Supercharges vs. Engine size.

[Stealer Of Souls]

3200 normally...mmh turbo teritory... Plus Revhead honestly when you are attacking the twistys do you no have the engine ringing out in the top of the rev range?...I on I do, but maybe thats because I dont have any FI...

I think there is a fair share of it is desirable flexibility. Sometimes not having to shift down a cog is a good thing. Low speed corners where you can maintain 2nd instead of having to drop to first, ring the nads off the engine, only to shift up one second after exiting the corner would be a good example.
But true. Generally speaking I guess that not many of us muck around in low rpm when going for gold...

My solution... Twincharge... Now if only I can make it work properly....

[Mr Revhead]

no i dont have it on the redline exiting corners! well i try not to
i like to exit a corner in the midrange so iv got instant acceleration.
as iv said before, i far prefer midrange torque to top end hp.
to use top end power you have to work the gear lever more, each change slows you down!

[Adamal]

to use top end power you have to work the gear lever more, each change slows you down!

Dead right Warwick. I'm really suprised as to how many people don't understand this simple concept

[Mr Revhead]

also being near the redline midcorner can be bad.... watch what happens when u hit the limiter right when you NEED power

[RomanV]

I hardly ever make it past 6000-6500 RPM in the SW20 in the bendy bits.

I usually hang around the 4000rpm mark.
There just arent long enough straights to fully wind out the gears.
And that's where the max torque is I suppose.
But I suppose a 3S isnt as peaky as a bluetop.

[Ako]

Can someone PLEASE define midrange?



Car with a 7000rpm redline

Turbo'ed, can safely say you'd be getting useful power at 3000

Thats a lot to use, and I can't see how you think a supercharger can be any improvement here.

I think, like I said before, the issue is RESPONSE, not the boost threshold. There's a difference. And a properly sized turbo setup will be quite responsive once revs are up - if this wasn't the case, we'd be seeing a lot more s/c instead of turbocharged cars both on the racetrack, and out on the showroom floor.

[RomanV]

Yeah, if you're going below 3,000rpm, you're probably doing something wrong.

[Malcolm]

of course, if you have a 3,000rpm powerband in a SC assisted car (say from 2,500-5,500), or a 3,000rpm powerband in a turbo assisted car (say from 4,000rpm to 7,000rpm) the amount of shifting required is going to be no different. With the turbo car you can sit at 4,000rpm around a corner and have plenty of headroom for powering out at the exit.

Realistically you can get turbos that will produce full boost under 4K and still pump enough air for 7,500-8,000rpm without choking up. With the turbo you're going to have less parasitic loss, and probably going to make more power and go faster.

The great thing about turbos is they take what is essentially wasted heat energy that is produced as a byproduct of normal engine operation, and use it to improve performance. With a supercharger being driven from the crank you're not making use of wasted energy, but rather you are taking a big slice of the energy created to accelerate engine revs and using it to improve performance

[Dell'Orto]

Realistically you can get turbos that will produce full boost under 4K and still pump enough air for 7,500-8,000rpm without choking up. With the turbo you're going to have less parasitic loss, and probably going to make more power and go far.

Exactly, TD05's and CT20b's are a good example of factory fitted turbos that do this well, and give huge midrange

[barryogen]

My solution... Twincharge... Now if only I can make it work properly....

super and turbo would be nice... super to fill in the bottom to 4k, turbo kicking in at ~3k, I think I'd like that.

Surely it is only a matter of tuning?

[Dell'Orto]

My solution... Twincharge... Now if only I can make it work properly....

super and turbo would be nice... super to fill in the bottom to 4k, turbo kicking in at ~3k, I think I'd like that.

Surely it is only a matter of tuning?

If it was, dont you think it'd be more commonplace

[Mr Revhead]

it all goes back to the use.....

some things just suit a s/c better than a turbo.

And a properly sized turbo setup will be quite responsive once revs are up - if this wasn't the case, we'd be seeing a lot more s/c instead of turbocharged cars both on the racetrack, and out on the showroom floor.

once the revs are up.... with a s/c there is no waiting.
have a look around, s/c are becomong very popular again as OEM.

some ppl just prefer the way a s/c feels. i know i do. i have yet to come across a turbo that can match a s/c for response.

i think some of you are thinking im saying turbos are crap and everyone should use s/c. im not saying that. what i am saying is s/c have there place, and in some applications are better than turbos

[Dell'Orto]

i
have a look around, s/c are becomong very popular again as OEM.

I believe thats in part due to emmissions regulations...something about turbos cooling the exhaust charge and making the cat less effective....something along those lines anyway, I forget the exact reason.

[Malcolm]

twincharging = waste of time IMO. Interesting from an engineering standpoint, but what's the point? What form of racing do you require power from idle to redline so bad that you can afford to add lots of extra weight and other parts to break?

[Mr Revhead]

yea they can slow cat warm up.

[fivebob]

to use top end power you have to work the gear lever more, each change slows you down!

Whether or not it slows you down depends on how you drive it, often gear changes, especially downshifts, can be made at a time where they have no effect on you point to point time, and sometimes short shifting on upshifts will be a better option, it's not always about revving the crap out of it.

In saying that it's a learned skill and takes practice, I got plenty of that riding 250 and 350cc production two strokes motorcylces for 15 years, both on the track and on the road. Got pretty good at the left foot shuffle, and could keep up with, and even sometimes ride away from my mates on their 1000cc+ bikes without a problem.

[Mr Revhead]

yes that was a rather broad statement wasnt it

it takes practice and what works at one place may not work elsewhere... all part of driving not i say driving, not riding those nasty nasty motorcycles!

[fivebob]

it takes practice and what works at one place may not work elsewhere... all part of driving

Works fine on the MR2 Turbo and the Caldina

not i say driving, not riding those nasty nasty motorcycles!

Still got a far faster track time around Taupo and Manfield than any I've seen posted on this site (but I may be wrong), and that is on a bike with no more than 50Hp, I won't embarass the car drivers by using my 250gp bike as a comparison

[Mr Revhead]

lol what i was meaning was some corners are different.
bah i know what i mean


never said slow, i said nasty

[fivebob]

lol what i was meaning was some corners are different.
bah i know what i mean

I know what you mean, but all that takes is a slight adaptation to the technique, if you downshift while braking and make sure you in the right gear before the apex then no time is lost, hardly ever need to go below 3rd with the 3S-GTE so there's only one extra upshift at most, and in the longer corners that can be done just as the corner opens up so no time is lost. Besides which most times when you are at 100% effort you are traction limited, not power limited, and that midrange torque can be a hindrance not a help.

never said slow, i said nasty

Never said they weren't Nothing nastier than having to sit behind a blue smoke express in a sardine can, wouldn't be for long though