How do I get more torque?

[03frostygt]

I've seen some comments on this here and there but what are the best and most cost effective ways to add torque to a gt? Driving through the mountains of WVA last week the lack of torque was appparent, especially starting from a stop on hills.Thanks.

[1oldbanjo]

Unfortunately the things that make the GT a high revving horsepower engine are the things that aren't good for torgue. Agressive cams, big valves, large diameter intake and exhaust pipes all make air flow through the engine faster and make horsepower - but when you need torgue at lower rpm's the air flow through these big holes is slow and inefficient. A supercharger on a low compression engine would help torque (and horsepower) by allowing more fuel and air in the cylinder - but because of the high compresson on the GT the supercharger is not an option. Detonation at low rpm's when under a load would be a problem - and any benefits from forced induction would be offset by the engine management system backing the timing off when it sensed detonation .The easiest and cheapest way to gain torque is generally through increased engine size.....and longer strokes are the best at making torque since the piston rods get more leverage on the longer crank throws. The longer strokes can make an engine less fond of high rpm's - as the piston speed can get excessive at high rpms.I don't know if any of the performance chips help with torque - generally they are geared toward HP and the chips will increase fuel mixtures and advance timing - which doesn't help with torque at crusing rpm's.If you are really serious about needing more torque - I would suggest looking for a Toyota speed tuner that can get you a "stroker" crank setup. Most of these would involve a new or reground crankshaft with a longer stroke - and shorter connecting rods (or pistons with the rod hole located lower in the piston). A larger bore would also help with torque somewhat - but the same increase in engine capacity by stroking is more affective at increasing torque than the same size increase by increasing the bore.Another option might be if someone offers a different cam grind for the GT - one that makes a little more torque.Now for the disclaimer: My engine knowledge is "OLD SCHOOL" and comes form working on engines with carbs and distributers. When you increase the HP without increasing engine size - you very often make the car faster at full throttle and higher rpm's - but make the car less friendly to drive daily.Dave

[ToolGuy]

1oldbanjo mentions a lot of great points...Historically, if you were to look you will find most America designed engines have lots of lower end torque compared to Japanese engines i.e. Honda S2000 or Civic's. Another example; I had a 1998 Z24 with 150 HP & 150 lbs ft and that years Civic did not come close to those numbers... Different sized engines but still low for their size. Asian engines have the HP but fall short on torque plus you really have to rev the heck out of the engines to see the torque they do make. Seems engineers of engines in the States realize people want the lower end torque for city driving. I believe you are realizing what I mentioned...HP is easier to get by adding items/mods but Torque is harder to get from add on's. If you have an auto trans car I would turn the over drive off next time. You will use more gas but hold higher RPMs once you are moving.

[goodvibe]

Unichip helps a lot but is costly. Intakes only rob low end torque so that wouldn't be a good option. More of a high RPM add on.

[Mase]

Get some light 15 inch rims.

[northvibe]

I think with some basic performance addons you'd get some HP and torq.CAIExhaustGround wire kitUnichip (best help as you can tune your car)Supercharger! but its expensive ( i think greddy makes one for the 2zz engine)EDIT: oh i forgot, exhaust headers! ported stock ones or performance ones.

[1oldbanjo]

I just did some checking and Mi-Vibe Toolguy was right - these engines really rev to make torque. Both the 1ZZ(base) and 2ZZ(GT)engines have their torque ratings at 6,800 rpm!!! The 1zz has it's HP rated at 6,000 rpm and the 2ZZ aT 7,600 rpm. These ratings occur at more than twice the rpm that the engine is turning during normal steady speed cruising.Following are some statistics for the engines.Base 1ZZ engine- Bore 79.0 mm, stroke 91.5 mm, HP 132, torque 170GT 2ZZ engine- Bore 82.0 mm, stroke 85.0 mm, HP 190, torque 180I realize that later ratings for the GT are only 164 HP - but this information came from http://www.toyota-ZZ.com and does not account for later revisions (I suppose). The important thing is that the base 1ZZ engine has a smaller bore and longer stroke (undersquare) engine to make good torque - while the GT 2ZZ engine has a larger bore and smaller stroke (oversquare) engine to make horsepower. Although the GT makes more torgue and HP than the base at high RPM - it would be interesting to see a comparison of the HP and torque curves to see what is happening at 2,000 - 3,500 rpm where most of the daily driving is done. I would not be surprised to learn that the base engine has more torgue at lower rpm's than the GT.The suggestion to get lighweight 15" wheels will help you with acceleration by changing the gearing and reducing the rotational mass....it will have little affect on helping you to hold a steady speed on steep hills (except that if the tires are smaller in diameter the affect of lower gearing will allow the engine to rev higher at a given speed and make it easier for the engine to pull the car up the hill in high gear - but your fuel mileage will decrease and the car will be revving more to hold the same speed it would have had with the larger diameter wheels and tires - and your speedometer will be innacurate). These are all things that that you probably don't want while traveling on long trips. I had a VW Rabbit GTi with a 5 speed and low gearing and the engine would turn 4,000 rpm's at 70 mph! While it was great for autocrossing with these close gears......it sure got old listening to that engine whine on long trips.I am not sure that porting exhaust manifolds or intake manifolds will have much affect on torque. Although these things all help fuel and air flow through the engine easier and allow more air and fuel to enter the cylinders - their full affect comes at full throttle and higher rpm. I am not sure they wil help for an engine running at part throttle and at the lower rpm's while cruising at a steady speed. The same can be said for all filter mods, exhaust mods, etc. - their increase is usually oriented toward full throttle results and do not make much improvement on torque at partial throttle. Dave

[northvibe]

lol yea all the mods are usually for WOT, dynos showed almost 10hp/torq increase witht he exhaust headers ported. but like you said thats not at normal driving speeds. SC would be the only thing i could think of that would give you a increase at normal driving....or when trying to get from a stop to speed limit.

[AKLGT]

because there is not a SC for the 2zz engine and a turbo isn't too cost effective, i'd suggest looking at the unichip or other engine management system. I know with my CAI and unichip combo, i noticed a pretty good difference in the low end torque that was much needed.

[ColonelPanic]

Wow, 1oldbanjo - I am certainly enlightened by your post... That's some good to know stuff!Toolguy, you're definitely right on the money for the American vs. Asian torque comparison there... That certainly explains why one can find a tach that only registers 7,000 RPM and has a redline of 6,000 or so on some GM products. My Malibu was that way, had gobs of power way down low but ran out of breath in the higher revs...

[03frostygt]

Wow is right. I feel like I should have earned 4 credits just by reading the replies. Unfortunately it doesn't sound like any of the cheap aftermarket items will help (thanks for the tip about the CAI definately not helping at the low end).

[goodvibe]

You can also try some Denso Power iridiums plugs. You can get them for less than $50 and they did help mine a bit. Increasing the guage of the wires from the battery to engine and chassis ground wont hurt. Just run an extra 10 ga, to near where the current grounds are Make sure you get to bare metal on the chassis. You don't need to do the fancy looms as the chassis and moter are both very conductive and offer little resistance. A bypass cap for the battery wont hurt either. Batteries are great for storage but slow at discharge and recovery. Any breathing mod will actually hurt low torque. Better fill at high RPM will allow intake gas to escape the chamber due to lack of resistance at low RPM. It's one reason that GTs have the butterfly valve on the air box. With different intake, exhaust and cam timing, the GT could have plenty of torque with the same valve and cylinder specs. Well as plenty as a 1.8 can muster anyway.

[Lancer]

Quote, originally posted by 1oldbanjo »Now for the disclaimer: My engine knowledge is "OLD SCHOOL" and comes form working on engines with carbs and distributers. When you increase the HP without increasing engine size - you very often make the car faster at full throttle and higher rpm's - but make the car less friendly to drive daily.Dave What's a distributer? Just kidding!!

[1oldbanjo]

Well I took this link out of the "HUMOR" section - but it is applicable to getting more torque. This engine has a stroke that is 3 times longer than the bore - and it makes HUGE amounts of torque - however it will not fit in the Vibe. In fact - I believe you could probably park a Vibe in the air cleaner and not even hurt the performance.Check out this big engine: http://www.bath.ac.uk/~ccsshb/12cyl/I drove my Vibe on it's first trip last weekend and we went to West Virginia. There were plenty of interstate and back road hills to climb and I learned first hand how little torque the base Vibe has - and I can now understand why you would like to have more in the GT. There were several hills on the interstate that required us to downshift as the engine could not pull the hill in high gear. On some of the backroads we had to shift down to 3rd. I have never had a car that required me to downshift so much......but I also never have gotten 32 mpg on gasoline before. My wife has a VW Jetta diesel and we get 42 mph with it....and the torgue pulls the West Virginia hills easily..but I think the VIbe is more fun to drive and was much cheaper to buy.Dave