102 replies to this topic

[Graeme Lambert]

Haha good luck. That many horses running around means noise!

 

To be fair, I don't care about noise. It can be as loud as it wants for me, it's the TD organisers and draconian circuits (Bedford) that are creating this requirement

 

If you want a 2.5" system with 330-350 bhp then you need a decent 4-1 manifold, forget about using any 2.5" aftermarket manifolds and get a long custom version and downpipe / cat section made, similar to the Tullet 3" manifold.

 

Really? MB didn't seem concerned with an idea of that power running through a full 2.5 system with the tullet manifold...

 

So are we saying my options are expensive 4-1 manifold with 2.5inch system, or 2.5inch tullet manifold with a 3inch system backwards?

 

G

[Nev]

350 BHP sounds fun Graeme, what's limiting the power at that level as a matter of speculation - lack of liners?

[siztenboots]

chargecooler

[vocky]

The Tullet 2.5" system was designed for 250 bhp NA or SC, the 3" was designed for high bhp SC or 300bhp.

 

The 3" manifold had to be lengthened to get the flow required and to be honest the standard z22se position of the 'manifold - downpipe' joint is totally crap.

 

The heat generated by the short and small bore 2.5" 4-1 is not ideal, I doubt you will get 350bhp with one fitted unless you create a decent bore (3") downpipe and sports cat section.

[vocky]

350 BHP sounds fun Graeme, what's limiting the power at that level as a matter of speculation - lack of liners?

inlet manifold

[CHILL Gone DUTCH]

Heat will be biggest issue

[vocky]

SC exhausts have been tried and tested quite a few times over the last few years, 2.5" doesn't work well past 300bhp. 

 

I strongly believe Cliffe's car lost bhp due to having too small an exhaust with the Harrop.

[Graeme Lambert]

The Tullet 2.5" system was designed for 250 bhp NA or SC, the 3" was designed for high bhp SC or 300bhp.

 

The 3" manifold had to be lengthened to get the flow required and to be honest the standard z22se position of the 'manifold - downpipe' joint is totally crap.

 

The heat generated by the short and small bore 2.5" 4-1 is not ideal, I doubt you will get 350bhp with one fitted unless you create a decent bore (3") downpipe and sports cat section.

 

No Cat here. Just a decat silencer

 

So looks like my best option is a 3inch system with the 2.5inch manifold, and bugger the noise (and invest in a silencer addition for tracks)

Edited by Graeme Lambert, 31 October 2014 - 05:28 PM.

[Graeme Lambert]

Can't help but think a chat with Dave Hardwick might be in order...

[CHILL Gone DUTCH]

x2 if it gets us a better price GL

[CHILL Gone DUTCH]

Are you still keeping it as a 2.0 litre graham ?? FYI my 2.5 tullet system flat lines quite a bit at 305 hp I'm not 100% but I think it's limiting my power It also blows the packing out regular But this has been better since I changed product for packing Also my cat made a run for it after the SC conversion

[Aerodynamic]

If you should build a systmet with varius diameters you should have it as big as possible in the beginning and have a cone atleast 15cm long from for example 3" o 2.5" and hen go to for a 2.5" exhaust on the end. Sounds logical to me. BR, Per

[smiley]

On my stage 2 i destroyed the cat on the 2.5"" tullet.

On my stage 3 without cat i blow out the wadding of the tullett backbox within just a few trackdays and i need db killers.

 

Is anybody succesfully running that HSJ cat on a >300hp system?

It may come to that expensive piece i'm afraid

[Exmantaa]

2.5 is not robbing that much power from a harrop, but if you really want to get high numbers you need 3". But the noise.... :-(

[Exmantaa]

@smiley; you know what we run on track. And pass the test. :-)

[Graeme Lambert]

So I'm thinking...

 

Retain 2.5-inch tullet manifold

3inch exhaust therein back, with decat silencer. Largest backbox we can fit between the subframe points (around 800 or so mm) and a set of interchangeable tailpipes just like Techie has (an OEM look twin, with one blocked up, a drooping pipe like Cliffies race car and a single pipe that extends out past the clam to allow proper secure fitment of a dB reducer).

 

Thoughts?

[Exmantaa]

Look into the 2bular decat resonator silencer.

[haggi961]

Mines roughly running around 380 bhp and it's not blowing any packing or anything like that. When it was 340bhp for a guess it blew the cat out and also the packing, but the packing was only rated to roughly 600 degrees. The stuff I have in now is 900 degrees. Done a couple of track days this year in it and everytime its 103 db. I've got a ticking noise when cold and gets louder when you Rev, it goes away onces warm. It sounds like when the standard manifold cracks. My Afr has increased which makes me belive there's a leak in my exhaust system. I've checked all the exhaust over and the manifold is the only bit I can't check due to being wrapped. I sort of think I might have a crack in my manifold due to the power and will check it soon as I'm going to get coated. Would it be possible to crack a Chris Tullet manifold? Theres a few other things I think the noise could be like evap valve needing changing and my car is due a oil change and sort of remember last year it started ticking until I put the fresh oil in.

[Exmantaa]

Yes, you can crack a 2.5 mani with the harrop... 3" should be netter, but could still crack (ticking noise, like a lifter)

Edited by Exmantaa, 31 October 2014 - 11:24 PM.

[Zoobeef]

103 limits you to not many tracks though!