The Lotus Cars Community banner

21 - 40 of 91 Posts

·
Registered
Joined
·
2,308 Posts
I've already got a mustang Gt engine ready to go in so no I wouldn't be interested....just kidding...me no wants to void the warranty and Im quite happy with the performance as is...for now.
 

·
Banned
Joined
·
6,941 Posts
FWIW the 2ZZ-GE is not too far away from being a maxed out NA lump. Some of the Celica guys that have turboed or SC'd their motors grenaded them. If you do bump the output I'd say it would be a good idea to smooth out the transition to Lift and to try to retain NA type throttle response so that the handling can be retained.
 

·
Registered
Joined
·
677 Posts
Discussion Starter #23
Stan said:
FWIW the 2ZZ-GE is not too far away from being a maxed out NA lump. Some of the Celica guys that have turboed or SC'd their motors grenaded them. If you do bump the output I'd say it would be a good idea to smooth out the transition to Lift and to try to retain NA type throttle response so that the handling can be retained.
That is exactly what I am looking for Stan.

I think 230 to 240 HP can be acomplished with a supercharger and a few engine tweaks. 230 HP may sound like a small increase for the money, but the peak HP number is not the important number. The important number is the HP increase at low RPM before the high RPM cams engage.

BTW, there are a number of reliable 2ZZ engines that have been professionally boosted all the way to 300 HP with no problems. Of course, there was little stock parts left in the engine after the full build was complete.
 

·
Registered
Joined
·
7,710 Posts
as ive said.....if u wanna do it, ya gotta do it right....get another 2zz, rebuild it, and keep ur stocker in the corner of the garage..
take the rebuilt motor build the heck out of it, THEN do ur supercharger....and dont forget to LOWER your compression...

racerx- thank you....ur allright in my book...:)
ur ok too stan, but i think u would have been happy if they put the toyota echo engine in this car...:) ha

this car would be VERY fun with 250 at the wheels.....
stan, that might be enough to smoke a zo6 at the quarter..:)

the only thing is, i dont want to build this thing to where its hard to drive as a street car....time will tell....
 

·
Registered
Joined
·
677 Posts
Discussion Starter #25
By my calculations, 250 HP at the wheels would be 11.84 seconds in the quarter mile (if you have enough traction).
 

·
Registered
Joined
·
1,114 Posts
Stan said:
FWIW the 2ZZ-GE is not too far away from being a maxed out NA lump. Some of the Celica guys that have turboed or SC'd their motors grenaded them. If you do bump the output I'd say it would be a good idea to smooth out the transition to Lift and to try to retain NA type throttle response so that the handling can be retained.
Stan,

Very true. Word from Lotus UK is that the engineers have been working on a SC 2ZZ-GE base motor for the new S2 Exige. But, they are blowing motors right and left.
Now, if the factory Lotus engineers are having these problems what makes the guys on this list think they won't blow them:confused:

Best Wishes,
Mitch
 

·
shay2nak
Joined
·
25,083 Posts
count me in, too!
 

·
Registered
Joined
·
866 Posts
What about addind a thick head gasket? I would think that a few mm on the gasket would decrease the compression enough to make it possible? I don't know about all of the calculation involved in that, but I would think it would be cheap and act like a little bit of insurance. Of course, the Redline might have to be reduced, and that might mean the cam profiles need to be reconfigured. Who knows, I guess time will tell.
 

·
Registered
Joined
·
677 Posts
Discussion Starter #30 (Edited)
So, should I post what I have so far and enter it into the public domain?
 

·
Registered
Joined
·
1,063 Posts
aletes said:
Engine Cooling 1 of 1:

Now the engine water-cooling circuit would be overloaded at this point, so the stock radiator will need to be upgraded. Pace Products makes an upgraded "race" radiator for the Lotus Elise, which fits the requirements perfectly.
You'll have to experiment, but that may not be needed.. The Elise is hugely 'overcooled' in it's radiator capacity as it runs in stock form.

Even the Honda K20A and Audi 1.8 Turbo powered Elises (with really silly power numers now pushing 300HP) still run with the normal radiator in place.

Most people upgrade to the different rad once the normal one blows up (often the plastic end tanks crack or the rad itself develops a crack which leaks..)

So this my be a 'nice to have' option, but not a real hard requirement. (although I can imagine that it's more of an issue in very hot climates..)

Bye, Arno.
 

·
Registered
Joined
·
323 Posts
Aletes

A cooling system as shown below ( comprising a 2nd cooling loop for the after - cooling of compressed air ) is used by Lotus in the former turbo charged Esprit and still now by Turbo Technics in their SC kit for the Rover- Elise .



It comprises an additional water pump ( Zusatzpumpe ) and a Low Temperature Water Cooler.
In the Elise this cooler has to be located upstream of the main cooler like the condenser of the AC system, which might be difficult in case you cannot abstain from AC because of very hot temperatures during summer season.

But if you can then the condenser might even be used for water cooling. (details to be checked ).

Also the Laminova water to oil cooler might be connected to that separate lower temperature cooling loop ( downstream of the after cooler ).

BTW you wrote :
>>> I would prefer the Autorotor or Lysholm due to their low RPM boost characteristics, but I suspect that the Rotrex will be the only choice due to size and heat constraints. The Rotrex is very small and generates less heat than the screw type superchargers. The drawback is that the Rotrex is a centrifugal supercharger which provides boost at a higher RPM than the screw type superchargers. <<<

So far I thought that small centrifugal are less efficient than screw type compressors and therefore generate MORE heat not less heat.

Please write me a PM.

Cheers Rüdiger


PS
@ Arno
I like that rator shown above because it `s all made in Al.much better than having those plastic chambers with leaking gaskets
 

·
Registered
Joined
·
402 Posts
SCE Copper Head Gaskets?

Has anyone tried lowering the compression with a copper head gasket?

www.scegaskets.com

I believe SCE makes these up to .094 thick which might be a real clean easy way to lower the compression to the 8:1 - 9:1 range.

-Jim
 

·
Registered
Joined
·
323 Posts
Aletes

You certainly know that charge air T should be as close to ambient T as possible.
If you cannot have an air to air charge cooler then you need a separate water cooling loop as shown above.

I cannot believe what you heard about the efficiency of small centrifugal compressors. Do you have a diagram as shown in:

http://www.lysholm.se/PDF/diagram_lys1600ax.pdf

or

http://www.lysholm.se/PDF/diagram_lys2300ax.pdf ?

( Small must not always be beautiful )

If you still feel uncertain you should consider that even TT who use that small centrifugal compressor have the Esprit –type cooling system in their supercharged Rover Elise I showed you above.

Regarding the AC –condenser. I feel that it will still operate behind = downstream of that additional water cooler. Some Miata owners and also Jacksonracing ( I like their charge air cooler) may be able to confirm this.

Having the condenser and that additional water cooler upstream of the main water cooler, some call it the “rad” may be too much for this one but you still have the possibility to make it thicker and you have 2 fans in the Fat –Elise.

Regarding the additional water pump ( which I am missing in the Jacksonracing kit ) see:

http://www.daviescraig.com.au/main/display.asp

But you can get a very similar pump from Bosch, too.
In case your are interested I can mail you a WORD file showing a commun h Q- diagram ( Pressure over Liter ) of both pumps.


BTW: To lower the CR with a thicker cylinder head seems to work in many motors.
It has been done also in some turbocharged Rover Elises though that engine is well known because of its HGF problem . Time will tell how long such gasket is able to keep water and engine oil separated from each other there .
But I would try this approach in case the original motor already has high quality pistons.
For the Rover engine it `s better to get other ones anyhow.
If you do not reduce the CR you are not able to reach much more power output and all the above mods are waste of money.

Rüdiger

PS
In my Miata I have a 0,6 bar turbocharger and if the Elise had a FRONT ENGINE I always would vote for turbochargers but its engine sits behind me and there it `s very warm already without such device, even here with our moderate European climate.
 

·
Banned
Joined
·
6,941 Posts
It's much better to lower compression via special pistons. They'd have to be compatible with the mmc bores though. Our stock pistons are iron/tin plated. Normal pistons can be used if you convert to iron liners by machining the block.

If you ever do bore and iron line the block it would make sense to change the centerlines a bit. You can slightly move the outer pistons further apart in the inline direction. Then move the inner two further apart. This will allow a modest amount of overboring to gain cubic inches while retaining the ability to rev. If you stroke the motor it will be less rev happy and will wear more at high Rs. Of course...you could do both... Some related custom parts, experience and set up will be needed!

The reason using a thicker head gasket is not so hot is due to a thing called quench. You can retain proper quench with pistons having the correct dimensions near their perimeter. Basically a stock distance from the piston top at the perimeter to the combusion chamber portion of the head when the piston is all the way up to the top of the bore. When you drop in a thicker head gasket you drop compression but you also increase that distance. Quench helps stave off detonation because it helps the mixture move and mix properly so that it burns evenly. There is a great deal of effort put into achieving things like this. Without proper quench out 11.5:1 motors would not even be possible. So in one way you cut detonation factors (<compression) and in another you increase tendencies (<quench) if you drop in a thick gasket. All else equal it means that you have to drop compression more than expected in order to be safe. Something like an extra 0.5 to 0.8 of compression for moderate amounts of boost at a guess.

For the cost of such a FI motor, get fancy, high tech pistons. Some who modify the 2ZZ hear it called a "glass engine" in that you can grenade them if things aren't just right. I don't know if I'd be that harsh on the lump but it pays not to push it too hard while being cheap.
 

·
Registered
Joined
·
7,710 Posts
good post stan.....
as ive said many times, if your gonna do this, do it right. take your stock motor out, and go rebuild another one to put in the elise. if u wanna supercharge this car, build a motor with lower compression forged pistons and forged rods.

stan, i didnt think u could bore this motor because the cylinder walls are too close?? i thought if we stroked the motor it was from a different crank size or something???

stan, we might be able to keep a stroker at the same high rpm if we use some fancy lightweight rods and pistons...

when u do work like this you cant cut corners and doing it right is expensive...
 

·
Banned
Joined
·
6,941 Posts
>>>stan, i didnt think u could bore this motor because the cylinder walls are too close?? i thought if we stroked the motor it was from a different crank size or something??? <<<

If you do what I mentioned, you increase the distance *between* the cylinders a bit. So then you can overbore a hair.

>>>stan, we might be able to keep a stroker at the same high rpm if we use some fancy lightweight rods and pistons... <<<

Piston speed at a given RPM is not affected by the weight of the moving parts. If you go higher on piston speed by stroking, to keep about the same longevity you need to reduce the redline by about the same amount. So essentially if you stroke to gain go from 1.8 to 2 liters this is about an 11 % increase and torque will tend to go up by about that amount especially down low and into the midrange. The cam lobes will act milder. The extreme top end power at the same revs as the stock size won't go up much if at all without other steps.

The piston speed of the 1.8 liter lump at the Lotus transient redline of 8600 would have to go down to about 7600 or thereabouts to keep comparable longevity when stroked to 2 liters. Look what Honda did when the S2000 engine was bumped from 2 to 2.2 liters.

If you add FI and figure that you have more going on down in the RPM range, great. But you will also need to shift sooner, hence lose the gearing factors presently helping us out. This means that you won't get as much of an actual car performance bump as the dyno sheets may lead you to believe. Since if you shift at 7600, the stock Elise still has another 1000 RPMs to go until it needs to shift hence it enjoys the torque multiplicative effects of a lower gear longer than the modded car.
 

·
Registered
Joined
·
323 Posts
Aletes

Thank you for that rather convincing link to the Rotrex SC. Seems really to be a good choice. Somebody having a TT –SC –Rover Elise here wrote that also the noise level produced by that compressor is not too much disturbing him.
Whereas the Eaton / Jacksonracing kit one of my Miata / MX5 –friends has installed makes an horrible noise.

Nevertheless I show you a Lysholm SC installed in a Opel- Speedster boosting that L850 GM engine being developed also with some aid of Lotus Engineering.

As you know that Opel / Lotus-Speedster can also be ordered with an old fashioned but very solid cast iron turbocharged engine, produced since long for several GM cars. I mention this because it proves that also in the Elise engine bay an supercharger may be possible if you can provide proper cooling.



The next picture I got from Joe. (Hope you are reading and will give your opinion in this context, too. )



Joe `s picture shows an Eaton SC fitted very well in his Exige`s engine bay into the gap behind a Honda K 20A engine.

BTW : Joe do you really still need that heater coil we see there in front of the Honda K 20 for power output in hot CA ?
Add 1 or 2 psi in boost and a good charge cooling system as proposed above and you will not miss that very decorative but certainly not cheap piece of art. You do not have an AC in your Honda- Exige. Therefore I feel that it will be easy to install an additional water cooler in the mouth of your Exige.

I do not know whether this Honda is also a glass motor but it is some kg heavier than the 2ZZ. Nevertheless I would prefer the Honda, best in its 2,3 l version, if I had the choice for my early S1 Rover Elise.

BTW : How do you get the additional fuel into the Toyota engine ? Only increasing the fuel pressure by installing another fuel P controller will be risky and a custom made ECU cannot be a cheap one for a glass motor either.

Where are the experts required for remapping its EFI - ECU ? Can `t be that difficult because other ECUs used by Lotus and Rover in the different Elises have been decoded in the meantime , too.

Rüdiger
 

·
Registered
Joined
·
7,710 Posts
stan, if u use lighter weight pistons then yes, u can spin them higher than u otherwise could...dont know if using something that exotic would be cost beneficial here though....

hmmm.....looks like were getting somewhere on a sc that fits...
:)
 
21 - 40 of 91 Posts
Top