Mike Rainbird
The reason the high comp engines give relatively low torque is as Chip explained - high comp engines can't run as much boost as low comp engines. Boost = torque.
not strictly true there
Bosch-Man
Also Mike you say lo comp can run higher boost...yet a rally car runs a 3bar boost spike do they not on like 9.5-1 engines and make about 500ft lb.....IF hi comp was so spaz why dont rally cars run lo comp and get more reliability...there must be an advantage to hi comp
and the rest , cr's are way higher than that pal on WRC
Itsmeagain
RACE FUEL you fool.
If you ran their engine specs on pump fuel itd end in a big bang very quickly, and if you re-mapped and re-boosted their engines to run safe on pump fuel you will have fuck all worthwhile.
fookin bollox, 90 % of the clubman rally cars will NOT run race fuel, only a very small percentage will due to the costs, the gains are not enough to justify the costs, and is not necessarily needed cue ........tim finch,
clubman rally cars do include wrc and group a vehicles on a regular basis.
chip-3door
IF your brief it so hunt for as much torque as possible (ie the thread subject) on an unrestricted (ie not a rally car which are limited by rules) engine then you want low cr.
If rally cars didnt have the restrictor, they would run lower CR, simple as that, the high CR is there because the restrictor is there
far from the reality, why would we want to bother making the car a complete laggy peice of shit for no reason ? we all have air restrictors, yours may be known as an inlet plenum, mines just in the intake to the turbo
i can still run 2.4 bar on a T34
i also have a map in my ecu for when i run non-restricted, i dont have a switch to instantly drop the CR, nor would i want one.
Itsmeagain
Low and High is relative purely to the fuel used tho IMO.
And as we talking about pump fueled road cars, Mike is right.
We not talking about restricted, race fueled, cars.
For the race fuel they run, WRC engines are quite low comp, but theyd go far lower if they didnt have the restrictor, they need to make the most power from the RESTRICTED airflow they got, with the fuel they got, hence the comp they use.
Simple maths that theyd do.
We havent a airflowe restriction.
more inexperianced bullshit
im not going to quote anymore of this thread, i think you can see, the people who comment on hi v low, have not had/used a high comp motor for any particular reason, just out of interest, what do we constitute as hicomp these days for a YB ?
8.0 :1 ?
9.0:1 ?
higher ????
i know what ive run for the last 7 years as hi comp, and trust me, by todays standards its no where near hi comp
but i like it, it drives nice, performs nice, and has been very reliable.
as for egt's etc , well , bad heat managment will always end your engine, especially if your just gonna read a book about it ( sorry internet forum) like alot of what seams to go on these days, if one person says its wrong every one must be wrong.
dont forget though guys, the YB series is essentially a late 1970's engine really, and although mick and keith though brilliant engineers, they did not try every engine , in every scenario, in every condition, to very spec.
