i'm sure this isn't the right forum, but it's the only one i play in, but is an n/a 3 rotor less costly than the $20K i see for the normal 3 rotor conversions? maybe i have piston blood in me and i want to bore and stroke :0)

 

You wouldn't have to spend the extra money trying to rig up the turbo system. The long block 20B's usually run around 4k, so figure mounting, ECU (still need a standalone, prolly), and everything else, you may be able to get by for under 10K. There is a 20B forum, here.

 

well most of the time you get the stock turbos for free, cause they come with the motor.

mike

 

The commercially-sold 20B is actually a 20B-REW, which means that it comes stock with twin turbos. It would probably cost you more money to remove the turbos and convert it to an NA than it would to just use it in its stock form. You may be able to find a cheap 20B-REW that has bad turbos but a good block (not much chance of that) which would allow you to come out slightly ahead with an NA conversion. Also note that the stock 20B-REW is rated at about 280hp, and removing the turbos would put you down to about 200hp at the flywheel. Another option is to buy a Mazdaspeed 20B race NA engine, which isn't street legal and costs about 10 times as much as a used 20B-REW, but it is good for about 500hp give or take.

Basically, if money is an issue, then forget about the 20B.

 

does anyone have any info on the PDM racing n/a 20B?

 

and have inquired extensively. quotes for the job range from 4-5k to 8k. The people that seemed to know the most about it were www.revolutionrotary.com
write to me at jeremy@kosman.com and I will forward all the e-mail I interchanged with them and rob golden.

 

But the stock twin-turbos won't fit without modification of the engine bay.

 

I can't see how that would work. Converting a 20B to run without turbos is as easy as pullin the turbos off and fabbing a 3-1 extractor. Neither the clutch or the fuel system would have to be nearly as expensive.
A friend of mine has done this, using a MicroTech to run it. The engine is internally stock. It powers his Mazda 808 wagon (~2000lb), has massive torque from low revs and is scary fast. Ain't that the truth...

 

The 20B itself will not fit without modification to the engine bay.

We have different labor prices and different common performance parts in the US. The custom header would be more expensive than a custom downpipe in the US. The most common entry-level fuel and clutch upgrades for an RX-7 are the ACT street/strip clutch and the Walrbo 255lph fuel pump, which would work for either a stock 20B-REW or a stock 20B with the turbos removed. So basically it comes down to paying a few hundred dollars more to go from about 280hp to about 200hp, which isn't such a great idea in my opinion.

 

There are plenty of other cost considerations too though, like intercoolers and cooling systems. Some also prefer the simplicity of an NA engine (although I'm not one of them...), and an NA 20B would provide similar top-end performance to a mildly worked 13BT, with better bottom-end. Horses for courses.

 

Well, I was referencing a budget installation because that seems to be the concern of the original post. An intercooler is not required for the stock turbo option. I think that either option would require a better radiator, but I'm biased because I don't like the stock FC radiator at all. I will agree that the turbocharged option would get expensive quickly as the owner desires more performance. However, the non-turbo option will get louder as the owner desires more performance.

That's a good point. I think the initial installation cost would be slightly less for a stock 20B-REW, but removing the turbos would keep the operating and repair costs down.