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Exige Rumors?

9.8K views 51 replies 31 participants last post by  Need4Speed  
#1 ·
The new Lotus motorsport exige will have 300hp while the street version detuned to 260hp. A guy on an Italian BBS just went to lotus to see the new cars.
Hmmm
 
#3 ·
I'm not too sure, didn't one of the Lotus engineers comment on the Toyota engine being able to safely produce 300 bhp.
Additionally let us not forget the old Esprits with 4 cylinder engines that were pumping out over 300 bhp.

Now how can we upgrade the Elise put out the same?
 
#5 ·
HI Derek,
But the increase in performance from the original 2 liter esprits including boring out to 2.2, nikasil piston/liners, turbocharging (up to 215 hp) then chargecooling and updating the turbo to around 285 hp.

Everyone seems to say it'd be tough to get that out of the toyota engine, but if anyone can, Lotus can.
CHris
 
#7 ·
I do not believe even Lotus can get 300bhp from a normally aspirated 1.8 liter 4 cyl. They must be talking about a turbocharged engine if they are using the Toyota block.

The only way a normally aspirated engine can make significantly more power is either through 1) more displacement 2) higher compression 3) more revs.

Consider the engine already has a redline of 8500RPM. To make 300 BHP they would need 10,000RPM at least. I don't think even Lotus will be capable of that. :)

To gain 300BHP normally aspirated, I think the engine would have to be so radically changed, they might as well pick a different engine. A 50+% power increase for an already highly tuned engine would be very challenging...



DLY
 
#12 ·
To add to the rumor, based on talks at the LA show I had, there is a very good relationship b/w Lotus and Toyota Racing Division (TRD). TRD is working on a supercharger for the 1.8 and Lotus is clearly interested/watching. A factory-supplied supercharger should bump the Elise up to around 240 to 250 hp after knocking a few pts off the compression and retuning the ECU. It could go likely higher, but for a street car, its best to keep it on the street and out of the shop.

Keep in mind that the dual oil coolers are currently over-engineered. The extra cooling may come in handy.

This would be a natural product upgrade for 2006
 
#13 ·
Please say it is so. That would give me just enough time to learn how to drive the car while I shave 100lbs or so. If TRD did infact have a super charger in the works it might become a reality. I need all the help I can get to contend with my brother-in-law's Z06.
 
#17 ·
FI and 10krpm actually makes some bit of sense. Fortunately it makes sense in the "superchargers are useless" direction (yeah I like turbos :) ). Put on a moderately sized turbo with a fairly free flowing system and an engine turning at 10krpm will spin it up like nothing. Of course turbo lag down low may be an issue.

Ok lets go back to the bike example again. There are plenty of CURRENT model japanese bike doing the 140hp range in 1l of space. My bike does 108 rear wheel stockwith an engine rating around 114hp, and it is a touring bike! The 999 produces 123hp stock, with a few mods its in the 140hp range.

Remember without any kind of vvti, and retain the huge amounts of torque in 1l twins. Almost doubling the displacement, slightly higher compression ratio, adding in vvti and you should easily be able to double the bikes hp NA. IMO its going to require cam changes, and some random headwork. I dont know what people think about the valves as they currently exist if they restrict airflow or whatever. Maybe they are a major restriction, maybe not. My guess is still that 260 in an exige at 10krpm WITHOUT going for a turbo should be possible for a vvti system with a proper cam setup and some fairly radical valve/head setups. Maybe even up the compression ratio by a small amount. Remember, lotus does have the mechanical ability to scrap the stock head and do up their own, even if that isn't the norm.

Scot
 
#19 ·
The E30 M3 evolution engine had 225 HP but was a Europe only engine as it did not meet US emission specs. The US engine had 192 HP but is a fairly heavy engine as it has a cast iron block. I doubt you could get the HP in the 150 range and still be complient with the regs.
If Lotus wants to supercharge or turbo the Exige to get to the mid 200s that works for me.
 
#20 ·
scot said:
... Almost doubling the displacement, slightly higher compression ratio, adding in vvti and you should easily be able to double the bikes hp NA. ...

Scot
It's difficult to scale up the performance of a smaller engine, given the same configuration. As the displacement scales up, the piston stroke gets longer and peak piston speeds go up. As the piston speed goes up, the forces generated on the rod journals, crank journals and crank main bearings go up geometrically.

The Toyota engine can probably be made to run to 10K RPM, but probably not reliably enough for a factory warranty. The Toyota engine is an undersquare design (stroke is longer than bore diameter) that further exacerbates the high-RPM problem. It also limits the valve size, affecting the ability to breathe freely at high RPM. The undersquare design is better for controlling emissions and provides better low-end torque characteristics.

vvti does not help increase peak HP. It's purpose is to broaden the torque curve so that more torque is produced at points in the RPM range outside the peak. Great for the street. If you deactivated the VVT in the Toyota engine by locking it in high-speed mode, it would not affect the peak HP value. It probably would not be very streetable either...the high-speed cam lobes seem to be very aggressive.
 
#22 ·
Randy,

I heard the same from my guys down under. Rumor has it that the lads in England are trying to get 300HP out of the 1.8 liter Toyota motor with a supercharger, but they are blowing motors left and right at the moment.

The US spec Lotus Exige is expected to hit the US market sometime next year. Expect a price to be well over the $60,000 mark.

This car should be able to beat just about anything on the road if they can pull it off.

Best Wishes,
Mitch
 
#23 ·
300 hp is very ambitious without reducing the compression, reinforcing the cylinder walls, and changing out the valves and springs. If they go all out then you can run a full 1 bar and increase the redline to 9500 rpm. 300HP shouldn't be a problem. I'd sign up in a heart beat. In fact I'll likely go that way regardless I'd just like Lotus to workout the tuning so I can avoid a lot of time on the DYNO. Fortunately I have a local shop with a lot of know if Lotus drops the ball.
 
#24 ·
Even 9500 RPM might be daunting. Take the Honda S2000 engine. Honda claims the 2.0L version has a higher piston speed than Honda's F1 engine!

When they enlarged it to 2.1L by increasing the stroke, they had to cut 500RPM off the redline. So going up 1000 RPM, on a motor that's undersquare, well... where there's a will, there's a way, but it sounds real expensive.

I would think turbocharging would be the way to go, because while it is more complex, there is more freedom in where you can locate components like the turbine. Lotus getting 300BHP from a supercharger would be amazing.

Consider that a Jaguar XJR "only" gets a 100 BHP supercharged boost, from a 4.2L V8 running .8 bar. This is using a M112 supercharger which has a displacement of 112 cu. in. That's a supercharger with a displacement as large as the host Toyota engine itself!

If the "super" Elise/Exige gets rid of the trunk, then there's lots more room for power adding goodies...


DLY
 
#25 ·
It seems like the 2ZZ-GE engine failures that have occurred from a bad downshift were do to valve/spring failures. Apparently there are valve and spring sets that are available in Japan that people are running in the Celica GT-S. They are supposed to be good for 9500RPM. 1K is not such a big jump from the current redline. There are turbo and I believe even a supercharger kit available for the Rover. If you can do it to the Rover then it should be feasable for the Toyota. Push it to the limit Lotus. Lets see an Elise Sport 260 offering in a year or two.