2bular 4-1 manifold and flexi decat dyno results

Peak figures:

Before: 216whp, 145lb/ft
After: 241whp, 157lb/ft

25whp gain and 12/ft which is fantastic. Essex Autosport did the mapping and were also surprised at the gains. Seems Jim’s new 4-1 design is worth every penny!

now with dyno:

Wow! That is a great increase!

Hmmm where’s Jim’s number :wink:

Damn, might have to upgrade to the new version!
Just the manifold alone will bolt up to one of Jims SDCP?

Neil.

Big improvement - Did yoi have 2bular on before?

What size are the primaries on Jims new 4-1 manifold?

no idea on the primaries. Give Jim a call as I’m sure he’ll tell you the difference between your current and mine. He did smooth out the pipe ends alot from his previous design.

Impressive :sunglasses:

No probs…I was just curious if he’s increase the bore size, or it a complete redesign. Mines already a one off (I think) with 4-1 manifold with 2" primaries into 3" system, but this is probably the old design now.

[quote=C8UER]Wow! That is a great increase!

Hmmm where’s Jim’s number :wink: [/quote]
Don,t you dare disturb him … He,s welding mine up !!!


Great results tho …up. 12%
BRING IT ON :smiley:

Not bad at all.

So to be quite clear, this is a Redesign of the one I fitted about a year or so ago?

If so now I need to upgrade mine, how annoying.

This is a redesign and from what Jim said on the phone its likely to produce very good results.

I thought it was a good gain when I made an extra 18hp and 20lb/ft when we added to the one i have to my setup, but that gain is stagering, it must fel amazing (if you could get the power down in this weather :frowning:

Any chance of some nice piccies please! :sunglasses:

BTW, have you had to fit a MIL light suppressor with your decat? If so, what did you use?

:slight_smile: I sense Pete,s planning an upgrade !!!

piccies of it fitted will be on the way tomorrow. In the meantime:

[quote=aelord]Not bad at all.

So to be quite clear, this is a Redesign of the one I fitted about a year or so ago?

If so now I need to upgrade mine, how annoying. [/quote]

The std header/manifold is a piece of junk, barely fit for the n/a motor. For an SC install, it’s a serious block on power. When I first had an Exige S on the dyno, it showed 204bhp. I was first to design a header/manifold that would improve the exhaust flow out of the head. 12-15% gains were achieved. With various mods - re-flashes, smaller pulleys, intercoolers, etc etc the power outputs have been climbing steadily.
So, it was time to have another look at the 4-1.
Steve’s install was a good opportunity - same car, same dyno, same day, same operator. Most of the variables removed. I was interested in the CHANGE because that would have been down solely to the header/manifold.
Worked very well, very pleased.

[quote=321freeflow][quote=aelord]Not bad at all.

So to be quite clear, this is a Redesign of the one I fitted about a year or so ago?

If so now I need to upgrade mine, how annoying. [/quote]

The std header/manifold is a piece of junk, barely fit for the n/a motor. For an SC install, it’s a serious block on power. When I first had an Exige S on the dyno, it showed 204bhp. I was first to design a header/manifold that would improve the exhaust flow out of the head. 12-15% gains were achieved. With various mods - re-flashes, smaller pulleys, intercoolers, etc etc the power outputs have been climbing steadily.
So, it was time to have another look at the 4-1.
Steve’s install was a good opportunity - same car, same dyno, same day, same operator. Most of the variables removed. I was interested in the CHANGE because that would have been down solely to the header/manifold.
Worked very well, very pleased.

[/quote]

Bulk buy :slight_smile: :slight_smile: :slight_smile: (I am in)

Q.

Having spoken to Jim, I think one of these is going to be on the shopping list for the New Year :smiley:

Oh Exiges…how you cost me money :smiley:

Them results are petty stunning for a Katana which has no intercooler.

Adding a much smaller pulley and charge cooler seems to be only good for another 30bhp! Defiantly getting mine mapped to 330bhp with a smaller pulley in the the new year lol!

[quote=blacktoy]piccies of it fitted will be on the way tomorrow. In the meantime:

[/quote]


Pic of my 2bular (2" primaries) to comapre…

[quote=321freeflow][quote=aelord]Not bad at all.

So to be quite clear, this is a Redesign of the one I fitted about a year or so ago?

If so now I need to upgrade mine, how annoying. [/quote]

The std header/manifold is a piece of junk, barely fit for the n/a motor. For an SC install, it’s a serious block on power. When I first had an Exige S on the dyno, it showed 204bhp. I was first to design a header/manifold that would improve the exhaust flow out of the head. 12-15% gains were achieved. With various mods - re-flashes, smaller pulleys, intercoolers, etc etc the power outputs have been climbing steadily.
So, it was time to have another look at the 4-1.
Steve’s install was a good opportunity - same car, same dyno, same day, same operator. Most of the variables removed. I was interested in the CHANGE because that would have been down solely to the header/manifold.
Worked very well, very pleased.




[/quote]


Hi Jim. I’d be interested to know how much difference you think there is between your original 4-1 (as fitted to my car) and the redesigned new one - I need to work out the cost-benefit calculation!

I agree the OEM one is crap. Big improvement when I stuck your manifiold on.