Easy/cheap ways to improve low end torque?

[Cobb]

Changing your launching rpm is one way to increase torque and how fast you accelerate and your shifting rpms. My sidekick I release the clutch at 3 grand and shift at 5500. First gear is soo low it just takes off vs squeal. Im sure there is a bit more wear than using a lower rpms, but I want a better clutch anyway.

[theaveng]

A "little" more wear? 3000 vs. 0 rpm is a lot more wear. For my hybrid I take off as close to 800 rpm as possible, to minimize clutch wear. The electric motor provides the torque.

Originally Posted by Baltothewolf

I read about advancing (or is it retarding?) the timing 1-2° but does that really help?

My Honda Insight with it 11.5:1 compression ratio does this automatically. All I have to do is run octane 91 gasoline (which would be considered 'standard' in Europe).

Many modern cars do the same thing. I just saw an interview with a Ford engineer where he says their engines detect higher octane mixes & advance the timing to increase MPG.

The new 13:1 Mazda engine runs okay on subpar 87 but advances the timing on 91 octane. (In Europe Mazda increases to 14:1 ratio, and recommends 95 octane.)

[Cobb]

Baltothewolf, the cam timing or valve grind kind of determines where the power or torque is. The VVT, VTEC, etc helps to extend the torque or power band to cover a wider range.

Many geo, suzuki owners use a cam wheel to offset the cam timing to lower the power band. The Geo metro xfi infact came with an offset to do just that to make better use of the higher gearing.

You can find plenty of cam wheels on ebay for the older hondas and try advancing it between 3-10 degrees.

If you got a Honda with the IMA, it gives 100% torque just above idle, then it falls off as rpms climb. If you get a change to drive a gen 1 insight or stick shift crz you will see what I mean. You can easily, effortlessly shift it to 6th gear to 25 mph and accelerate slightly. Once you get past 2 thousand rpms the acceleration drops off.

[chefdave]

Alfa on their two litre 16 valve twin cam had a variorator which chsnged the length of inlet manifold to deliver a flat power curve. at 4000 rpm it switched a flap then took off again. 0-60 7 secs 135mph topend and an easy 40mpg if driven within speed limits. loved mine until 150k miles and immboliser probs made cost effective repairs a non starter. £1000 to sort imobilelizer out £300 for new clutch timing belt £500+. List goes on car was worth less than £3k.

[whatmaycome14]

Originally Posted by chefdave

Alfa on their two litre 16 valve twin cam had a variorator which chsnged the length of inlet manifold to deliver a flat power curve. at 4000 rpm it switched a flap then took off again. 0-60 7 secs 135mph topend and an easy 40mpg if driven within speed limits. loved mine until 150k miles and immboliser probs made cost effective repairs a non starter. £1000 to sort imobilelizer out £300 for new clutch timing belt £500+. List goes on car was worth less than £3k.

That reminds me a lot of the variable intake runners on some 90's Toyota's. The 5E-FHE engine had one.

[some_other_dave]

Originally Posted by theaveng

.... All I have to do is run octane 91 gasoline (which would be considered 'standard' in Europe).

Actually, they use a different octane scale. (RON, as opposed to AKI.) So their 91 is basically our 87.


A number of cars over the years have used variable-length intake manifolds--most of them done by having a butterfly valve that closes off a longer section, or opens up a resonating chamber. I recall that some later Honda Preludes did, as well as the aforementioned Alfas and Toyotas, some Porsches, and some of the more exotic Italian metal. I'm sure others have also had some way of either making the path longer or making the air "think" it was longer.

A very, very few have used variable-length exhaust manifolds. I think it's too expensive to make articulating bits that will hold up over the long term under the high heat and moisture content of exhaust gases.

-soD

[Ecky]

Originally Posted by theaveng

A "little" more wear? 3000 vs. 0 rpm is a lot more wear. For my hybrid I take off as close to 800 rpm as possible, to minimize clutch wear. The electric motor provides the torque. My Honda Insight with it 11.5:1 compression ratio does this automatically. All I have to do is run octane 91 gasoline (which would be considered 'standard' in Europe).

I'm not entirely clear on this. There are some over on InsightCentral who claim going above AKI 87 yields no benefits in the G1 Insight. I've actually returned better numbers filling up with 87 than with 93, but basically within margin of error.

@Balto, I'd experiment with advancing timing. Even if you do lose a bit of part-throttle effiency, with your gearing you're probably able to maintain very high loads at any reasonable speed.

[Cobb]

I can say the gen 2 is similar. With between 89 and 91 you get better mpg, but its not cost effective. If you keep your foot in it and have a cvt, it has more guts so to speak in regards to how it varies the rpms and acceleration.

93 is another story. Many cases you arent getting true 93 and when you fill up it adds to the fuel already there and becomes less than 93 octane. After a few tanks of 93 I started to loose throttle response like on the 87 stuff. I then backed down to 91 octane.

Originally Posted by Ecky

I'm not entirely clear on this. There are some over on InsightCentral who claim going above AKI 87 yields no benefits in the G1 Insight. I've actually returned better numbers filling up with 87 than with 93, but basically within margin of error.

[cRiPpLe_rOoStEr]

Variable exhaust:

https://www.youtube.com/watch?v=VN3bFiwQMos

A more sophisticated version is used by Ferrari. Waaay more sophisticated

[Baltothewolf]

Thanks for all the help guys, but I think I'll just continue shifting at 2750-3k RPM. I had no idea how effective it would be and quite frankly I'm amazed. I don't always shift at those RPM ranges but when I'm Highway driving I do. First gear is 3k, second is 2750 and 3rd is 2750 then 4th to 5th is either 2500 or 2750 depending on wether I'm going to drove at 55 or 65. Seems to work pretty well.