scoobykevuk

ok,i replaced my turbo hoses on my 95 classic uk as someone had butchered them and i was only getting 0.7-0.8 bar,fitted the new samcos,reset ecu(i think) and ran down the road after disconnecting the plugs under dash, am touching 0.9 bar again now but it hits 0.9 then drops off to 0.8 is this normal??std engine,cheers

joey_turbo

iTrader: (26)

That's boost spike. Most turbo car suffer with it on their standard boost controller. Someone correct me if I'm wrong. Anyway, spiking is to be expected, doesn't mean anything is wrong.

rossi_classicwrx

yeah i think thats completly normal.. my car always did the same.. would go up to about 20psi of boost then drop back to about 18 and hold there

scoobykevuk

would fitting an mbc or electronic boost controller sort this??or help to hold it better?

joey_turbo

iTrader: (26)

Yes, mbc's don't spike no where near as much, or it's very un-noticable.
A Dawes type controller I have on another car never spikes, because they have ball and spring type openings, whereas a bleed valve is more of a tap, so it can leak air back, spiking.
I'm not sure about electronic controllers, it depends on what type of bleed system they use. I doubt very much if a decent one would spike.
Anyway its not a major issue, and there is nothing wrong with the car. Its just what standard controllers do.

scoobykevuk

thanks for your help buddy

joey_turbo

iTrader: (26)

no probs.