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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
 

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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?
 

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Hmm, very interesting! Just when I thought all the wild rumors and speculation were over, the Exige nears the horizon... ;)
 

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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
 

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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
 

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Discussion Starter #8
I hear rumors of a supercharger. :)
 

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Exige

Lotus recently annouced, quitely, that the engineering side was working to take turbos to another level (reliability wise). I wonder if there is something to the rumor that a 300 hp yota 4-pot turbo is in the works.
 

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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
 

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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.
 

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Why not 10krpm? 4cyl 4stroke motorcycle engines are in the 14krpm range now at 1l, and my ducati at 996cc is running at 10.5k. The idea of a car at 10k with 1.8l of engine does not seem too far fetched.

Scot
 

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Forced induction and 10k rpm? I don't think so...I swore I read somewhere that a turbo or supercharger is a difficult set-up for the Elise because of space constraints for proper cooling.

I'm all for it happening if they can do it :D
 

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260-300hp? Wow. That'll kick.

Well I hope that they bring it here as well. I'd guess they'll bring the current one over for track-only use. So probably we'll get a street car after they correct the front end DOT issue. Maybe a street Exige in 2006?
 

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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
 

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I'm not a big fan of FI, but would love to see an Exige with that kind of HP.

I would love for Lotus to get the rights to the old BMW M3 4 cyl engine and jam it in there. IF I remember correctly, that engine would put out 227 HP, normally aspirated, and could be tweaked to achieve 250 quite easily.
 

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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.
 

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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.
 
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