Torque increase?

[Mochi]

I have an '06 xrs with typhoon intake and performance exhaust. It drives really well , though I am wondering if there is anything I can do to increase midrange power (torque)

[Jason.MZW20]

Originally Posted by Mochi

I have an '06 xrs with typhoon intake and performance exhaust. It drives really well , though I am wondering if there is anything I can do to increase midrange power (torque)

Not really. The normal cam profiles are designed for low-mid range power as it is. Torque is mainly a function of displacement. If you want more power, you need to either increase the displacement or increase the amount of air/fuel the engine can use (forced induction).

The 2ZZ is a peaky motor. That's just how it is, so you'll have to hit lift to get any reasonable power.

The Elise and Exige have supercharged versions of the 2ZZ. You could look into that.

[silver04rollas]

Well, my XRS is putting down 171 wheel HP on the dyno (that is 193 HP at the crank). I have an Injen cold air intake and Greddy exhaust.

Granted, there were healthy gains of around 15 - 16 wheel HP from these mods making it quicker than many V6 and some V8 cars provided the stock airbox and exhaust are very restrictive, they give a much better midrange, but still most of the gains are over 6000 rpm and last up to 8400 rpm. I also have lightweight wheels and rims.

I would recommend you getting lightweight wheels, lightweight performance tires (tirerack has weight for tires and you want ideally around 18 - 19 lbs per tire) and also you can get a lightweight flywheel (it will rev the car up much faster making it very lively at every rpm making the pull in lower gears 1st through 3rd much harder).

Since torque is a function of the displacement of the engine, most of the torque in high-revving engine comes from multiplication of torque through short gearing. Therefore, your best bet is to work on the responsiveness and lightening the rotational mass of the car, which will make the car very responsive even at half throttle.

Granted Corolla XRS is 250 lbs lighter, all of these mods will make your car very responsive and pull from any gear, at any speed. I have lightweight wheels and lightweight rims and it has made the car extreme responsive and very torquey in the midrange.

Footnotes:

- Get lightweight wheels
- Get lightweight performance tires
- Get Fidanza racing flywheel (7.5 lbs) to lighten the internals up even more. It will make the car suddenly feel 150 lbs lighter due to lighter internal rotational mass.

and also,

- Injen cold air intake
- Magnaflow full catback exhaust

All of these mods will make the car pull hard even part throttle in higher gears at low speeds. If you need further clarification, do ask.

[Mochi]

Thanks for the replies. I've got the intake and catback/Borla exhaust which helped a lot, but you know how it is you always want a little more.
Don't want to go f/i, I'll look into the flywheel/wheels.

[silver04rollas]

Originally Posted by Mochi

Thanks for the replies. I've got the intake and catback/Borla exhaust which helped a lot, but you know how it is you always want a little more.
Don't want to go f/i, I'll look into the flywheel/wheels.

Don't forget to look into lighter wheels as preferably in the 16 inch size. How about downshifting?? When you have a high-revving car, you need to love throttle-blips and downshifts in matter of split seconds.

Trust me. Do the Fidanza and ACT stage 1. You will LOVE the feeling and thank me for that. It will so much more lively and the throttle response would be razor sharp. It will take some getting used to since the revs change very rapidly and a bit more throttle getting off the line especially on uphill starts since lighter flywheels store less inertia, but once you get used to it, you will not ever want to go back. You would love doing throttle-blips, heel-toe downshifts because the car will rev so fast.