Mazda RX7 Convertible with Motor V8

[islero]

Why the hell would anyone want to put a V8 in an Rx-7? They are all about the rotary engines.

[Egg Nog]

Why the hell would anyone want to put a V8 in an Rx-7? They are all about the rotary engines.

Christ, how many times does it need to be said?

More power, more torque, and better efficiency

I'd also like to add that they are generally much more reliable and less expensive to maintain.

About half a year ago I was thinking about buying an RX-7 FC Turbo II that had a 350 Chev in it (from an IROC Camaro). The owner nearly sold it 4 years earlier because he drove it fairly hard and the rotary kept having issues. Instead of selling it, he did the V8 swap. Over the next 4 years of commuting in it daily, he had no engine problems at all, loads more power, and gobs of added torque (especially low-end). He also got noticeably better fuel economy.

[Spastik_Roach]

Wolf, theres a particular magazine in NZ called Performance Car, its a rice mag, but it also has alot of good cars in it.

Obviously a V8 swap is a godo choice into a RX7, however, I think it robs it of its uniqueness. I would, personally, put a twin turbo'd hi output Renesis into one.

[Egg Nog]

Wolf, theres a particular magazine in NZ called Performance Car, its a rice mag, but it also has alot of good cars in it.

Obviously a V8 swap is a godo choice into a RX7, however, I think it robs it of its uniqueness. I would, personally, put a twin turbo'd hi output Renesis into one.

I appreciate your creativity, but in all fairness, that would probably cost more than four times what a built 350 Chev would. Cost is a huge factor when it comes to highly customizing cars. Most people do V8 swaps because the low engine costs actually make it quite effective as far as advantages-per-dollar go. I could put a built-up 3.0 Porsche 968 Engine into my 944, but I'm sure that it would be at least double the cost of swapping in a Corvette LT1 to get the same amount of power.

P.S. - I realize that despite your maturity, your age still prevents you from seeing money issues in the truest light. Just kidding buddy...

[RJ 21]

Whoever said the RX-8 is a updated RX-7 is wrong. Mazda plans to build an RX-7 by 2007 and why would the 'updated' RX-7 be a four door sport-sedan? The true rx-7 is a sport roadster and will remain so. RX-8 is not the new RX-7. Just to clarify things up.

[Spastik_Roach]

Yeah my post was really a sort of Money-no-problem sorta post

[danno]

No, not really. RX-7s are among the best handling cars for the money in the world. Excellent suspension and weight balance. It's a shame that (especially in the 2nd gen) the gas milage was so bad, and there was little torque to be found anywhere in the rev range. The added weight of the Chevy 350 is not actually very much, and where it's located in that car, won't make much of a difference at all.

Actually, never mind, you're right. Someone should've told the talented mechanic who built this that more power, more torque, and better efficiency is a "waste of an RX-7".

wouldnt a V8 affect the weight balance just slightly?

[Egg Nog]

wouldnt a V8 affect the weight balance just slightly?

Most of the V8s swapped into RX-7s are aluminum Chevy 350s, at around 160kg (some are a little more, some a little less). The rotary in the RX-7 Turbo II weighed around 180kg. The rotary sat slightly farther back though, so it works out pretty even.

[Bionic316]

Swapping a V8 into the RX-7 is one of the best all around performance improvements you can do. When you use a light weight V8 motor such as an aluminum chevy LS series or a ford 5.0 fuel injected with aluminum heads you get greatly improved performane and no weight gain, if the proper parts are used you can actually make the car lighter than it orignal came from the factory. Plus you get much better reliability and greatly improved fuel mileage when fuel injected V8 motors are used. I think the with a properly set up v8 and some slight suspenion tuning it basically turns the Rx-7 into a high performace super car, amazing acceleration, great handling, and awesome looks. But I guess that's just my oppinion?

[LeonOfTheDead]

Swapping a V8 into the RX-7 is one of the best all around performance improvements you can do. When you use a light weight V8 motor such as an aluminum chevy LS series or a ford 5.0 fuel injected with aluminum heads you get greatly improved performane and no weight gain, if the proper parts are used you can actually make the car lighter than it orignal came from the factory. Plus you get much better reliability and greatly improved fuel mileage when fuel injected V8 motors are used. I think the with a properly set up v8 and some slight suspenion tuning it basically turns the Rx-7 into a high performace super car, amazing acceleration, great handling, and awesome looks. But I guess that's just my oppinion?

your opinion could be right. I don't now the figures about the weight of American V8s or of the rotary of the old RX-7 as this is. but I would think the rotary is lighter, because it's very small compared to the V8. surely the rotary isn't very recommended for high mileage, but AFAIK even American V8s aren't very easy on the gas. consider I'm from EU, here 20km/l (or almost 120miles per gallon) is a good mileage .
sure the reliability is easily going to be improved with the change.
don't know about the overall balance of the car and so its handling capabilities, it depends on the considerations of above. My opinion is to stick with the standard engine.

and welcome on UCP

[Ferrer]

20km/l (or almost 120miles per gallon)

I think you are a bit off with your conversions...

120mpg is about 1,95l/100km. You meant 47mpg (which is 5l/100km).

[clutch-monkey]

your opinion could be right. I don't now the figures about the weight of American V8s or of the rotary of the old RX-7 as this is. but I would think the rotary is lighter, because it's very small compared to the V8. surely the rotary isn't very recommended for high mileage, but AFAIK even American V8s aren't very easy on the gas. consider I'm from EU, here 20km/l (or almost 120miles per gallon) is a good mileage .
sure the reliability is easily going to be improved with the change.
don't know about the overall balance of the car and so its handling capabilities, it depends on the considerations of above. My opinion is to stick with the standard engine.

and welcome on UCP

an LSx series engine in an RX-7 wouldn't be any worse than many other sportscars, considering they get pretty good fuel economy in a corvette for example.
but if i was buying an RX-7, it'd be for the rotary anyway..?

[LeonOfTheDead]

I think you are a bit off with your conversions...

120mpg is about 1,95l/100km. You meant 47mpg (which is 5l/100km).

damn, yeah, that's what happens when you post numbers while studying numbers