Injectors selection

[A80Avant]

both!
the motronic has up to a point the possibility to be tuned properly depending on what injectors you are using,but in your case you definitelly need tuning!!!

[kritis17]

Yes, I know Vasili!! I need a better tuning but I think I will follow you to the VEMS!!! Especially here where motronic isn't well known.

[A80Avant]

yes exactly! problem is that i have already approached both etuners and Andrianakis and im not so sure they would help. You have to be prepared to know that most things you may have to do on your own.

you can try Andrianakis once again and see what he knows or has to say.He will probably want you to buy haltech which he deals and knows how to work with.

email me !

[Bram]

ccm = hp in inline 5, but it has nothing to do with 3bar. Ccm in equation needs to be told on the pressure about to be used.

Single 044 pump is good for 550hp tops in our cars.

I've done 560hp from an I4 with a 630 deka and 4 bar fpr, so indeed, why not choose those?

I think I do not understand it, sorry. So you are saying that my 440ccm@3bar injectors are good enough for say 587 crank HP at 4 bar FPR? That would mean I have lot's of headroom

[repo]

.... Are you sure? So you are saying that my 440ccm@3bar injectors are good enough for say 587 crank HP at 4 bar FPR? That would mean I have lot's of headroom

Yes. I am sure.

And think of it a bit, what does it matter what injector flows at 3 bar if You run on 5?

But here's the catch. With 4 bar fpr and 2 bar boost, the fuel pump sees 6 bar at peak power. Normal 044 pump does not do it's best at 6 bar anymore, but You need a B model pump.

Also, I doubt any 440cc @ 3bar injector will stretch to 590cc with 4 bar. 490 more likely.

[Bram]

ok, I see it's more complicated then just doing this simple math

And as I am not an expert as you are Repo I trust your expertise. Thanks for your feedback.

Btw, I found a website with some calculation tools:

http://www.rceng.com/technical.aspx

Anybody knew this one?

[Bram]

Doing this calculation on that website from RC injectors I entered at the bottom tools my desired 450 crank HP, using 5 injectors, BSFC of 0.60 (for turbo charged cars), DC of 80% (as recommended by RC), FPR rate of 58 PSI (4bar), tells me I should choose injectors rated above 614 ccm@3bar?

I am confused now.... How can I currently have 368 HP at wheels and (424 crank HP) with 440ccm@3bar rated injectors? The correlation between the calculation on the RC injectors website I did above and my current setup seems to have no logic.

[repo]

Everything needs to be big in america.

[A80Avant]

that is the whole reason i made this thread. i got the same thing from a similar site,so i was wondering... BUT i would like it to play it safe rather than sorry,and since people have been using the siemens items without idle problems with VEMS,i think that is what i will do as well.

[porkkis]

I believe there is one very good motronic guru is in Greece, so you should get proper help if you know where to ask.

I'm pretty sure the 630 Deka can be tuned properly in motronic too. I haven't tried this yet, but I've found some interesting maps that should help me do this.
So far I've used 440cc Bosch lime tops @3 and @4 (theoretically 509cc@4) in many cars with no MOT nor consumption problems.

I know vems will handle nicely the 630's.

Repo's rule of thumb is good and easy to remember, cc = max hp in 5cyl.

[A80Avant]

believe me... i have searched quite a bit to find motronic tuners in greece and unfortunatelly although there are people capable to tune motronic of late generation(1.8/2.0T etc) none can tune the old motronics because they dont have the equipment for it.And basically i dont blame them.There are roughly 20 RS2s in greece in total and of all those how many would they want a remap? not worth the hassle.
thats why most of them use mechanical boost controllers and only make sure that they tune the fuelling properly and the rest get aftermarket ECUs

the person you may be reffering to is Andrianakis who i have been there and he has tuned a few RS2s, one with haltech and the rest with mech.boost controller.

[Bram]

Everything needs to be big in america.

Hahaha

I rest my case

[newsh]

There must be a fairly simple sum..

The injectors must supply, for stoich: 1/14th of the swept volume of the motor x RPM at redline x absolute boost pressure

(Absolute boost pressure being 3 for 2 Bar of boost)

(You'd probably use a factor of 1/12)

Have I missed something?

[A80Avant]

i just found that the 044 bosch fuel pump has a max PSI limit of 180. So that means 12.4bar

So why would 6bar be a problem for the 044 bosch fuel pump??

[repo]

Because at 12,4 bar there is no flow at all. 044 flow collapses at 8bar. I haven't seen flow chart of 044B motorsport pump. I think it flows the same as 044, but keeps up at high pressures better.

For normal 044, 6 bar is still in operating zone, 7bar barely, 8bar is out of zone. At 6 bar the flow is almost 1 liter/minute less than on 4 bar. (240lph->190lph).