Roller TB Air filter upgrade cutout necessary?

[Rattie]

Having had a look at a friend's CSR Superlight I noticed (quite quickly) that despite having the 2.3 l duratec with the cosworth roller TBs and the associated foam air filter, it manages without a bonnet cutout for the filter.

 

Is a cutout absolutely necessary for the CC offered Titan(?) roller barrel upgrade (aka R300 175 to 195 bhp kit)? Are the trumpets longer maybe, or could you just give it a bit of a squish?

 

Just an idle thought

 

Martyn

^_R300GRR

[P W]

The CSR is wider remember. Unless you have an SV I can't see how you would get away with it but I could be wrong? I've a CSR (they are the same barrels not Cosworths by the way) and the filter touches the bonnet so I would say you need another inch or two to clear in a standard chassis.

 

[Rattie]

Interesting, we do indeed have an SV. I should have mentioned that. Interesting that they're the Titans on the CSR. That does bode very well for an upgrade without bonnet butchery. = 😬=

 

Martyn

^_R300GRR

[Jason Plato]

I wouldnt go rollers.

 

I prefer the part throttle behaviour - which is most of the time on road, of the butterfly throttle bodies.

 

 

here is my Duratec R .... C7 TOP

Taffia AO

[7 wonders of the world]

Throttles will give better transitional response etc, which is why most of the BTCC and rally guys use them, you can just squeeze DTH TB under an S3 bonnet without a cut out however you need very short trumpets (ideal being 90mm) it also helps if you opt for the short bell housing as this moves the engine further back into the wider part of the bonnet.

 

A cut out will offer the best performance option though if your only looking for 195BHP you should be able to get this using the OE plenum set up.

 

Too young to be old !

 

Edited by - 7 wonders of the world on 13 May 2010 08:59:53

[Rattie]

Interesting stuff. Bear in mind that we have an SV so space is probably not an issue.

 

So how would you characterise the difference in part throttle behaviour between rollers and butterfly throttle bodies?

 

Martyn

^_R300GRR

[regroo]

Rollers give better full throttle power 'sometimes' because at max opening there are no restrictions in the inlet. Everywhere else in the throttle range part of the 'ball' is protruding into the inlet which upsets the airflow when compared with a traditional butterfly which flow more evenly. Speak to a couple of engine mappers and you will soon find most of them find roller barrels more difficult to get the best from on anything bar full throttle.

 

The difference driving with either of them depends on your style, if you thrash the living daylights out of your car everywhere then it wont be that much of an issue but normal, on/off, part throttle on the road something like Jenvey's will give you a much smoother and faster pickup. Alternatively there are 'spindleless' butterflies but the last back to back test I saw concluded that there wasn't the advantage that was being clamied by the manufacturer....look nice though 😬