4-2-1 vs 4-1 manifold with Pics

[Snowface]

I'm looking to replace my 1.4sr exhaust manifold and middle box.

Which is better out of these:
Janspeed 4-2-1 Manifold - ?155
http://www.larkspeed.com/intricart/product/image1/1001463.jpg

Or

Sportex 4-1 Manifold - ?99
http://www.tuning.co.uk/vauxshop/media/SPV150100.jpg

Or FFwd do a 4-2-1 looking similar to the janspeed for ?99

any other reccomendations?
thanks.

[m.d.]

maybe its just a pic from a different manifold but the top one is for a 16v, may be worth checking if they acctually do one for your engine first,

the 4 to 1 is better for torque and the 4 2 1 for high reving apparently

[Jim]

Aren't 4-1 manifolds more for race spec engines?

Jim

[scott.parker]

the 4 to 1 is better for torque and the 4 2 1 for high reving apparently

So if you have a highly tuned up valver your better running it on the 4 2 1 set up and would be good for close gears and drag racing?

But if you have a slightly tuned valver engine and want more power and torque etc your better to go for the 4 into 1 set up,is that what your saying mate?

Juast asking btw.

scott

[johnny27]

i always heard that the 4-2-1 is for torque and the 4-1 for reving or bhp. Cause you hear people saying that on a rolling road before and after fitting a 4-1 they lose a little torque but gain a little bhp.

[johnny27]

also i think the 1.4 has more or less the amount of BHP in comparrison (sp wish i had'nt left school early:) with the torque lb/ft. In which case i think most people prefere to have the 4-1 for a quicker response on reving up the engine and, when i put my 4-1 on my t40 engine as soon as you push the throttle out of gear the engine almost sounds like a motorbike cause it revs up so high and quick about 8700rpm.

[Riggy]

i will be fitting my 4-1( cheers bruce) to my 1.4 tomorrow mate so ill let you know if it makes any difference :D

[Snowface]

i think the 4-2-1 picture at the top is for an XE as i've seen other Janspeed manifolds for Novas that are 4-1. Unless they do 2 types (which afaik they don't).

http://i23.ebayimg.com/01/i/02/aa/45/f7_1_b.JPG

[Dave]

i'm running the janspeed 4-1 on my 1.4sr afaik you have to but most of the system as they don't line up with the standard one.
is ok though

[MechaT]

According to engine building books I've read:
a good 4-2-1 increases mid-range torque and is good for road cars. 4-1 is less resrictive at high revs, but losses a little low to mid-range torque.
BUT either is much better than a standard manifold.

[Ste_Nova]

i ran a 4-1 on my 1.4 and my 1.6..... when i sold the 1.4 i put the standard 4-2-1 back on..... it was slower and didn't rev as freely

[j1400]

The one in th etop pic is the janspeed effort for the 1.4/1.6 16V engines.
A 4-2-1 manifold is the better design of the two types, but you are limited by the length of primarys and secondarys you can use while keeping it in the same dimensions as the OE set up. The point is to optimise cylinder scavenging via pulse tuning. The BTCC cars run 4-2-1 manifolds, and having seen on that Ashley made for the proton team they're massive, like it's manifold, silencer, i.e it went all the way to the rear sus of the car :o
A 4-1 does loose slight amounts of power in the midrange area, but you'll notice the gains at the top much more, esp if you have a higher rev limit and have a cam in the engine. But as said they are better than the std item.
I run a 4-1 manifold myself, and found it to be better than the 4-2-1 janspeed offer, but I have no data to back that up.

[m.d.]

oops sorry you are right, its the other way round from what i said,

i have an xe one on my 8v and it made it much more free reving so i think anything is better than the standard cast one

[Snowface]

Thanks.
So a Janspeed 4-1 or Ashley 4-1 are going to be better than the standard 4-2-1 sr manifold i got on. (is Janspeed better?, more money)

And i need a new middle section? or midle box to maniofld section?

I got the 1.2 section i took off, that might fit.

And do i need to get the 1.4sr/sri/1.3 sport manifold or the 1.2/1.3sr one?

I got a 1.4sr system on at moment.

Will the 1.4sr/sri manifold have a hole for lamba sensor? i obv don't need a hole in it.

[Riggy]

well i fitted my 4-1 today and it makes quite alot of difference , it now pulls more through the gears and revs up easier :D

[Snowface]

is that ashley or Janspeed?

[Riggy]

no its a msd i think but it the same as the 2nd pic :D