canny title to make you read (no offence the yb is cool)
anyway what i mean is i hear lots of you (yb's)running 22,23,24-27psi of boost and only making between 300-350bhp maybe?
thing is i made 336bhp with only 17-18psi which is great. however i wanted more power
my mapper says he can't fit anymore boost in,as it starts detting.
he says i need to lower the C/R before he can do anymore!
so by lowering the C/R and then returning to the same boost will i have less horse power than before?
effectively needing more boost to make the numbers?

 

Depends on turbo and injectors really!

 

as in, a smallish turbo needs to make more boost to flow as much air as a bigger turbo?

 

Mine made 507bhp @ 1.2bar which is around 17psi, on simons Dyno so better rethink your first sentence .

 

knowledge gathering

 

Rods also made 350hp on 7psi

Mark

 

As i am sure Mark will agree tune an engine for power gains rather than just running big boost.

rods car, a great example.

Spend some money on a decent head, ports, cam choice manifold mods correct turbo for mods etc and you will be pleasantly surprised at power gains without having to run dangerous boost levels.

WRC escort cosworths were restricted to the amount of boost they could run, however they make outrageous amounts of torque around the 600lb/ft mark due to heavilly tuned engines.

 

Mates running 427bhp but thats at 35psi

 

nice . mine at 8psi

 

at what revs?

 

 

I cant remember that rpm but it made 613hp@6.8k

Mark

 

Outrageous.

 

impressive

 

 

Lee there has to be more to your lack of power(unable to get power) problem than just comp ratio. A local lad round my area has the same turbo as you and on a std inlet is running 398 on 1.4 bar,i'm not 100% on his comp ratio though but i'm pretty sure its still in the 8's. How is he able to fit the boost in without det'ing?
Robbies LET made 530 on 1.2bar(gt35r) and Adaptec made 400hp on 7psi. I'm sure the LET is just as good for big power as the yb just seems everybody prefere to use what be tried,tested and race proven

 

we've put the problem down to me fookin up basically, i changed my spec on accident or by my lack of knowledge. i had a measured 7.9:1 C/R but then i had a head skim and reduced head gasket thickness it may have been that more got skimmed than i knew, and we're estimating C/R now to be 9.0:1

 

9:1 is fine mate,just move to solids and rev the nuts of it
No wonder its making good power on low boost eh

 

i could go higher on the revs to get round that but i might want the higher revs for madder things at a later date

 

Thats was at 2.2bar on pump fuel,

 

Mark Shead