DYNO Day Figures :D

[JAP-S2K]

Not sure what you meant by this - what did you mean? So are you saying exhausts need to be 65 or 70mm in order to work well, with or without engine mods? What are the sizes of non-Japanese exhausts? The sizes of good exhausts that generate power are related to their respective abilities to optimise exhaust scavenging, based on desired engine characteristics. Some brands just copy. N/A and F/I usually have different requirements.

What i meant was that most Japanese tuners offer an exhaust which will improve engine response, sound, and still remain legal(not always) and are a bolt on fit and are designed for a standard F20C. These are generally 60 to 65mm. 70mm systems are generally designed for track only use as nearly none are quiet enough to comply with any epa laws, and most do not have a cat option.
Obviously a 70mm system without a cat will flow better than a 60-65mm system with a cat. And it will produce more top end power, but you lose some throughout midrange power. IMO 70mm is useless unless your constantly up it. Sure, exhaust flow generally equals power, but back pressure also plays a part in N/A tuning. I'm not saying the 70mm are shit. I think there not intended for street use.

[tekung89]

tune the car to however its gona be used or dont touch it at all. a car built for everything is pointless

[9large]

What i meant was that most Japanese tuners offer an exhaust which will improve engine response, sound, and still remain legal(not always) and are a bolt on fit and are designed for a standard F20C. These are generally 60 to 65mm. 70mm systems are generally designed for track only use as nearly none are quiet enough to comply with any epa laws, and most do not have a cat option.
Obviously a 70mm system without a cat will flow better than a 60-65mm system with a cat. And it will produce more top end power, but you lose some throughout midrange power. IMO 70mm is useless unless your constantly up it. Sure, exhaust flow generally equals power, but back pressure also plays a part in N/A tuning. I'm not saying the 70mm are shit. I think there not intended for street use.

Well, you've got a few generalisations there, and you've contradicted your previous post - there aren't too many exhausts with 65mm tubing You are correct (in your latest post), that most systems have 60mm piping, but probably not as prevalent as you'd think. Doing some quick research of 86 exhaust systems for the S2000 - of the exhausts with reported sizes - 37 are 60mm, and 23 are 70mm. There are 3 of 63mm size.

Sure, 70mm exhausts tend to be louder than the smaller ones, but this doesn't mean that they were designed for the track, and vice versa. A lot of the manufacturers make exhausts in both 60mm and 70mm tubing intended for either or both street and track use. Note, that these Japanese manufacturers tend to design these exhausts for their largest markets - Japan and North America - where respective local laws usually differ significantly from those in Australia, and may be less strict. A common theme for N/A cars, however, is that single exhausts tend to dyno/produce more power, making them more attractive for race tracks where noise restrictions aren't in place. Sure, we all know that a lot of mods make no or less power to the F20C, but FWIW, after having the intake and exhaust installed a few years ago, I dyno'ed significant gains in power and torque over stock, across the entire rev range - there was no loss in mid-range and big gains past 6K.

But seriously, if you want to make the most power-per-buck, you need to go F/I.

Some of you might find this thread useful from S2Ki, which as usual is a great source of information for our car.

S2Ki Official Exhaust Thread

[Age_S2000]

OFF TOPIC
i need help now

does enyone have a spare LH Head Light washer or know were i can get one other then honda.... i had a tiny accident last night and broke that only.....

PM me please

[vyets]

There are alot of 70mm catbacks with resonators avilable.
Greddy TI-C, J's Racing 70RS, ASM S-Special 70, T1R EM 70.
Both the ASM and the T1R are very very quiet 70mm systems.
Then you got the full blown race ones like the
J's 70RR, Amuse R1000, T1R 70RT which are the full header back systems with no cat and resonator.
And most 70mm exhaust will gain through the whole rev range.

There are alot of company's coming out with the 70mm type exhaust now, obvious reasons why they just gain more power.

But most people are not after power but are after sounds and looks thats why Duals are available and 60mm Duals for the super quiet and looks.

Yeap back pressure does play a part in NA tuning, but that was back in the 1.6L days with our 2.0L a 70mm is fine. Not just for our F20C, but most of the K20 guys love the 70mm they gain heaps.

[9large]

^ x2

[h17am]

:O :O :O at 120kph u have 25hp more :P what quarter mile times u pullin mate i like it

h17am - were did you get the Throttle body and how much approx?

Not a 1/4 mile fan.

Throttle body is a spoon item. It was around $600.

[F20C]

age what happen!?

[F20C]

oh wait wet weather i can only imagine haha :P

[papa_]

OFF TOPIC
i need help now

does enyone have a spare LH Head Light washer or know were i can get one other then honda.... i had a tiny accident last night and broke that only.....

PM me please

im shaving those soon say ill let you know when i take them off

[F20C]

papa, clear your inbox messages lol im trying to send you one back :P

[JAP-S2K]

Well, you've got a few generalisations there, and you've contradicted your previous post - there aren't too many exhausts with 65mm tubing You are correct (in your latest post), that most systems have 60mm piping, but probably not as prevalent as you'd think. Doing some quick research of 86 exhaust systems for the S2000 - of the exhausts with reported sizes - 37 are 60mm, and 23 are 70mm. There are 3 of 63mm size.

Sure, 70mm exhausts tend to be louder than the smaller ones, but this doesn't mean that they were designed for the track, and vice versa. A lot of the manufacturers make exhausts in both 60mm and 70mm tubing intended for either or both street and track use. Note, that these Japanese manufacturers tend to design these exhausts for their largest markets - Japan and North America - where respective local laws usually differ significantly from those in Australia, and may be less strict. A common theme for N/A cars, however, is that single exhausts tend to dyno/produce more power, making them more attractive for race tracks where noise restrictions aren't in place. Sure, we all know that a lot of mods make no or less power to the F20C, but FWIW, after having the intake and exhaust installed a few years ago, I dyno'ed significant gains in power and torque over stock, across the entire rev range - there was no loss in mid-range and big gains past 6K.

But seriously, if you want to make the most power-per-buck, you need to go F/I.

Some of you might find this thread useful from S2Ki, which as usual is a great source of information for our car.

S2Ki Official Exhaust Thread

Yeah, perhaps i didn't make myself clear on exactly which systems i was talking about. And perhaps what i should have said is single only systems. As there are only a few (IMO) that are worthy of getting, sure there's heaps out there. But again IMO I don't bother to mention any of the crap copies coming out of the states or elsewhere. As most performance worthy parts do
come from Japan as most tuners do R&D and a small amount from the States. I personally seen a full J's 70 titanium seen run back to back, factory vs J's, and seriously the gains were far from being impressive to brag about especially for the price.
As for dyno figures, It's difficult to quote as there are always more than 1 aspect that will change figures.
You mentioned a significant gain. What is a significant gain? I might think 5-10hp is lame. Yet you may think it the bee's knee's.
Yeah i agree, you want a significant gain, forced induction is the logical answer, yet so many people are quick to think you get massive gains from installing a CAI and exhaust. Lets be honest, the gains you get from doing cams, head work, quad throttles and possible storker kit, are still nothing to brag about, especially for the money you need to fork out.