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Discussion Starter #1
Just by looking at the numbers I think if you plan on going forced induction i.e. Nitrous, Supercharger, or Turbo the Base RSX is a much better platform. It has a lot lower compression ration at 9.8 and also is geared taller. With the lower compression ratio it would probably be able to run 9-11 lbs of boost without rebuilding the block. The only problem may be the ECU but this won't be evident unitl later. If you just plan on putting bolt ons such as Intake, Exhaust, Pulleys and a header (if ever developed) then the Type S is going to be a better candidate. Times in the low 14's or maybe high 13's should be capable if tuned correctly. Just my thoughts.
 
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Discussion Starter #2
ok..can u explain the Compression ratio for me? i know that the higher compression ratio is bad for Tur/Sup/NOS cuz of detonation ..well, wut is detonation? y is higher compression ratio bad? etc etc? <IMG SRC="cwm48.gif" border="0">
 
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Discussion Starter #3
Originally posted by RSXperience:
<STRONG>Just by looking at the numbers I think if you plan on going forced induction i.e. Nitrous, Supercharger, or Turbo the Base RSX is a much better platform. It has a lot lower compression ration at 9.8 and also is geared taller. With the lower compression ratio it would probably be able to run 9-11 lbs of boost without rebuilding the block. The only problem may be the ECU but this won't be evident unitl later. If you just plan on putting bolt ons such as Intake, Exhaust, Pulleys and a header (if ever developed) then the Type S is going to be a better candidate. Times in the low 14's or maybe high 13's should be capable if tuned correctly. Just my thoughts.</STRONG>
Need more info before I can pass judgement. Would like to see specs on the fuel rail/injectors/pump amongst other things. Either way though, there is no way in hell I would boost a car with as high a compression ratio as the Type S. Heck, most of us MR2 guys lower the compression with aftermarket pistons and we have 8.5:1
:eek:
 
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Discussion Starter #4
i bet the RSX can take probably 8lbs. of boost safely (not all the time though).

there's a turboed celica GTS running 7.5 (not all the time though) on stock engine (which has an 11.5 compression ratio on a smaller motor).

it's got 250whp @ 7.5 psi on stock engine.

i would recommend JE for custom pistons. TRD is coming out with an entire set of engine internals that they've developed for chris rado's drag celica (900hp out of the original 1.8l VVTL-i engine but they are not using the VVTL-i mechanism yet) which is what we're all waiting for.

there's great potential for power in these engines considering the light weight of the chassis(s)
 

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Originally posted by YellowMr2:
<STRONG>Need more info before I can pass judgement. Would like to see specs on the fuel rail/injectors/pump amongst other things. Either way though, there is no way in hell I would boost a car with as high a compression ratio as the Type S. Heck, most of us MR2 guys lower the compression with aftermarket pistons and we have 8.5:1
:eek:</STRONG>
how much does replacing the pistons cost?
 
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Discussion Starter #6
Higher compression ratio basically means that the pistons are moving at a faster rate, therefore if you add Forced induction you are going to make the pistons move even faster and this creates even more heat and stress which essentially leads to detonation.
Detonation is what kills your engine.
 

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"Higher compression ratio basically means that the pistons are moving at a faster rate, therefore if you add Forced induction you are going to make the pistons move even faster and this creates even more heat and stress which essentially leads to detonation.
Detonation is what kills your engine."

Hey, I dunno about your example. 11.0.1 is our compression ratio in the RSX-S. That means that a given volume of air is compressed to 1/11th of its origial volume before combustion occures by the spark of the sparkplugs. The higher C.R. (ie compression ratio), the higher the octane requirement. Anything over 12.0.1 is pushing the limits of 93 octane gas due to detonation.

Now on to forced induction. Turbo/Superchargers work by cramming or "forcing" extra air and fuel into the combustion chamber. This exta air and fuel effectivly raises the compression ratio to a higher value than our 11.0.1. If your car is improperly tuned then it will start to detonate and then <IMG SRC="cwm23.gif" border="0"> . Now what detonation is, is a whole other subject that I dont want to get into.
 

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Originally posted by mastap:
<STRONG>"Higher compression ratio basically means that the pistons are moving at a faster rate, therefore if you add Forced induction you are going to make the pistons move even faster and this creates even more heat and stress which essentially leads to detonation.
Detonation is what kills your engine."

Hey, I dunno about your example. 11.0.1 is our compression ratio in the RSX-S. That means that a given volume of air is compressed to 1/11th of its origial volume before combustion occures by the spark of the sparkplugs. The higher C.R. (ie compression ratio), the higher the octane requirement. Anything over 12.0.1 is pushing the limits of 93 octane gas due to detonation.

Now on to forced induction. Turbo/Superchargers work by cramming or "forcing" extra air and fuel into the combustion chamber. This exta air and fuel effectivly raises the compression ratio to a higher value than our 11.0.1. If your car is improperly tuned then it will start to detonate and then <IMG SRC="cwm23.gif" border="0"> . Now what detonation is, is a whole other subject that I dont want to get into.</STRONG>
wouldn't this damage the engine, since you can't really buy fuel that's higher than 93 octane, or is that taken care of by retarding the timing?
 
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Discussion Starter #9
i think some of you are a little mislead to how engines work.. First we'll start off with compression ratio..

Compression ratio is exactly what it sounds like, It is a ratio of the difference when the piston is closest to the head (compressed position) to when its closest to the oil pan (uncompressed). It has nothing to do with the speed at which the engine is rotating.

Let me use a basic example, lets say for instance that we have a small cylinder that can hold say 500 cc's of air (water isnt compressible so its a bad argument). Lets assume this cylinder is like a cup, closed at one end and open at the other. Lets also say we have another slightly smaller cup that can fit into our cylinder and not let any of this air out in the process. Now if we were to push this smaller cup half way into the cylinder, our 500cc's of air would become 250cc's of air at twice the pressure.. You could say this is a compression ratio of 2:1.

Applying this knowledge to engines, modern day japanese engines crank the compression ratio in order to get more force returned for the explosion when the fuel is ignited. The problem is there is a cer
 

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