BIG problem with power

[speed_devil]

Hi everyone
I have 106 rallye s1 with vts 3 plug engine.
Some time ago i bought colombo&bariani cams with 260/9.0 and 270/9.6 spec,
with this http://www.passionesaxo.com/Bitubo2.JPG + Jr sport replacement air filter and the car got 139bhp at 7500rpm (i think it's ok or a little bit downside..) Then after some time i make engine rebuild (new rings, shells...), machined my pistons(for valve clearence) and bought newman ph4 cams. After assemling the car it was up again on the rollers and it was same result - 139-140hp at 7700rpm. The man who is mapping the car tryed everythink(fuel changes, timing...) but it's every time like no change 136, 139,137.....
I have a questin. My exaust line have 48mm diameter and my back box is magnum supersprint(which seems to have very little entry and exit like 40mm???). Is it possible that my problem is my exaust ?
Pleas help. Any ideas are welkome!

[Liam_]

Supersprint systems have 2" pipework so should be good up to 160ish BHP? I'm assuming you've removed the CAT?

What is a 'Jr sport replacement air filter'... a panel filter for the standard airbox?

[speed_devil]

yes i have cat removed.
and yes it's a panel filter for standart box.
sorry for my english :)

[deesvtsT]

anything with the power of that must have a min of around 2inch 2 1/4 even better try it witout the backbox if the chap mapping it can stand the noise get a decat as cats restrict the power

[speed_devil]

yes we can remove the back box for a test....
i have removed the cat

[Liam_]

Could try asking your mapper to remove the standard airbox (run just the open throttle body) and see if the figure changes? The air feed is totally laughable imo - it seems to a do a 'loop the loop' before reaching the scoop on the slam panel.

anything with the power of that must have a min of around 2inch 2 1/4 even better try it witout the backbox if the chap mapping it can stand the noise get a decat as cats restrict the power

Surely removing the back box won't make any difference as the pipework up to the manifold is still 2" bore?

[deesvtsT]

worth a try bud check the air fuel ratio at high revs see if it leans off if dose maybe a higher fuel preshure reg or bigger injectors

[speed_devil]

it ok 11.9-12.2 at 7500-8000 range

[deesvtsT]

ummmmm tough one will sleep on it bud got work in mornin cheers will get back to you if i think of anything witch will help

[SaxoJamie]

could ask the garage to perform a compression test see if the engine has enough compression. Could also be dodgy spark plugs, fuel injectors etc

[saxova]

He stated that he has changed the rings/shells etc, so cant see it being compression.

Also i thought ph4's required throttle bodys? Certainly not trying to run these on std air box? :O

[speed_devil]

i run them on standart air box with a replacement filter....

[saxova]

maybe not enough air is your problem?

[makaveli144]

ph4s on a standard inlet?

Thats more than likely your problem

[speed_devil]

yes i don't want to go for tb's because i use the car every day and i don't want stand alone too....
So meybe some kind of peugeot sport intake manyfold is my decision ? or c2 ?

[saxova]

use the car everyday so i'll throw some ph4's in, wise choice lol.

[Aron]

C2 VTS metal is suppose to be good. PH4 will struggle on standard. Newman PH3 should get you more power then that.

[Liam_]

I'm sure I read of someone on SSC running something like PH4's with a C2 VTS metal inlet manifold and Clio Sport 172 (PH1) throttle body. Will need a little fabrication to make an adaptor plate up for the throttle body, but should make a healthy difference.