Engine tuning

[atnova]

Hey Guys,

I am currently doing my final year project, which is rebuilding an engine, tuning it and racing in an event called formula student. I donno if this is the right place to ask, its something to do with engine torque. Say if u guys are racing, would you prefer getting the max torque to come in early in the rpm range or later? Thank you in advance. Sorry if this is inappropiate!!

Cheers
AT

[Gismo]

Great question and i'm sure there will be some varied answers.
My tuppenceworth, you'd want the torque right through the rev band, but, as that's not what you asked, then, probably, depending on the track you'd want the power as early as possible.

Be interesting to see the racers answer :thumbs up:

[atnova]

well i am trying to get a wide torque band aswell but i sort of want to know if its better to have the peak torque earlier or later cus i am going to race in silverstone but the way the organisers set up the course is more techinical than usual and there is not much straight as this race i am doing is trying to test the ability of the vehicle me and my team built ahha. so it will be very likely that i will not be wot all the time if you know what i mean =]

[Mon the fish]

You want a wide torque band, as flat as possible - see a tuned R53 or R56 JCW for what you want. For racing, you definitely don't want a diesel torque band - yes, it has more torque, but it's so peaky; you'd have to short-shift to stay in the torque band.

I'd say later in the rev range, otherwise there's no point going to the redline (for racing)

[ELFMAN]

Thought-provoking question!
I would think lots of low down and mid-range torque is great for Rallying (and probably everyday driving), to help pull out of slower corners etc. As Mon said, for Racing you'd still have to have a wide Torque Band, but for it to come in higher up, as the engine would spend more time at high revs on the track. How you go about tuning the Torque Band is quite vague to me though. You presumably have to throw the Gearing of the car into the mix as well... Oh it's too complicated for me! :confused::argh:

Following on from that, I've always been slightly confused of the relative merits of Torque and Power in getting a car to shift, and where the two work together to get the job done. Is there a case for saying Torque is favourable for 'in gear' work - ie "pulling power' and Power is more of a top-end advantage. Is there a point in the 'acceleration curve' where Power takes over from Torque? I'm thinking of say, the R56 Turbo engine versus, the Honda Civic's R's VTEC. They get both cars moving at roughly the same rate, but use different mixes of power and torque (and gear changes!) to do so. I read about the whole Power/Torque thing ages ago, but it's lost in the mists of time!

[Mon the fish]

Thought-provoking question!
You presumably have to throw the Gearing of the car into the mix as well... Oh it's too complicated for me! :confused::argh:


You really notice this between pre- and post-facelift R53's - the facelifts have shorter ratios, which means they feel a bit quicker, even though they have broadly the same power (163/170 bhp)

The torque/power thing is hard to explain - power is directly related to torque x revs - this is why diesels don't produce as much power as a similar-sized petrol, as the torque drops off at higher revs.

You want a flat torque band, and the power to increase in a straight line from zero to the redline; power is a function of torque - you don't get power without torque, but you can have torque with not as much power (like a diesel).

The best way I heard it described was this: imagine you're digging a hole. Torque is the size of the shovel; power is how fast you shovel

[ELFMAN]

Cheers Mon. It is tricky to get your head round, but that simplifies it a bit. I doff my imaginary hat to you.

So my engine at the moment is a fair-sized shovel, and due to the Induction/Exhaust/ECU tweaks, it's shovelling a bit faster than it used to and producing more power higher up the rev range. It would also seem that, say, the old Honda Civic VTi (my pal had one for years) produced a lot of power from its 1.6 VTEC without (relatively) so much torque because it revved so high (8,000+rpm) with its trick cam stuff coming in - wee shovel, shovelling very quickly. Ahhh, Grasshopper Understands... I think.

[atnova]

Thanks for the tips guys
Right now i have just mounted my engine onto the dyno, i will find the current power with my current map, then start my mapping and design a new exhaust and intake inorder to get a wider torque band =] Thank you again!!
AT

[Mon the fish]

What kind of engine is it? N/A or forced induction, etc?

[atnova]

its a cbr600rr engine but its restricted with a 20mm intake =]