) to reduce front weight and while i was at it, it seemed rude not to play with the suspension geometry!. http://www.wallaceperformance.co.uk/ Should be fun!
Some very good points, however compunded turbos do work. Here is a link to a guy in the states running a compound 4G63T (NOT an EVO). he is running the same times as he was with his GT42rs (and 150bhp shot for spool) but without the gas.In a true compound charge system it's down to blower sizing, blower drive ratio and turbo housing size as to how much power is made. If the blower is big enough, it would always multiply the turbo boost within the blower efficiency range so sizing of the 2 compressors is paramount.
Of course big HP figures aren't always best. On a turbo engine, the power comes in hard when the turbo spools and although a higher HP figure can be achieved, it's at the expense of a driveable motor. On a compound system, the low end torque and power can be hugely improved and if it's setup well enough, similar top end figures can be achieved and make the car quicker point-to-point than the bigger power turbo motors.
Packaging an Evo engine bay of any twincharge system is a nightmare - trust me. So many things needed changed or modified to allow this to work.
A big turbo feeding a smaller turbo wouldn't work very well - your total flow would be restricted by the smaller turbo and with using 2 turbos there would still be a lag issue with no real power gains IMO.
It's not all about more boost
on a serius note a larger turbo SHOULD produce the boost at lower temps and i dont think lag will be an issue for you any more!From what I can tell from the pics, the turbo fees into the charge cooler. this then gose to the supercharge. form the supercharge the air is routed to the intercooler at the fornt of the car. then to the intake manifold. This layout would make sence. you will need to cool the air after the trubo and before the SC.
Sounds like you have it covered mate! Also the advantage of ICE over dry ice is the cost! like you said its going to be pretty easy to 'make' some more ice, or even go to the local supermarket and buy some for a quid, if you need more. However dry ice is not so easy to come by! Or just take the frezzer with you and make some at the event! lol. How cold can you get your frezer to run at? just thinking if you could cool the ice further. Could you get it down to -10C?.....Chris, thanks for the valued input.
The tank has been designed to use ice blocks at the moment. If i wanted to use dry ice, i'd have to modify the tank with another heat exchanger because at the moment the iced water is pumped around the chargecooler.
The problem with dry ice is getting a reliable supply that will last the weekend and also to get the heat transfer it has to be mixed with isopropyl alcohol as a 'mush' to be effective. Probably too effective as the mush would be at around -60c which would then freeze the coolant that is pumped through the exchanger and chargecooler! That would also be too cold for the fuel as ideally fuel should be around 0c. Any colder and there's a risk of splitting hoses and the fuel rail , and of course the injectors wouldn't like that! From my research, going colder than 0c on the fuel has no performance advantages.
If the ice block method isn't effective enough, i've been looking at other ways to use the dry ice. It would be possible to fill the tank with water/anti-freeze to -30 and use dry ice to cool that to -25 or so then pump it through the chargecooler. I'd have to experiment with that of course and there's still the issue of the fuel being too cold.
I think it'll be fine with the water/ice blocks. I have an old freezer in the garage so can make large quantities of ice and a few large insulated boxes to keep it frozen. Until i try it, it's difficult to know how well it'll work though. The way this has been built i can drain off some water then add ice and pump it through before reaching the start line. That should last for the entire run (between 28 and 90 seconds depending on the event) and once the ice has melted, drain off more water and add more ice. Hopefully it'll be that simple:smthumbup. The ice can't enter the system or pump due to a mesh
I already carry ice to the meetings to keep the beers and jerrycan of fuel cold so no biggie to take a bit more
Cgood to hear that the water temps are still below Ambient after the run. Be intresting to see how efficent the charge cooler is at reducing the post trubo air temps.
Also it would mean alot less weight in the car as you would only need a small tank and say an aquamist injection setup. Aslo you could then spray pre 'second compresor' as that would help with efficeny of that unit. and then maybe use the third nozzel just before the manifold. You could still use the super cool slush as that would no doubt help even further! No rpoblems mate. I'll keep coming up with the wacky ideas! :bored: :frust: :shake: :smthumbup: :smthumbdo: :wallbang: :mhihi: :coolsm:
:angel: lolMac,Grant, yep i agree we're getting close to what the block can handle at the lower RPM. This is something i will address on the new engine but i will struggle to fit a dry sump system due to lack of space for the oil pump(s). The alternator is now in the place of the aircon pump and the supercharger is in the space where the OE alternator was.
I was looking to have a cradle made which cross-bolts through the sides of the block then having it in-line machined to suit the block. We used to do this on the Rover V8 engines with good results. This was after i split a V8 block in two
I bet you end up running them at full speed the whole run!329mm, twin speed so i can increase cooling on the start line
lol and if that still not enoughthen i bet you could get a twin core rad made pretty quickly using 2 x rads.
