move mass around the car; you cannot adjust front/rear distribution with spring settings.

 

DamonB, I'm not a mechanical engineer, so this is not my forte, but I know for sure that my team makes small changes to the weight distribution of our car by adjusting the ride height, which is a suspension setting. If you want the front tires to see less weight, raise the front ride height on both the front-left and front-right (or lower the rears). Ride height adjustments can be done without changing springs, with certain suspensions. If you've got money to buy a 20B, you've got money to buy fully adjustable suspension also.


If front/rear corner weights are a different concept than front/rear weight distribution, please explain it to me, or show me where to find the answer. I mean that with no sarcasm at all, but I don't understand what is wrong with my current perception.

If you're talking about center of mass or center of inertia, then I agree with you, adding mass to the front of the car will move the center of mass forward, and you can't do anything to change that except remove weight in the front or add weight in the rear. But in my understanding, weight, which is the measure of a force (namely mass * gravity), can be affected by changing heights as I described above.

-s-

 

depends where the 20b is positioned

 

Gravity doesn't change with height. Corner weighting is only changing (and minutely at that) how the weight is distributed over the wheels at a standstill. Dynamically (when the car is in motion, accelerating or braking), the weight distribution will basically remain the same; a rear-engine car will always behave better under heavy braking than a front engine car, no matter how far you jack up the front end of a front engine car (under realistic conditions, of course).