suggested 5SFE extractor dimentions

[Sam_Q]

Hi guys, it looks like I might be making a nice set of pipes for someone soon with a FWD 5SFE. Now seeing I dont know when the exhaust valve closes or the size of the exhaust seat I am a bit in the dark as to that dimensions I should be using. It will be a 4-2-1 set and very likely have 800 to 900mm long primaries with half of that for the secondaries. I would like the primary resonance to happen at about 5000RPM.

However what about the primary, secondary and main system pipe diameter? I was thinking that a 2.25" system might be the best bet?

[TERRA Operative]

This info might be useful....

http://homepage.ntlworld.com/richard...k/15L_4_CY.pdf

intake: 7.2mm lift, open at 2 BTDC, close at 42 ABDC which is 224 degree duration - 110 centreline
exhaust: 7.0mm lift, open at 38 BTDC, close at 2 ABDC, which is 220 duration - 108 centreline

Displacement (cc): 1497
Bore (mm): 74
Stroke (mm): 77.4
Compression Ratio: 9.4:1
Vavles per Cylinder: 4
Cylinder Intake Port Dia (mm): 24.4
Cylinder Exhaust Port Dia (mm): 21

[TERRA Operative]

Add to the above,

I would be looking at a total length of about 1000mm, with an internal diameter of just under 30mm, a collector length of around 310mm which chokes down to about 45mm before expanding back to your chosen exhaust size.

This is for a 4-1 system though.

Here's some more good info on 4-2-1 systems.

http://www.team-integra.net/sections...p?ArticleID=50

[Sam_Q]

thats good and all and thanks for the trouble of posting the info but a 5S engine is a 2.2L?

edit: ah your thinking 5EFE engine

[TERRA Operative]

Ah, I misread.......


Hangon..

[TERRA Operative]

Here you go.

I don't have cam specs, but here is a rough guide on the piping to get you started:

Pipe ID - 33mm
Pipe length - 1000mm
Collector choke - 50mm
Collector length - 350mm

[Sam_Q]

ok thanks, I may only be able to fit 800mm primaries though, how did you work out collector length?

[TERRA Operative]

Shorter primaries will mean a higher RPM tuning point. 800mm will mean an RPM of about 6800.

Due to the 4 cyl 180deg firing cycle, the collector outlet only needs to be about 20% larger than the primary pipes. Rule of thumb is generally two pipe sizes.
A longer collector will make more torque, while a shorter collector will make less torque but more top-end power. Although, with full exhaust system, the length of the collector is not so critical.
That number for collector length is just what the computer spat out.......

To get a good length for the collector, when you put the collector on, make it nice and long (maybe leave the cat out and make the collector all the way to the exhaust or something) and spray a stripe of paint along its length. After several runs you will see a spot where the paint isn't getting burnt off. Use this to determine where to cut the collector to length.

[Sam_Q]

yeah 6800 is pretty much useless however I just cant see enough room for 4 pipes going under the engine longer than that, I will try and curve them up as much as I can but I am not expecting a whole lot.

so 1.5" pipe seems to be the closest (34.9mm) for the primaries and for the secondaries is that 20% of the diameter or cross sectional area?

also I thought the best point for the collector was the hot spot?

[TERRA Operative]

4-2-1 design is a bit more try-as-you-go on the dyno.. You'll have to do some reading up about it to get it spot on. I mainly stuff around with 4-1 gear.
You can't go under the engine and make the final merge around the firewall?

The 20% is in cross sectional area. I assume that it will hold true for the secondaries as it does for the collector.

Sorry, you're correct re. the paint, change my 'isn't' to 'is'.... , maybe leave it a little longer (an inch or so) to improve low down torque a bit. You can always cut it shorter, it's a bit harder to cut it longer....

[Sam_Q]

one last question, what program did you use to work this out?

[TERRA Operative]

I just went to headerdesign.com, it's pretty simple as a lot of the other engine specs are unknown..

[Sam_Q]

ok I will take it form here, thanks again