Nath_RX8

Names nathan got a 192bhp rx8
Looking to pull some more power out of it
Been looking at turbo and supercharger kits. Not sure what to go for tho.?
Anyone with any info etc.?

stinksause

iTrader: (5)

greddy is the cheapest and has most support/upgradability/info
supercharger is the reliable to expensive way

I would get a full 3 inch exahust and an intake if you have not already ... by full 3 inch ... I mean proper connections (3 inch) ... NOT factory connection points ... so it has to be custom ... AFAIK there are not aftermarket exhausts made with 3 inch joins

Nath_RX8

Iv got a full 2.5' downpipe back system.
So turbo is the best route then.?

8 Maniac

iTrader: (1)

I'm not sure which is best. There aren't many threads on this topic and no one has really posted extremely detailed examples of what they did for their builds and why. Even if there was information here, they really don't provide an easy way to find what you may be looking for.

I really wish we did have plenty of information already and a way to just search for it with little to no effort at all but that is, sadly, not the case, apparently.

I wish you luck!

stinksause

iTrader: (5)

If you don't mind replacing engines then sure, turbo is better ... if you want to minimize side seal spring wear and weakening while upgrading power, go for a supercharger.

Turbo is cheaper and more available

Supercharger is more expensive and less available

Its easier upgrading a turbo system down the road, but turbo wears your engine significantly more, maybe this is why more people sell turbo systems than supercharger systems.

It's your car, you decide what's better.

8 Maniac

iTrader: (1)

I'm by no means an expert, but why would a supercharger be more reliable? Why would it cause less side seal spring wear? I'm legitimately curious because I haven't heard those specific arguments before. My question is also under the assumption that you are comparing similar power/boost.

alnielsen

iTrader: (4)

I would agree. Boost is boost. Anyway you go, your going to reduce your engine life with forced induction.

bse50

It's cheaper to just upgrade to a 231hp model.

stinksause

iTrader: (5)

http://www.pettitracing.com/wp-conte...lureTheory.pdf

Let's take an s/c and turbo system of equal power

You generate more heat and pressure (in the manifold) in a turbo system because you need to drive the turbine. In a s/c system your exhaust gas is free flowing out. Side seals are known to be the weakness in our engines (there are many threads covering this). When you add even MORE heat from the turbo system, you accelerated this failure.

I am not saying that a s/c will not affect durability, you still introduce more wear, but not as much as the turbo system.

Pretty sure that's factory

bse50

That's marketing, not science.

stinksause

iTrader: (5)

I disagree ... it makes sense

so you are saying a turbo and a s/c of equal power will cause the same wear on an engine

bse50

I doesn't make sense. It's just a general statement that may hold true for just some turbo locations with some types of manifold. Therefore that's marketing, not science.

A turbo will make around 100hp every 7-10hp stolen from the engine, a supercharger makes 100hp for every 30 or more hp needed to spin.
A turbo always makes more sense on a small displacement, high revving engine. With newer technlogies and blade designs turbos can also be defined as "better" in all cases.

stinksause

iTrader: (5)

Your point is true for a PP exhaust rotary with a larger seal crossing the exhaust port than our engine that is plagued with weak side seals; introducing more heat will cook them further.

I agree with you on the parasitic power losses, but since you have less back pressure, I believe you will end up with throwing less heat at the side seals and your engine will last longer.

I guess we can agree to disagree.

Nath, here you go ... there is still a lot of discussion like this on a lot things with respect to the rx8, you will have to choose who you believe and what you do. Unfortunately, we can all agree that F.I is really the only way to get more than 220 whp out of the car.


like the low mount greddy manifold with the tiny t25 flange?

You are saying this will be a smaller issue for say a top mount T4 flange?

I agree, but I think the issue will still be present but it will be larger than that if you had a s/c

8 Maniac

iTrader: (1)

They specifically noted that the issues occurred when a turbo system was pushing more boost than it was designed for, therefore resulting in the additional back pressure.

Unless I'm mistaken, an improved turbo selection would avoid this problem, correct?

Eventually, the supercharger would require an upgraded exhaust too if it was able to flow enough air. Since the turbo becomes a part in the exhaust system, you have to consider that it will hinder exhaust flow based on certain factors. If that article suggests anything, it's that you should consider the appropriate turbocharger based on your goals for tuning and consider the various ways it could affect reliability. I don't think this is a problem that is inherent (to significant levels) for all turbochargers.

I would agree and disagree. They do plug their services, but they don't make any references to an alternative option (their SC) to turbochargers. If they had done that, then I would say it's obviously just marketing.

bse50

My point is true for every form of exhaust port. Forced induction introduces more heat in general, compressing air heats it up. I agree that a cast manifold like that found on the greddy kit may retain more heat in a turbo application and lead to problems... but that's a possibility for just a single turbo kit when used out of its optimal range.

How about a top mount turbo? Completely different scenario.

Back pressure is a myth in general and is nothing in general when compared to the increase in dynamic pressure that any forced induction introduces inside the chambers.

Yeah, all in all we can agree to disagree.

stinksause

iTrader: (5)

mods should retitle this: Turbo and S/C ... Agree to Disagree

TeamRX8

iTrader: (25)

just because you admit to being a n00b doesn't get you off the hook for starting new pointless threads on old well worn out subjects in the wrong forum area, leave it to the usual suspects to jump right on in and make the same old tired arguments too (me included)

bse50

Team... do you think an obese on a rascal with an oversized 48v electric motor holds an advantage against an old man using a common rascal that's fully charged?