forevaford

iTrader: (2)

hi,
why dosen't my zetec turbo rev?
its got 270 bhp peak at 5200, that should be more like 6700 if you ask me. it running 20 psi,
i think its a flow issue, maybe my manifolds of turbo choice, but when you drive the car it really runs out of puff and you have to change gear to make it go again. my limmeter is only set at 6200 and i hardly ever reaches that.
my spec is as follows;
8;1 comp ratio with accrilites
modified escort rs turbo exhaust manifold
rs18i inlet manifold (aluminium type)
stage 3 t3 turbo
2.5 inch through exhaust
standard 2.0 cams
ported head and manifolds
uprated valve springs from area six (3 years ago)
i recon it mite be the s2 exhaust manifold not flowing enuf, and/or the stage 3 t3 turbo a bit too small??
the car really goes well, but just reaches a natural govener too early.
any advice is appreciated, thanks

forevaford

iTrader: (2)

0-60 is 4.6, and quarter mile is 13.9.
so im not complaining too much, its just bugging me, ino their is more to be had from this little gem of an engine.
im thinking t34.48 then it might rev higher then 6??

crazycage

are you maxing out your injectors?? could be the t3 but couldnt be sure

p-s what is your trap speed on the 1/4mile

szabyk RST

iTrader: (1)

cam timing??

crazycage

blacktop or silvertop??

creator

the standard escort exhaust manifold has been flow tested at 350+bhp so it wont be that mate.
what managment is it on? and as crazycage said what injectors you using?

forevaford

iTrader: (2)

its running bosch 803 wit around 70% duty max,
megasquirt ecu,
its theearly silvertop zetec from m reg mondeo
valve timing is tandard except i advanced inlet cam verry slightly,
and trap speed over the line was 107 mph
thanks for the replies, i stilll think its turbo being too smallon exhaust side, ithink its a .48 housing on a stage 3 t3??

JesseT

I'm thinking that the advance on the inlet is the wrong choise for multiple reasons.
Generally if you want more power higher up on the rev range, retard.
If you are running a small turbo that creates high back pressure, you want the exhaust and inlet to have very little overlap to avoid reversal of gases --> retard inlet or advance exhaust.
If you have boost pressure in the inlet flow, you don't need to use the complete geometric compression ratio, because the amount of lost compression pressure can be subsitited with boost. So, it's ok to close the inlet valve a bit late. --> retad inlet.
Even on the RST when it was introduced, the cam was the same as in the XR3i, but retarded with a different pulley.

forevaford

iTrader: (2)

thank you Jesset,
i will do that as soon as i can, and i will update with the outcome,
maybe the standard cams are insufficient for high rpm with boost?
possibly still my valve springs, they wasnt double springs???
thanks for the info

tabetha

Turbo is fine, listen to JesseT, that would be my first suggestion too.
tabetha

forevaford

iTrader: (2)

thanks tabetha

xr2wishy

iTrader: (2)

cba reading all the replies, but sounds as if the cam profile isn't aggressive enough or the timing of the inlet is too advanced, similarly the exhaust cam could be to blame.
get it on the rollers and start moving cam timing a little.
what valve springs are you using also?
maybe they can't handle higher revs.

forevaford

iTrader: (2)

thanks to JesseT, my zetec turbo now revs to the limmeter! i had the rocker cover off today and retarded my inlet cam (its just a nats cock before standard now) took it 4 a spin, and wheel spin all the way to the limmeter... great!, in the wet tho
so thank you, much happier now

clarke5700

https://passionford.com/forum/non-fo...ics-added.html

my-first-rst

sounds like my zetec turbo, and thats down to fueling? although since i have put a t3 on mine it seems alot slower !

cossie4i+

iTrader: (15)

Back on the rollers then to see what difference it has made

Steve

forevaford

iTrader: (2)

yep, it sounds like it, its dear tho to keep paying for rollin road sessions, im just going to use it now, and tell every1 its 300 bhp lol
thanks again for the resolution