junaid786

what you guys think of the t3 0.48 turbine and 0.42 compressor ?

i hear from alot of people that this thing comes on boost quick but drops off at about 6-7k rpm.

my friends say i should just go with a t3/t4 0.63 turb and 0.6 comp. but i have some fears in this regard.

firstly i have seen alot of guys breaking their motors with this turbo coz it forces the engine to operate in a very high rpm range. but they mostly have 16 and 20valves. mine is a 8v so it can handle more flow at high rpm.

secondly, i would need a fifth injector or something to get in the extra fuel. i want to keep the stock cis. enriching the mixture via the lambda tower increases fuel output across the band, not just in the upper end. so my turbo would have to match my cars power band or be effective throughout the whole band to prevent fuel wastage or detonation.

would the t3 be my safest bet? considering my tachometer says a max 7000rpm( i know it can do more than that but mercedes obviously put that there to keep it within a safe range.)

busa4

the t3 .48 a/r housing will be great for low rpm boost. the t3/t4 will be great for mid range rpm power. engine life is all in the tune. pick the turbo based on your driving habits. if you need low rpm boost and you wont ever be at high rpm then the t3 .48 is best for you.

you will need an extra injector controller. its not advised to use one injector as some cylinders will run richer or leaner then others because theres no guarantee that the same amount of fuel will enter each cylinder. the best way to run an extra injector controller is by adding an injector to each cylinder runner that way there is no way to run a cylinder lean/rich.

junaid786

yes, i see they use that method with the kit they make for these cars. but its expensive.

i found out from my mechanic that the bosch injectors are quite interchangeable.

the ones for the 2.3 190e and 450 se are the same. i think they are around 575 or 600cc.

would this serve the same purpose?

busa4

there not that expensive. i paid 200.00 for my eic, 100.00 for 4 new lucas 42# injectors, fuel rail - free, fuel line- ~50.00 depending on what you use. a custom dyno tuning session can cost ~1000.00.

what do u mean interchangeable? your mechanical injectors cannot be interchanged without redoing your injection system.

junaid786

would you care to elaborate on this? what exactly needs to be changed?

coz according to my knowledge, there is no ecu controlling the fuel. my mech showed me that there are no electronic devices connected to the injectors themselves. therefore bigger injectors would mean more fuel. the mixture is adjustable via a lambda tower where you can make the mixture richer or leaner. and the airflow meter gives more fuel with more airflow.all mechanical. and the spark is contolled my the distributor that uses a vacuum advance connected to the intake manifold.

i am happy with this mechanism at this stage. as it allows me to look cool with the bonnet open and grease all the way to my elbows.lol

but really, im a bit of a traditionalist. i like the k-jetronic the way it is. it has to be a good system if i can get 600km per 55l tank. thats pretty good when you consider that its a 2.0 8v automatic with aircon and mechanical injection.

i think i myt just go with the k03 from a 1.8 audi. i know its a small turbo but it will give me the lower end torque that this car is missing. i know im not maximising this cars power band coz those huge 8v can make big top end. but im not a racer and i dont wana kill myself. so 4-6 psi at low rpm is more than enuf fun for my daily runner.

but i really appreciate you taking the time to give me advice. i would like to know more about the fuel system changes you spoke about. did you mean that for electronic fuel management?

busa4

your correct. ther is no ecu controlling fuel. its all mechanical.
the setup im talking about is an extra njector controller. this is computer controlled setup that will control extra electrical injectors so you dont have to modify the stock jetronic system. you will weld injector bungs into your intake runners so you can mount the extra injectors. the extra injectors will only come on when the controller sees boost. you tune it yourself. the only issue i see is you will need to run fuel at the injector rail and it has to be at least 42 psi. another issue maybe the controller requires a tps signal for 3d mapping but you dont have to use a tps.

junaid786

o, ok now i get it.

but it sounds a bit hectic.

i could probably tap the existing fuel line for the fuel, the bosch pump on my car is capable of 100psi but its limited to 36-48 by the fuel pressure regulator. so i could just change the fuel pressure regulator and go with the system you described. maybe later when i get the extra cash. thank you for the idea.

the logic that i am working on ryt now is that the bigger injectors will provide fuel at a rising rate as compared to the existing ijectors that provide fuel at a flat rate. the existing injectors lean out the mixture at high rpm on the N/A system. what do you think? will this method work? ie making the system add more fuel as the revs climb to co-incide with the increase in air.

busa4

it will add fuel exponentially which will work but you will not be able to control your afr so you maybe rich or lean at specific throttle percentages and rpm. fuel requirements are different all accros the rpm range. the only safe way is with computer control.

junaid786

yeah i hear u mate, damn those dollars just keep climbing

junaid786

w8, i just had a brain wave. What if i attached the vacuum advance hose thats connectd 2 the manifold to the intake pipe ie btwn the air filter and the turbo.that way it wil advance on boost and prevent detonation wen things go lean. It myt just work.i wonder if i cud keep the stock injectors and just enrich the mixture via the diz this way...