My S1 has according to Craig at CMC got the standard OEM manifold. Receipts i have show its been fitted with a Janspeed exhaust at some point from the cat back. Think it also may have the standard cat.
It has the PTP 140 kit fitted including the 52mm throttle body and a pipercross induction kit.
What power benefit (If any) do you guys think id get if i changed the manifold and cat for something a bit better?
Manifold Replacement
Re: Manifold Replacement
At the 140hp point Scott changing manifolds, CATS, etc are a very poor return in value for money terms for the small hp return you may get. The standard CAT is heavy and a little restrictive and I used to use a straight through pipe, but that was with 180hp and is a pain for MOT's. A sport CAT would give a slight improvement but at too much expense.
Likewise you only need a freerer breathing larger diameter manifold when you start modifying the head and fitting T/B's and an Emerald ECU. Rule of thumb is that you need a 15 to 20hp increase between upgrades to notice an appreciable difference.
tut
Likewise you only need a freerer breathing larger diameter manifold when you start modifying the head and fitting T/B's and an Emerald ECU. Rule of thumb is that you need a 15 to 20hp increase between upgrades to notice an appreciable difference.
tut
Re: Manifold Replacement
Peak, probably not a lot without remapping, but you'd likely gain some midrange torque that'll make it feel faster than a few BHP at the top end would anyway.
2010 Honda VFR1200F
1990 Honda VFR400 NC30
2000 Honda VTR1000 SP1
2000 Kawasaki ZX-7R
1990 Honda VFR400 NC30
2000 Honda VTR1000 SP1
2000 Kawasaki ZX-7R
Re: Manifold Replacement
So probably without other upgrades not worth it.
I would like to go K20 at some point but the costs of building rather than selling and buying a pre-converted car seem to be a bit of a false economy.
I would like to go K20 at some point but the costs of building rather than selling and buying a pre-converted car seem to be a bit of a false economy.
- mwmackenzie
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Re: Manifold Replacement
If you're going for a 4-2-1 manifold you need the small diameter piper one, the lager diameter one is said to rob torque if under 160bhp I believe, I could be wrong but that definitely rings a bell!
Last edited by mwmackenzie on Wed Jan 11, 2017 4:54 pm, edited 1 time in total.
Mark MacKenzie
BMW Z4 3.0si, [R14 MMK] To be Ring ready soon
Fancy Ass Merc thingy S [R4 MMK] 85% MacKenzie'd Family Spec
BMW Z4 3.0si, [R14 MMK] To be Ring ready soon
Fancy Ass Merc thingy S [R4 MMK] 85% MacKenzie'd Family Spec
Re: Manifold Replacement
effectively, you are correct (based on what's currently for sale out there).mwmackenzie wrote:If you're going for a 4-2-1 manifold you need the small diameter piper one, the lager diameter one is said to rod torque if under 160bhp I believe, I could be wrong but that definitely rings a bell!
sub ~190Hp, the smaller bore 4-2-1's are better suited (and by smaller I'm talking 5/8" primaries over 3/4", both are significantly larger than the OEM item)
Re: Manifold Replacement
My understanding is that the S2 K series manifold and down pipe provide a small but notable breathing improvement over the S1. Nice and cheap upgrade and they come up second hand quite regularly. There was one on SELOC last week. :thumbs up