carmad
Posted a lot
Posts: 2,000
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Aug 11, 2008 19:22:32 GMT
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i understand the basics lower compression suck / blow ect
but say on a fuel injected car like the bmw 325 i
how do they get the engine management set up to run a turbo ?
there is stacks of vids like this on u tube
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Aug 11, 2008 20:06:21 GMT
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best suggestion- read a book about it. all the theory can take a load of explaining. you might as well know why you need to X or Y aswell as why you don't need a blitz super huge monster blow off valve or other X, Y or Z item  that way you can know what to get rather than let some internet cowboy tell you that you need to spend £2k on a truck load of trouble get maximum boost by corky bell and read it well. its a great bit of ground work and you could build a decent low pressure system for street with this book and a little nouse |
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Aug 11, 2008 21:02:00 GMT
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its not that complicated, as the turbo blows in more air, your fuel system has to spray in more fuel and your ignition system has to chance its advance curve, thats either done mechanically for older cars or electronically within the ECU, getting everything spot on is trocky but the idea is simple. check out some info on Turbo Technics older aftermarket kits for some nice simple ideas, some of them are a bit heath robinson.  |
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Volvo back as my main squeeze, more boost and some interior goodies on the way.
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carmad
Posted a lot
Posts: 2,000
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i have saw a few home brew turbos
the old 2 head gasket trick ect
i have saw people using a 5th injector on a switch does this just dump more fuel in and is that why they can only run low boost as they would melt the standard internals if it was turned up
also am i right in saying its better to run slightly rich if you can
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bbq
Part of things
(. )( .)
Posts: 485
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Yes, you should run it richer than stoichiometric, ideally around 12.5:1 for maximum power. Detonation is much more serious on a turbo motor though, and will kill it incredibly quickly.
Best option is to run Megasquirt or similar. That way you can be in total control.
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2003 Suzuki Wagon R+. Feel the POWAAARRRR!!! 1968 Volvo 142. My street/strip car. Currently fubarred, it will run one day. 1971 Volvo 142. Parts car. Stripped and gone. 1993 Nissan Sunny diesel. Runs on cooking oil!  [/UR |
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carmad
Posted a lot
Posts: 2,000
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Aug 12, 2008 17:13:41 GMT
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not really fussed on mega squirt (cost)
i have saw old fuel injected vauxhall 2.0L 8 valves and they go well till they blow up
wanted to try a home brew turbo on a old fuel injected v6 i have and just run low boost for a bit of fun
4 head gaskets should be fun and i have access to cheep and new turbos
so any cheep and easy answers please
also where would you hook up vacum lines for the actuators? do they go straight in to the inlet manifold so when theres a vacum the dump valve or waste gate will release?
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Aug 12, 2008 18:18:33 GMT
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don't lower the CR. seriously, drop the boost a bit and have a higher static CR. will give better off boost driving and raise the detonation threshold significantly. if you drop the cr by more headgaskets (just don't!), you lose the squish area and thats important in not having it blow up every five minutes. efficient intercooling, correctly sized injectors, adjustable boost referenced fuel pressure regulator and thats a big chunk of it sorted. reliable power without the "bang! it broke" the ignition is the harder part to modify from oem. e36 325i would work easy as its knock sensor based. e30 would be more involved. keep it under 9-10psi if you want it cheap. more and its hassle and money. and i know this as I have read the books |
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carmad
Posted a lot
Posts: 2,000
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Aug 13, 2008 17:31:44 GMT
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whats the difference in the knock sensor engines ?
i understand that if a knock sensor detects to much vibration it raises the air / fuel mix and causes the car to rev slightly higher to smooth the running ?
how would this be an advantage?
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Aug 13, 2008 17:49:10 GMT
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knock sensors detect pre ignition which is the mixture igniting before it should, its caused by hot spots in the cylinder or to much ignition advance, this is very bad as you can get the explosion trying to force the piston down while its still on its up stroke, it can eat away bits of the inside of your engine or totally destroy it.
The knock sensor listens for the vibrations (and noise?)of pre ignition.
If the ECU (using the knock sensor) detects pre ignition, it can retard the timing till it stops. I think some of em can make the mixture richer as well which will also cool the combustion chamber.
An engine that uses knock sensors is a good thing as it means you can run more timing adavance for better power and economy.
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Volvo back as my main squeeze, more boost and some interior goodies on the way.
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Aug 13, 2008 17:51:31 GMT
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whats the difference in the knock sensor engines ? I understand that if a knock sensor detects to much vibration it raises the air / fuel mix and causes the car to rev slightly higher to smooth the running ? how would this be an advantage? A knock senor is a crystal that creates an electronic pluse at certain frequencies, det/pinking/knock produces a certain frequency and when the knock senor tells the ECU there is knock. The ECU usually retards the ignition by a few degrees until the knock stops, the addition of a knock sensor increases reliability. Edit: Damn you popup for getting there first! |
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Last Edit: Aug 13, 2008 17:53:35 GMT by Robinxr4i
Sierra - here we go again! He has an illness, it's not his fault.
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carmad
Posted a lot
Posts: 2,000
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Aug 13, 2008 18:37:39 GMT
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lol i don't care if theres 2 answers sometimes they both make sence
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carmad
Posted a lot
Posts: 2,000
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Aug 14, 2008 17:54:02 GMT
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bump any more suggestions?
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that way you can know what to get rather than let some internet cowboy tell you that you need to spend £2k on a truck load of trouble 
