On the K series 1.8 non VHPD engine how much boost will the engine take !
SUPERCHARGED UNIT:
Spec is as follows
Low compression forged pistons
Forged Conrods
Uprated crank
Balanced engine.
Piper 270 duration cams
Big valved & Ported Cylinder head
Uprated Cylinder head gasket
Large Bore manifold with L/B exhaust
Remote stat
Extra oil cooler
Charge cooled
Extra 2 fuel injectors
Emerald ECU
Small belt driven supercharger (will run upto 1 bar)
Car is currently running 0.55 Bar of boost with peak power being at a lowly 5,900 RPM. The torque is at a slightly lower RPM.
The question is to anyone with experience of these setups, can i run more boost in order to obtain another 30ish BHP with matching torque. I have the fascility to add more fuel as i am way of max duty cycle on the injectors. The engine running temps at full boost currently are spot on and the engine runs if anything a touch cold with the remote stat set up. I have a very good closed induction system and feel that the current chassis set up would handle the extra power, just not sure how to get it, or who to turn to for help ?
Currently approached
Minister
PTP
Turbo Technics
QED
BBR
But none of the above have been able to help improve on the setup i have already as for them it was new teritory…
Generally speaking superchargers tend to get rather inneficient beyond 1 bar of boost. turbocharging is normally a better way to go above this sort of level. to get 450BHP you will definitely need more than 1 bar of boost.
On a serious note, your peak power RPM looks low, how is the SC geared?
The parasitic losses on a SC will be very high, acheiving 450 nett of losses will be a challenge.
180lb/ft at 2000 RPM is only 68BHP, you will need to shift six and a half times more air to make 450 even if the parasitic losses remain the same and the VE doesnt drop off and that is highly unlikely. If you make 300lb/ft at peak BHP you will need to peak at near 8000RPM to make 450BHP… dream on.
Besides the pipe dreams, more than 1 bar of boost and the efficiency of a SC drops.
Ok, time to try and answer a few of the questions. Turbo technics are not doing any more high powered conversions and are therefore not available for comment so to speak !!
I was also surprised at the power and torque being so low in the RPM range i can only think that this is a cam timing issue (I have not checked this though!!)
My engine is currently 230 BHP with 211 Ft/lbs torque and i am looking for 260-280 at a maximium I believe this is achievable with less than a bar of boost !!
However i have posted on here to try and obtain some valuable ideas and more importantly your experiences and actual facts so that i can go away and achieve this goal…
1444s will be way too much cam and will require significant changes to the head, 1320 or BP285 cams would be a much more practical proposition and will give a very good torque spread. I would also try to reduce the CR lower than 9.5:1 if possible.
As to how much boost it will take, get it to a dtno…
Some great info there; however I am only wishing to uprade the power and torque slightly. A full rebuild with expensive components is not a viable propersition for me at the moment. The engine currently has only done 4,500 miles and is already lower than 9:1 compression. it has the Turbo technics strengthened bottom end and balance. it already has forged pistons and rods, and i really wanted to stick to 1.8cc. My budjet would allow Dyno time, new cams, head work, boost upgrade and the labour time in order to fit, fettle and re-map. Are we concluding from this then that an extra 30 BHP will not be achievable without a full mega spec over bored engine ?
Once again keep the advice coming as it is most welcome !! If the two Guru’s who are currently responding have any contact details; maybe a works number i would be more than happy to ring either of you for a more detailed chat which hopefully could lead to some work !!!