Im looking to have a motor built by buschur for my car. Its either gonna be the regular 2.3 they offer, or the 2.3rpm motor. My question is, besides the rpm motor being able to rev higher, are there any other differences? Is one "stronger" then the other? Or are they both completely equal (not in a internal parts sense)?

They motor will be paired to a hta86 turbo and used 95% of the time on the street, maybe hit the drag strip once or twice a year. Its not a daily driver. And it will be using pump gas (93 octane), but i do plan on doing e85 in the future

I dont want to spend the extra 1,000 bucks for the extra RPMs if its really not something im gonna use. I could put that money into something else for the car

 

Send Dave an email asking him. I'm sure he could tell you more.

 

I was wondering the same thing

 

I thought the only difference was the Manley crank....but ask Dave to be sure.

 

Buschur built my engine 2 weeks ago and I went with BR2.3stg3 and from what Nick @ Buschurs told me is that BR2.3rpm the only difference is lightweight crank, otherwise they're the same but the price for the crank is around $1300 extra.

Nick said the safe RPM for BR2.3stg3 not 'rpm' is 8500, if you want spin higher than that, he suggested going 'rpm'. I think 8500rpm is plenty for me, especially that 2.3 made the car wake up at even lower RPM.

 

Where exactly is the redline for the RPM motor?

On buschurs site, it says that its not recommended to goto 9500+,but they done it.... Is a hta86 even making power over 8500 on a stroker? Unless your drag racing, i dont see why you need to goto 9500+

 

Where does a 2.3l spool a hta86 at anyway?

 

I'm not sure, but extra $1000 just to have 1000rpm more where most of the turbo's are running out of breath beyond 8500 didn't make much sense and 8500 is not too shabby either, for a 3k build, I had to spent $9500 for the STI engine to be able to get up to 8500rpm safe w/ GT35R.

 

Exactly, no need for the RPM version unless you are going to revving till 9k+. But I don't think an hta86 on a 2.3 motor is going to make power after 8k or so.
Unless you plan to go much bigger later on....

 

There are other benefits to the lighter crank than just a higher rev range. Reduced rotational mass means less parasitic loss as well as reduced stress on bearings. If It's not beyond what you're willing to spend, why not get the better motor? Better to have it and not need It, than need it and not have it.

 

^thats very true. When it comes down to doing a full motor build anyway, whats 1,000 bucks? Your already spending about $9,000. Might as well spend the extra now so years later when your goals change or a new turbo comes out, you can handle it without getting a new motor built

 

Thats a good point

 

Yeah, there might not be a need for it but if you can afford it why not...you might want it down the road....

 

I went with the rpm for multiple reasons. Rpm, lower rotational mass, more versatility, and resale value. I think this motor I think will appeal to part time drag racers as well as the road race/autocrossers. This motor seemed like the best of both worlds to me. A 2.4l LR would be my next pic but didn't want to do the head machine work and thinner cylinder walls.

 

I find the 2.3RPM to be an ideal candidate for someone running a larger, laggier turbo. Not only does the 2.3L help the turbo spool sooner, it also lets you have a VERY broad powerband (Dave's favorite feature with any build). As mentioned, a small frame turbo would have trouble flowing to 9500rpm on a 2.3L as it is. Depending on how small the turbo is, you may find that it suffers from compressor surge too easily as well.

It all depends on the desired powerband combined with turbo choice IMO. I agree with getting the RPM version for less rotating mass and bearing load.

-Jamie