Mercedes CLA45 AMG 2.0L I4 Engine... Almost? Help w/ TQ Plz.

[WildKarrde]

Can anyone explain to me how to increase torque? The only way I really know how is to increase stroke... but that's not a sure-fire way to make it happen.

I tried to replicate the Mercedes CLA45 AMG engine, which blew me away when I found it it produced 355HP from only 2.0L... but the Mercedes engine also produces 332ib TQ. I could only produce 292 TQ by the end of my development phase (aka. youtube video). So my HP is right... but my torque is 40ib off.

Anyway, here's the video:
http://youtu.be/gkKq7s7qUJs

What am I doing wrong for torque?

[Der Bayer]

The turbo seems to be way too big for the engine size.

[WildKarrde]

Does a bigger turbo reduce torque?

[Der Bayer]

If it barely spools and does not build up the boost, yes.

[Slim Jim]

Almost forgot...

The turbo size I used to get pretty much exact numbers: 48mm compressor, 54.5mm turbine, 0.97 a/r ratio, 20.1 psi max boost (ball bearing/medium water-to-air intercooler). I had to mess around with the rest of numbers (including liberal use of the quality sliders) to get the numbers just right.

So what was it I almost forgot? Technically, I can't share my engine file/screenshots until the next version is released.

edit: The open beta has just been released, so I can post the files I uploaded before... (if I only waited another hour or so LOL).

[brock500r]

It is a very hard engine to replicate as the torque 332lb ft @ 2250-5000rpm and the mercedes runs 26psi of boost so small high pressure turbo try and get the A/R enough in the rev band im going to have a go at making a A45 engine


Here is my results

[headacheengineering]

don't bother the benz uses a Variable Nozzle Turbo, the turbo available on automation is the normal one, so there is no way you could replicate it.

[brock500r]

Ahhhh i see so they are now using VNT on petrol's now like diesels have been for years makes sense thanks

[WildKarrde]

SUCCESS!!!!

Sorry I haven't been back in a while, but when numbers started getting posted I went away. I needed help understanding torque but I wanted to figure the engine out on my own. I see Slim Jim beat me to it, lol. Anyway, thanks for the tip with the turbo stuff. I finally got time to sit down with Automation again today, and figured it out!

The turbo settings I used were a 52.0 compressor, 43.5 turbine, 1.04 a/r ratio and 25 psi max boost. I also modified quite a few other settings in the engine to get the numbers exactly right. The YouTube video is below for anyone who's interested in seeing my process.

http://youtu.be/cfRRA_5qK9s