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Hi guys. Looks good. If this is something you think can be offered as a package to current Evora owners, I would suggest you contact Bibs as to becoming an Advertiser on here.

 

Has this all been tested on road as yet?

 

I am presuming the third pipe is a blow off valve dump? Unfortunately can't be used in Australia like that as any dump line has to go into the exhaust silencer. I thought that was the rule in US as well?

 

And, silencer?

 

From the little I know in Oz, this may not get past an inspection. I expect others will know a lot more than I do. :)

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Nice numbers - as they are WHP I'm guessing that's about 500BHP at the crank - much more like it for a 3.5L V6 IMHO.

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I would be interested to know what it is like for lag?  Looks like a big turbo some way from the inlet?

 

I cant see all the pics (cross country trains block them)  is there an intercooler?

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Which is amazing considering the length of the pipework... Does your air not compress under pressure to cause lag?

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With forced induction there is always a bit of "lag". With this setup it is very minimal, reaching 5PSI at 2500RPM in 1st-3rd gear and 2,000RPM 4th-6th gear. The Triple Ceramic, oil-less, billet turbo we used is much faster spooling and more technologically advanced than any other aftermarket turbo. The engine displacement, VVTI and higher compression all make for a quicker spool as well. The small amount of intercooler piping and highly efficient air-to-water intercooler has a very low pressure drop as well. We chose this turbo specifically for quicker spool, linear/usable powerband and the ability to run low boost at high efficiency at 400RWHP with the ability to make 5-600RWHP in the future.

The track inspired nature of this car has not been compromised. My main hobby is road-racing, where a linear powerband is much better than a car that makes no power until 6,000 RPM. Take this car to the road course or carve up a back road, you will always be in boost and producing more usable power.

For a reference, look at the stock Evora and Evora S dyno chart curves below. There is more power everywhere in the curve compared to the stock Evora and nearly everywhere compared to the Evora S. The turbo powerband also does not fall off at the top like the Evora and Evora S.

There is no huge blip of power compared to a car running a huge turbo at very high boost, which is what most people associate as undesirable turbo lag for cornering.

Turbo Evora Dyno Chart

vMoIMAX.jpg
Stock NA Evora Dyno Sheet

u6EoAbF.jpg

Evora S with a few mods, Dyno

lJ9M3Ao.jpg

Edited by Meghani Motorsports

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Are there advantages of a turbo over a supercharger?

 

Buddsy

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Is the Evora S not available in USA?

 

Buddsy

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Do my questions not rate a mention or reply? :coffee:

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Turbo's are generally laggy, superchargers rob HP to create HP. Heat sink is an issue with turbo's too...

 

http://www.carthrottle.com/post/engineering-explained-the-pros-and-cons-of-turbochargers-vs-superchargers/

 

Good link, but the type of supercharger also makes a difference.

 

The Evora S and the boosted 2ZZ Elises/Exiges use a positive displacement pump (roots) type supercharger. This just moves a fixed volume of air per rev. It does no compression within the supercharger, and is the least efficient, thermodynamically speaking. All the power used by the supercharger goes into heating the intake air - my 2ZZ uses 20HP - i.e. 15kW to generate 10psi and in doing so heats the charge air by 80-100C !

 

Turbos and centrifugal superchargers (Rotrex) on the other hand compress the air within the turbo/compressor. This is more thermodynamically efficient, so there is less heating of the air at the same boost level. This means you will make more power for the same boost level as cold air is denser and therefore more oxygen rich than hot air at the same pressure.

 

A turbo is laggy because you need more exhaust flow to spin the turbine before you get more compressor speed and more boost. However obviously you don't get more exhaust flow without more air going in the front of the engine...

 

The amount of piping between the throttle and the intake runners does also affect responsiveness, but this can be good or bad in any turbo or supercharger system.

 

Driving wise, a roots-style charger gives you bags of torque at low rpm, but IMHO can feel a little wheezy at the top of the rev-range, as the flow is linear with increasing rpm. Turbos/Rotrex style superchargers have non-linear flow rates, and the airflow seems to 'explode' when you hit their sweet spot. This can make the low-end response a bit pants, only for it to go ballistic when you have 'spooled it up'. Or ofcourse, you can got for a smaller turbo that hits its sweet spot lower down the rev-range, but might run out of puff at the high end.

 

If I had the money, I'd have both - big roots to get me off the line, bypassed at about 4k rpm, and big laggy turbo to take me from 3.5k rpm to infinity and beyond :)

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Or just save the pennies and trade up to an Evora 400 which has been fully tested, mapped and configured for power AND reliability. I'd rather go with Lotus engineering than after-market for something like this as Lotus is a high performance engineering marque with a proven long pedigree so I would trust them to get the whole package (power, handling, stopping) well balanced and correct - unlike of course a mainstream manufacturer who lives for compromise.

 

Just saying.... :2guns:

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Sorry for the late reply.

 

Are there advantages of a turbo over a supercharger?

 

Buddsy

 

Each have their advantages/disadvantages as others have stated. The placement and design of the stock non-intercooled Supercharger produces loads of heat, which after hard driving will produce less horsepower and have a greater potential for detonation. The boost cannot be electronically controlled with the supercharger, which require replacing the pulley. Superchargers tend to lose power at high RPM. The advantage of a supercharger is it produces more power in the lower rpm's. Our setup produces about ~25RWHP less under 3,000RPM, but makes more power and torque everywhere else, even compared to the fully modified Evora S.

 

Hi guys. Looks good. If this is something you think can be offered as a package to current Evora owners, I would suggest you contact Bibs as to becoming an Advertiser on here.

 

Has this all been tested on road as yet?

 

I am presuming the third pipe is a blow off valve dump? Unfortunately can't be used in Australia like that as any dump line has to go into the exhaust silencer. I thought that was the rule in US as well?

 

And, silencer?

 

From the little I know in Oz, this may not get past an inspection. I expect others will know a lot more than I do. :)

 

We've PM'd Bibs, and are looking into becoming a sponsor. The exhaust is fully customizable, we can add an extra high flow catalytic converter or muffler, as well as have the wastegate dump recirculated into the exhaust. The car has catalytic converters in the stock manifolds which allow it to pass emissions here, even with a straight pipe from the turbo. We have about 500 miles on the turbo setup and everything is functioning great. We've taken Two NA Evora owners for test rides and the reaction has been positive, 100% different animal with 400RWHP. The chassis is amazing with the added power, it makes up for where the car lacks. No more passing high horsepower cars in the corners to be passed back on the straights. :)   The Evora S is in the states. We've been talking with an Evora S owner that is interested in Twin charging, to get the advantages of both the supercharger and turbocharger.

Edited by Meghani Motorsports
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I'm with Andy. I'm always amused by the many casual assertions that Hethel engineers haven't got a clue and that all Lotus products are flawed in a way that means they must be "improved".

In truth, I'm sure that positive changes can be made to any set up, whether it be factory or after-market, but the basic product is pretty bloody good. Why do so many feel the need to tinker with their Lotus and claim to improve some aspect of its engineering - something that they probably wouldn't dream of with a Porsche or Audi or Ford.

I suspect that in most cases the outcome is a car that is 'different' but is it really better? How many compromises carefully engineered out during development at the factory are put back in by after market mods...

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As a new Lotus owner I do get the impression that there are a lot of very conservative owners of this marque. If you modify your car you will void warranties and reduce the resale market and therefore the cars value, but that's not to say that there is nothing that could be improved on a stock car.

However good the engineers at Hethel are, all cars are built to a budget and that IMHO implies certain tradeoffs and comprises. 345 BHP from 3.5 litres seems pretty tame to me - but was obviously a number Lotus and Toyota were happy to warranty. Now they seem happy with 400BHP so that suggests to me that the car can be improved with more go!

I don't personally think that going aftermarket denigrates the efforts of the factory's engineers - and BTW there are people who feel the need to slap turbos on V12 Lambos for more go!

I love my Evora but there are definitely things that could make it even better!

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Absolutely right. Every manufacturer is heavily constrained by budget, emissions laws, etc. that all carry tradeoffs with them. Even model strategy plays a role, why else would the (identical) engine in a Cayman GT4 have 10 HP less than in the 911?

 

As an owner I don't care about these constraints, why shouldn't I tap intoe the reserves the car / engine / gearbos, etc. have? By doing it I'm not saying Lotus engineers aren't good enough, in fact I'm sure they could get even more power out of the engine. It just wouldn't be economical for Lotus to do.

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TBD - you are correct and if you desire it you should go as far as you want to exploit the reserves in the engine / gearbox etc.

 

Indeed, I am looking at a new set of headers for my car to release just some of that potential in the reserves. So we kinda agree.

 

I guess though there is a difference between "fettling" to get an extra 10% power which probably keeps the car balanced overall, than a wholesale engineering change to get 40% plus extra power (NA stock 275 versus 400 plus)which will undoubtedly need other things to be looked at like braking (the 400 has larger brakes for instance already), dampers, etc. I have no doubt there are some very fine 3rd party company's out there who could engineer the whole package. But at what price and might it not be better just to move the car on and, for instance, upgrade to the 400.  Just look at the cost of the supercharger upgrade for the NA - £15k - £20K with all bits modified and balanced etc.

 

No right or wrong answer.

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Sorry for the late reply.

 

 

Each have their advantages/disadvantages as others have stated. The placement and design of the stock non-intercooled Supercharger produces loads of heat, which after hard driving will produce less horsepower and have a greater potential for detonation. The boost cannot be electronically controlled with the supercharger, which require replacing the pulley. Superchargers tend to lose power at high RPM. The advantage of a supercharger is it produces more power in the lower rpm's. Our setup produces about ~25RWHP less under 3,000RPM, but makes more power and torque everywhere else, even compared to the fully modified Evora S.

 

 

We've PM'd Bibs, and are looking into becoming a sponsor. The exhaust is fully customizable, we can add an extra high flow catalytic converter or muffler, as well as have the wastegate dump recirculated into the exhaust. The car has catalytic converters in the stock manifolds which allow it to pass emissions here, even with a straight pipe from the turbo. We have about 500 miles on the turbo setup and everything is functioning great. We've taken Two NA Evora owners for test rides and the reaction has been positive, 100% different animal with 400RWHP. The chassis is amazing with the added power, it makes up for where the car lacks. No more passing high horsepower cars in the corners to be passed back on the straights. :)   The Evora S is in the states. We've been talking with an Evora S owner that is interested in Twin charging, to get the advantages of both the supercharger and turbocharger.

You've rightly said the Evora S is lacking a charge cooler and SC performance is constrained by the compressed air temperature. 

 

So, how do you intend to resolve this issue in a compound charged configuration? The charge cooler after the turbo would be in fron of the SC, adding little value. 

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In the end standard cars will hold there value more in the long run so go on add your mods ???

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If you drive it, it will depreciate. If you don't it will still depreciate. If you put 500BHP in it, you're right, it will probably depreciate even faster, but did you buy it for the next owner, or to drive it really fast and grin like an idiot while doing so?

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Implying you can't go fast enough with the stock 350bhp?

 

Lets be honest here. For the people who do all their driving on public roads, is more power really necessary?

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I can go ' fast enough' in my 1L Yaris but that doesn't mean that it has enough power!

It's not all about speed - my S feels a bit wheezy in 6th going up hill - another 100BHP at red line would give me more usable torque at 2000 rpm.

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