jonny s2

iTrader: (12)

Remember the feature on yours, still got it somewhere

nice machine

whatever happened to it??

gus

iTrader: (1)

yeah it takes a bit of working out, funny watching people follow the pipework

one fella at central day trapped off with 'whats the oint of sticking turbo bodykit on a shitty xr3'
then went on about the ins and outs of xr and s1 and how you know a turbo'd engine from a n/a engine and so on

did make me laugh

T28 RST

Got broke up and sold

jonny s2

iTrader: (12)

Haha....quality, Gus what was the first manny like with alternators? as it looks quite close

jonny s2

iTrader: (12)

like most nice escorts then

gus

iTrader: (1)

was fine mate

but as i said i have both ceramic coated inside and out

so guess this will help

T28 RST

Scott_Rst

Stunning bit of kit! How much were they to buy?

T28 RST

About Ł700, that was about 7/8 years ago

gus

iTrader: (1)

jesus was it that long ago

vroooom ptssssh

Gus - your new mani is a magnex XR2/3 manifold modified from the collector to accept the turbo

I binned the exact same one that was on the green shed when I broke it oops

Pulse speration is basically dividing the manifold into 2 banks (if 4 cyl) i.e. cyl 1 & 4 and cyl 2 & 3 are grouped together if the firing order is 1-3-4-2. #1 is ending its firing stroke and opening its exhaust valve while cylinder #2 still has its exhaust valve open (on overlap) so #1 will pressurise cyl #2 whereas if you seperate the manifold so #1 can't interfere with #2 ALL the gasses from #1 will go to the turbo to help spool up time at low RPM's but the turbo must be pulse seperated also, here's an example of a pulse seperated 2wd cosworth manifold

Rogeyboy

iTrader: (2)

That AVA manifold looks wicked, does it retain the original turbo position?

Are the auto specialists "tubulars" anygood?

A modded XR3i magnex is a good idea for turbo repositioning!

vroooom ptssssh

Rogeboy - Yes turbo is retained in the original pos with ava manifold

AS tubular, not so sure it's of any benefit over standard manifold other than it looks good.

Rob_DOHC

iTrader: (4)

Sort of mate, but the other way round. Short headers are good for high rpm power, longer headers or manifold runners offer superior low down power sacrificing top end as a general rule of thumb.

A really well designed manifold is worth its weight in gold, properly timed exhuast pulses etc help promote cylinder scavenging etcetc.

Rob,

Rob_DOHC

iTrader: (4)

That manifold looks soooo good. Always wondered why you didn't wrap it though mate, your charge pipe was pretty much touching the manifold....

vroooom ptssssh

Rob. It's actually long manifolds (inlet and exhaust) for peak power at higher RPM's (hence variable length inlet manifolds (they switch from short - long as revs increase, short for low down power and extend the length once past say 4k to increase top end power ))

Look at Focus ST170 for instance, long exhaust manifold, variable length inlet and ofcourse as a result it revs higher to make the 170bhp.

Short manis are good for low down turbo spool up, but you need the length for peak power at higher RPM, look at ava's manifold designs, as long as they can be!

xr2wishy

iTrader: (2)

i'm afraid rob got it right, longer runners for low down torque as it speeds up gas velocity due to more continual vacuum.
been looking into this as it happens and isn't too difficult to get something to function, but i'd just make a sacrifice in the powerband and just chuck in more boost. VML would be a benefit, but depends what level of tune you're after.

vroooom ptssssh

I'm talking about peak power high in the rev range - which means you need long headers inlet and exhaust.


if you want low down power, then yes shorter headers........

Rick

No mate, that's wrong im afriad.

vroooom ptssssh

Ok, so why do all cars that exceed 'normal' rpm's (i.e. higher than 6500) in order to gain bhp have long exhaust manifolds?

Integra type R for instance:

Focus ST170, TypeR's, motorbikes...


Revs = more bhp

Canada1

Because the "long" tubular exhaust manifold is better than a restrictive cast iron manifold.
The same tubular exhaust manifolds work great at lower than 6500 rpm also.

xr2wishy

iTrader: (2)

sorry i was only commenting on the inlet variable length manifolds where longer ones are for low down power and short ones for top end higher power.
exhausts work in a similar fashion though.

Rob_DOHC

iTrader: (4)

As above mate, inlets are straight forward (ish) regards to short and long runners. Exhaust manifolds are similar, but have to account for a number of other factors too, I wouldn't really say the integra manifold had particularly long runners compared to other lower revving cars...

The longer the pipe (keeping the diameter the same) the greater the restriction, however with a properly designed manifold you need long(ish) runners to take advantage of cylinder scavenging (extractor effect), which is why that manifold looks like that.....

Rob,