20b vs 2jz
 

i cant decide between these two. i want power, but i wont it to last for everyday driving. i think that the 20b is just natural for this car being a rotor car, but from what i read from research is that its unreliable. while the 2jz has its problems i think it can take more abuse rather then the rotory.

what would be the avg. price for a 20b, or a 2jz?
i will be installing the swap myself with a few of my motor head buddys.

to even install the 20b into the car, do i have to update everything on the engine as in fuel oil that sort of stuff or is it a direct transfer from stock to new?

thx for the help guys
Josh

i assume u are swapping this into an rx-7, in that case i'd go with the 20b since its a mazda engine in a mazda car...i've never heard of the supra engine in a rex before. the supra motor would take alot of custom fabricating, much more than the 20b. are u even sure it would all fit in your engine bay (2jz)?

yes it has been done befor, i belive there is a few people on there with them, i was looking at rotory extreme, and it seems with some new things they have ill work out. there intercooler kit that wounts up over the radiator, gives are to both of them and a air intake. along with a high flow exhaust system, new fuel system, and some electronics i will be able to tell whats going on b-4 there is any problems with the engine.

anyone know a price for a 20b engine, and were i could get one.

The one good thing about the 2JZ is the transmission.
Build a big power engine, and you don't have to worry about the trans.
Something I can't say about the 20B... :(


-Ted

I am currently in the process of installing a 2JZ-GE which is being rebuilt with a 3mm decompression plate (so i can bolt a BIG turbo onto it) to go into my Hilux surf so i can tow my rx7 to events :)

is there a stronger trans you can get?

so you guys think the 2jz would be best for reliability and over power?

i saw on that online shop for rx-7's there is a gearbox by gready that might be stronger, could solve the problems i guess.

i rly dont kno alot about rotory engines so the piston engine might be better because i have more understanding of its internals.

I hope you have an awful lot of skill and/or money. Either of these swaps will take lots of both.

2jz would be the better engine, much more reilable. Its a tough swap but can be done. The 2jz can hold up to 600 -700 with stock internals and a new headgasket.

3500 to 4000 dollars for a complete 20b engine setup.

3500 to 4000 dollars for a complete 20b engine. that is just the stock motor stuffs.

Why not go with the LS1? It's lighter than both the 20B and the 2JZ and more reliable. They make around 280whp stock and with headers, cam, ported heads (2000 max for these mods) you can have 450whp. You also get torque with the LS1, something that doesn't come standard with any rotary. You can get a LS1 with a 6 speed transmission for 2-4K and there is tons of support for it, not to mention one of the largest performance aftermarkets.

The 2JZ will offset the weight balance more than the LS1. The LS1 is tiny and actually sits lower than the rotary, as far as center of gravity goes. The 2jz is quite long and will put a bit more weight in front of the axle. Plus, you are going to have your whole turbo assembly and probably a FMIC. It will be much heavier and the weight will be higher and more forward.

Why not go with the LS1? It's lighter than both the 20B and the 2JZ and more reliable. They make around 280whp stock and with headers, cam, ported heads (2000 max for these mods) you can have 450whp. You also get torque with the LS1, something that doesn't come standard with any rotary. You can get a LS1 with a 6 speed transmission for 2-4K and there is tons of support for it, not to mention one of the largest performance aftermarkets.

The 2JZ will offset the weight balance more than the LS1. The LS1 is tiny and actually sits lower than the rotary, as far as center of gravity goes. The 2jz is quite long and will put a bit more weight in front of the axle. Plus, you are going to have your whole turbo assembly and probably a FMIC. It will be much heavier and the weight will be higher and more forward.

v8 sits lower then a rotary? are you talking about the shortbloks here, or with all the manifolds and etc. there is no way a v8 can sit lower or not stick out as much as a rotary. it might be close but it wont be the same thing. with the new added torque of the v8 you will have to upgrade the whole entire drivetrain changing the feel of the car, of you want a vette feeling car just buy a vette. if someone is going to argue this point with me dont bother.

a 2jz is 2 times as long as a 13b and the 20b is somwhere between the two. i dont know which geenration rx7 you have but the 20b swap is much more ideal in the FC then the FD. any of these swaps require a lot of money, skill and fabrication.

i have been debating what my next project car is going to be. i am trying to pickup this s5 that has no motor in it. ive been thinking of a 1/2 bridge 13b with like a t78 turbocharger. but that is alot of money seeing i have to have everything balanced and get new stationary gears to do the 9600 rpms that it would do...well for more than 10000 miles anyway. the motor would need about 2000 dollars in mods let alone the rebuild i would have to do. then there is the turbo which would cost me 1500 or more. would have to make a manifold. and have one crazy igntion setup. granted it would be insanely fast...

then there is the 20b. honestly. for 4000 bucks i would drive the car in stock motor forum. the mounts i would just get premade. a FMIC i could do myself for cheap. the only worry is redoing the suspension and making it all happy again. i would most likely add the 6 extra inches up front. damn decision making capabilities!!! the 20b would be damn sweet but what would i do when i need simple crap like gaskets? hmmm....i could get a 13b-RE and work from there on the first idea above....

any thoughts? i need to start off in one direction or the other.

a 20b setup even in teh stock forum is not a cost effective option i am not even talking about the power that it produces stock which is pretty much teh same as the FD> its is much cheaper to do 13b then even thinking of goign 20b with a stock setup.

Search google for the Supra7 by SP Engineering

I want to do an LS1 conversion, but I've heard bad things about Granny and their kits. Anyone have anymore info?

this thread is stupid I really dobt this guy has the time or money to do this for a daily driver. BUY A KIA if you want a daily that you can depend on.

im a high school student, i have time. i dont have alot of money, but i dont plan on doing all this at once. i know alot of ppl that have been working on cars for there life living, ive got guys who know how to wire a car in and out. i could have my own shop with the people i kno.

but anyways this isent ganna be a daily car, its ganna be my weekend car. i dont think it will ever see rain.

but yes, alot of work no matter how meany people i know, and money for that part. im almost thinking of going with a diffrent car. the FD (what i might be getting) looks geat, but all the stuff to get it even better makes it seem like its not worth it. but you guys do talk about it being a money pit lol.

thx for helping me guys.

Get a 240 and have fun with that.

Where are you getting this idea
 

I seriously doubt that Mazda would waste all the engineering to develop a 3 rotor then add turbos to it and have the same power as a 13btt. Getting reliable figures on 20B's in stock form is difficult due to the japanese horsepower gentleman's aggrement (which was just recently lifted...) Also if you find someone that dyno's a 20B and they come up with less than 300, then something is wrong. Just my 2c.

Besides, if you're gonna do something like this keep it in the family. Of the 3 options the 20B would be the lightest no matter what anyone says. If you want to be radically different then go 2JZ

The 20b eunos cosmo had the same hp output as the last production fd. 280hp. The only difference is the torque the 20b puts out.

-Destin

You must not have looked at any 20b torque curves.

-Destin

20B Hp
 

Now is that dynoed power figures or just what Mazda says?

Japanese manufacturers stated hp figures at a max around 280 horsepower, whether that is what they had or not. The supra was stated to have 280 when in fact was over 310, and the Skyline though rated at 276 also made more. Manufacturers made more power, but for whatever reason agreed not to let it be stated over that figure. An antiquated aggreement that has recently been dropped...

Actually that 280 is underrated. Stock 20b's made more than that. I talked to a guy from Aus who said that they make around 320 stock.