just a few ideas i had today, thought i’d share em.
#1:
A button on the testing page, where if you press it, the engine just sits there and idles till you tell it to stop.
#2:
Also on the testing page, make it so can you edit the engine name by clicking where you want, instead of having to delete and retype everything
#3:
add spark plugs 
#1-that would be pretty nice
#2-IIRC that will be fixed at some point, maybe in the revamp
#3-Not really a useful feature, it would be a fair bit of work for very little gain
#1- We are thinking about a free-revving option… idle only would be pretty meaningless IMO.
#2 - Definiteley!
#3 - Uhh… no. Sparkplugs are too minor of a detail - we discussed that and chose not to include it.
I had this idea for a while but havent remembered to actually post it (most likely you have a better solution but Ill just post this anyway 
): I think the rpm’s of the engine should be controlled with the movement of your mouse. First you would bring your mouse over the sheet where it displays the rpm, torque and HP, and then you would “start” the engine with lets say clicking your right mouse button, and then just control the rpm’s with moving your mouse horizontally in that sheet. This way you could leave the rpm’s running on something like 3000 rpm’s just by leaving your mouse there.
While a good approach this has some serious flaws: it would suggest a “no resistance” environment as you can change RPMs in no time, which doesn’t sound good. A better approach would be roughly how you describe but with throttle instead. But we’ll see!
Now that I read my post afterwards, it didnt exactly sound like it but that is what I actually meant, a “gas pedal” on the data sheet following your mouse movement (well yeah it would not have to be on the data sheet but this way you would not have to change your interface). But I can see that it would not just be a piece of cake adding that kind of system into the game, since the game would have to take into consideration of how easy or non easy revving the engine is. But if done correctly, it would be awesome to actually experience that great responsiveness of your companys newest sport car engine!
PS. When is the engine revamp coming? Next week?
another thing i’d like to add.
will twin-charging be available? i.e. having a v6 with a supercharger, and twin-turbochargers at the same time?
for a good example look up the Lancia Delta S4.