Modding the 2ZZ

[charlez13]

I own a 2000 celica gts and i'm also a regular poster on newcelica.org. Since the 2zz-ge is now being offered in the Elise, I figured i might help out and post up some info and links regarding performance parts available for modding the engine.

So far, the best site i have found for modding the 2zz when it comes to engine internals and such is MonkeyWrench Racing. They also have other components such as clutches, lightweight flywheels, etc.

Forced Induction Kits:
XS Engineering
c2 Power
Stafford Fabrications

Note: It would be wise to call and make sure that any aftermarket part you buy will fit the Elise before you spend an assload to buy it.


Additional Info on the 2zz:

If you are planning to use turbo/supercharge/spray with the 2zz, I would highly recommend replacing the connecting rods. Its common knowledge on newcelica.org that the connecting rods are one of the weakest points of the engine. It will be much cheaper to get stronger rods now then a new block later.

Also, the 2zz's have had many problems with people over-revving them and bending the valves. Usually this is caused by a misshift. If you plan to run at high rpms alot or raise the rev limiter then i would replace the valves and valve springs for sure.


Hope this is helpful for you guys!

[cuenant]

Thanks for the info. How do you think is the best way of flatening the torque curve. I don't know when it does on the celica but the eilse hits its second cam at 6200 RPM. Thats a bit high for me. What do you think would happen if it was lowered to, say, 4200 RPM?

[cuenant]

Thanks for the info. How do you think is the best way of flatening the torque curve. I don't know when it does on the celica but the eilse hits its second cam at 6200 RPM. Thats a bit high for me. What do you think would happen if it was lowered to, say, 4200 RPM?

[ChrisB]

Originally posted by cuenant
Thanks for the info. How do you think is the best way of flatening the torque curve. I don't know when it does on the celica but the eilse hits its second cam at 6200 RPM. Thats a bit high for me. What do you think would happen if it was lowered to, say, 4200 RPM?

If you lowered the switchover to 4200 RPM, you would lose a ton of mid-range torque. The high-speed cam lobes do not provide as much torque at that engine speed as the low-speed cam lobes. Some people have lowered the switchover to 5800 RPM, with marginal results.

The primary benefit of lowering the switchover to 5800 (on the US Celica) would be to keep the engine in high-speed cam mode throughout red-line shifting. The gear ratios in the US Celica GTS and the slightly lower redline on it than the Elise, means that red-line shifts result in the next higher gear pulling the engine down out of high-speed cam mode. Accelerating out of a corner (on a track) at the cars cornering limits and have the high-speed cam mode change could upset the cars balance.

[darkSol]

Originally posted by cuenant
What do you think would happen if it was lowered to, say, 4200 RPM?

If you were to plunk a custom stroker crank of say 5mm to raise the stroke to 90mm with custom rods and pistons that moved the piston pins up 0.137" (for a longer rod / better rod ratio) then...

a) The displacement would move from 1796cc -> 1901cc

b) The rod ratio would move from 1.65:1 to 1.54:1 (8500rpm is still possible - there's Honda boys with B20VTECs with 1.54:1 that run 9500rpm!)

c) HP / Torque would bump up about 6% or so... AND the peak torque would drop about 1200rpm... to 5600rpm.

You could get more power/torque down lower by lengthing and tuning the induction system - but you'd rob Peter to pay Paul and lose power up high above 6500rpm...

[charlez13]

Originally posted by cuenant
Thanks for the info. How do you think is the best way of flatening the torque curve. I don't know when it does on the celica but the eilse hits its second cam at 6200 RPM. Thats a bit high for me. What do you think would happen if it was lowered to, say, 4200 RPM?

Well, as ChrisB said, you will end up losing power. The lift engagement point is right where it needs to be to make the most power.


If you want to mess with the powerband and rpm's a little then my suggestion would be this...

Because of the 2zz's non-reprogrammable ecu, then you are going to have to go with a stand-alone system. The Apexi PowerFC would be a wise choice. The PowerFC allows you to mess with the lift engagement as well as the rev limiter. I would leave the lift engagement point where it is and instead focus on the 2zz's strong point...high end power. I would raise the rev limiter and try to get more power that way instead. As stated above, you'll probably want to do a few reliability mods before you go crazy with the rpms.

[fitfan]

As i understand it, the us elise will switch over to the 2nd cam at 6200 but also holds onto it down to 5,800 ... maybe someone knows for sure, but i remember reading this somewhere, about lotus working over the "drivablity" of the HP and TQ.

[mason]

From Lotus's pres release on the Exige being that the Fed Elise shares the same drivetrain and performance output numbers it should be appicable.

The very high revving engine is governed to a maximum engine speed of 8500 rpm on up changes (8000 rpm at steady state). The change from the low speed cam to the high speed cam is controlled by the Lotus engine management system to achieve a smooth transition, which will not upset the balance of the car. This change occurs at around 6200 rpm, but can vary by a few hundred rpm depending on engine operating conditions. The return switching from the high speed to low speed cam occurs at 5800 rpm to extend the operating range of the engine on the high speed cam. This helps the enthusiastic driver stay on the high output cam between gear changes.

[Onikaze]

Woo Hoo!

that, is indeed good news, its so hard to stay on the high lift cam in celica's that all i ever hear is how terrible they perform...

there is potential in the engine, its just wasted on the drivetrain (FWD) and poor engine management...

[aletes]

Hmmm ... This should give all of you something to think about.

http://monkeywrenchracing.com/lotus_elise.html

http://monkeywrenchracing.com/mwr_to...leeve_kit.html

[tracera]

A few things to think about before pushing for higher rpm', we've seen quite a few of the 2zz's fly apart at high rpm it's seems they pop right at 10,000 rpms everything from bending valves to oil pumps coming apart to the oil control valve (the one that controls the switch from small to big lobe) failing so it seems the head can handle up to 10,000 but the oil pump and some of the engine controls can't.

[MyElise]

The difference with the Elise v. the Celica is that the Elise weighs less than 2k lbs. Therefore the loss of a little midrange torque is not as detrimental as it would be in a heavier car. Additionally, many more Elise's will be on the track where the transition to the upper cam can be a problem.

Does anyone make a more radical lower cam that can be installed to push the hp/torque up a bit higher so that the transition is smooth? Or can you change the timing of the lower cam with a similar result?

[erok]

Not to steer people away from this board, but essentially all of the questions and answers about modding the 2zz engine can be found within message boards of sites like newcelica.org.

To summarize my experience with the Celica, the engine responds well to freeing up airflow in the intake and exhaust. Typically gaining about 10whp from the combination of CAI & Exhaust. The Elise already seems to have a very free flowing cold air intake through the side vents. Developments in Celica CAI designs have shown the benefit of retaining the stock airflow "fins" within the intake right before the MAF sensor to prevent a lean condition, which is the most common CEL code associated with intake mods. The stock intake pipe diameter also has been shown to work the best.

The stock exhaust header is extrordinarily effective in the Celica, with most aftermarket replacements showing dubious gains or losses in dyno testing. Simple A/F ratio controllers like the Apexi S-afc have been shown to be made worthless by the stock ecu which corrects the imputs of most piggyback devices.

The Fidanza lightweight aluminum flywheel in my car made a big difference in the fun factor, letting the engine pull harder and rev madly at the merest blip of the throttle. Is the flywheel weight of the Elise the same as the Celica? Stock Celica flywheel is 13 lbs. Fidanza is 8 lbs.

Redline fluids in the engine and transmission are the only lubricants that seemed to make a difference in my car - the engine ran a little more smoothly compared to mobil1.

People have been trying to improve on the Celica drivetrain since 1999 so there's a lot of people with answers on the Celica sites. Forced air induction mods for the 2zz seem to be a real challenge between the high stock compression and the uncrackable ecu.

This engine likes plenty of oil circulating within it. Keep the dipstick on full. Rod bearing failures have been attributed to running with low oil.

I wonder if the dreaded "mis-shift" issues with early Celicas will appear in the Elise?

In general, it is a pretty difficult engine to modify without a serious investment of time and money. Fortunately it's a great engine to begin with and basic bolt-on mods offer reasonably good effects.

[Mistertwo]

Originally posted by erok

This engine likes plenty of oil circulating within it. Keep the dipstick on full. Rod bearing failures have been attributed to running with low oil.

An oil pump upgrade of some sort might be something to look at for those who plan to rev higher or even spend a lot of time in the higher rpms. I know having the stock oil pump ported and shimmed on MR2's is common for these purposes.

[sqpiece]

Can't forget Trial:
http://www.shopts.com/trial_elise/Top%20Page.html