True, maybe its suitable size. I was just curious if he just used them because they were cheap, or if he actaully figured they were a correct size.
I saw that a few other people have used 50mm throttle bodies and seem to like them, so its probably a decent fit.
Oh, new posts on my topic :eek:
What you stated about individual cylinder volumes between M42B18 and S50B30 is true. However, intake port shape and dimensions on M42 and S50 heads are 99% identical so in that sense it is perfect match.
Also, while stock M42 revs to 6800 and S50 to around 7250, mine will rev atleast to 8500 so even if my individual cylinder volume is smaller than in S50B30 my engine will suck in more cylinder fulls of air in same unit of time. It is hard to say how much it will have effect in practice.
One has to remember that intake path tends to increase in diameter when going away from intake valve. So if you place throttle body close to intake valve 45 mm might be perfect. But if your throttle body is further away then 50 mm might be optimum. It is not just the diameter, it is where the throttle is located
Engine bottom end parts are in balancing and I should get them next week. I think I have all the parts now to assemble bottom end. I will make new ITB adapter from thicker aluminium (15 mm) and I will also make 10 mm Nylon thermal barrier spacer between cylinder head and ITB adapter to keep intake path cooler. I have intake trumpets made from 50 mm diam aluminium tube, I just need to make flanges to attach them to throttle bodies.
Parts for fuel rails are ready, I just need to braze them together. I cleaned few sets of injectors:
And I will service them with new O-rings, filters etc.
Superlight clutch/flywheel and hydraulic co-axial slave cylinder are in car and they work very well! Clutch pedal travel is perhaps 1/3rd what it was with stock setup. Also, the engine gains and loses revs like you would not believe! You have to be pretty quick on normal road speeds when shifting, otherwise the revs drop too much
3.45 -> 4.1 diff ratio change was installed and it is working fine, no extra noises. With only 140 hp stock engine, car accelerates in significantly different way, especially on 1st and 2nd gears. No wonder, diff is about 18-19% shorted now.
Oh, I also installed quick ratio Z3 steering rack that I found for 150€. Not tested on track yet but it feels faster but heavier when parking. I think it is going to be a hoot in track :p
Right now I am looking to buy good suspension, I swapped stock suspension to E36 M3 suspension and it is too tall for lightened 318is. I am looking AST Sportline II, Intrax RSA and KW Clubsport.
