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Discussion Starter #1
I was doing a little research concerning Formula one cars and I find it interesting that turbo charged vehicles have usually done particularly well. In fact usually the general rules wind up restricting the amount of boost they car run up to 4 bars (58psi)! I would be very curious to see a strong argument with some good facts against turbo charging our cars, or some opinions of people who actually have turbocharged loti’s.
 

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You're looking for arguments AGAINST turbocharging?

Uh... I guess they would fall under these catagories:

1. Money.
2. Reliability.

If you've got the cash and the knowledge/experience/tools/equipment to really do it right, then I guess go for it.

xtn
 

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Any form of supercharging increases the effective displacement of an engine. Increasing the boost is adding capacity - at a cost of responsiveness usually (turbo lag). The last turbo F1 cars effectively had two throttle positions - on and off! When they were replaced by NA engines with half the power lap times continued to decrease due to the driveability of the NA cars.

Many on here are fond of FI - and Lotus installs its own version too! I must admit to being an NA fan though (just wish I could put a small high reving V8 in my Elise!!!).
 

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I have a turbo Elise and have driven plenty of supercharged Exiges so I have some experience. With proper turbo sizing, lag simply is not an issue. Now that's not to say there aren't issues with cost and reliabilty, but modern, properly sized turbos on this motor give abundant horsepower and low end torque...more than anyone ever needs.
 

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Forced induction reliability is a outcome of tuning. With proper and moderate tuning a FI 2ZZ engine will last, which also means coughing up extra dough for a proper tune. A major benefit of FI for our engines is that we don't have to rev high to get to our powerband. FI is also cheaper in terms of bang for buck when compared to building a high HP N/A 2ZZ engine. With tuning options today, turbo lag can be minimized to the point where it's almost nonexistent.
 

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I was doing a little research concerning Formula one cars and I find it interesting that turbo charged vehicles have usually done particularly well. In fact usually the general rules wind up restricting the amount of boost they car run up to 4 bars (58psi)! I would be very curious to see a strong argument with some good facts against turbo charging our cars, or some opinions of people who actually have turbocharged loti’s.
Are you trying to make an argument for/against turbo charging an elise based on the results of turbo charging an F1 car?

There's absolutely zero correlation between the two, other than the fact that they both have something called a turbo that's fed by exhaust gases. ;)

I've got a supercharger on my Elise. I'm a big fan of the SC over a turbo because of the linear power delivery. I've never driven a turbo that didn't have lag - I suppose they may exist, but I've not experienced them. While I've never driven a turbo-charged Elise, I would imagine that the light weight compounds the rubber-band effect of the turbo.

That said, there's a ton of info in the Forced Induction section of this forum - I'd suggest browsing through that section if you're interested in FI.
 

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Actually I would think the light weight lessens the rubber-band effect. More mass takes more time to accelerate and overcome the inertia. Less weight scoots faster.

The turbo in my Esprit SE (Chargecooled turbo) makes the 2.2L 4 cyl make around 300hp (stock) and I get 25mpg average or 30+mpg on the highway. Yet the 2700lb+ car still accelerates 0-60 in ~4.6-4.8s when needed. The intake temperatures with the chargecooler are actually lower than a NA car at around 5degC above ambient. More power does equal more stresses, but these cars are fairly reliable, most of the problems are due to the low volume build nature and not the turbo...

Small displacement engines with turbo are a great way to get power and economy. The only downside is that a boosted engine usually runs low compression and kinda sucks at off boost slow driving.

But a turbo engine has to be built right.
Lotus did a great job with the Esprit SE.
It has;
Chargecooling.
forged pistons.
forged aluminum cylinders with nikasil coating.
sodium filled exhaust valves to remove heat faster.
silicon-bronze valve guides for the same reason.
2 secondary injectors for extra fuel to lower temperatures and selectively richen the mixture.

All these things go a long way toward helping an engine cope with the extra heat and pressure from the turbo.
 

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Discussion Starter #10
Are you trying to make an argument for/against turbo charging an elise based on the results of turbo charging an F1 car?

There's absolutely zero correlation between the two, other than the fact that they both have something called a turbo that's fed by exhaust gases. ;)

I've got a supercharger on my Elise. I'm a big fan of the SC over a turbo because of the linear power delivery. I've never driven a turbo that didn't have lag - I suppose they may exist, but I've not experienced them. While I've never driven a turbo-charged Elise, I would imagine that the light weight compounds the rubber-band effect of the turbo.

That said, there's a ton of info in the Forced Induction section of this forum - I'd suggest browsing through that section if you're interested in FI.
Well the something called a turbo that's fed by exhaust gases, will still have to spool up, and that’s the correlation I am talking about.

I've read allot of post in the FI archives, some old some new I just wanted to see peoples takes on the subject. Plus from what I can tell there defiantly more supercharged than turbocharged Elise’s, so some of the information is limited. So I was looking for maybe some newer opinions, could still be the same just a discussion.

I'm personally weighing my options between supercharging and turbo charging. The only real drawback I can see in supercharging is the lower max horsepower.
 

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The reason you see more SC than turbo is simply the price...and the linear power delivery which suits these cars well for track use.

SC setups are capable of 300whp+ and soon probably significantly more.

You have to remember that any more power than that and you have to worry about your engine mounts and your tranny. The chassis of these cars was not designed for that much power.
 

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Tranny in the Lotus will hold up to 550 hp fine. Its the same tranny as in the Celica and MWR didn't explode their stock one till around 650 hp. But yes, I would worry about the mounts in the Lotus, im not sure how strong those are.

Also, there are two main factors between SC & Turbo. Obvious one is how they work, but the other isn't as widely known. If both a SC & turbo are set to give the same amount of PSI into an engine, the turbo will make more power off the same PSI and make it a lot sooner. SC with a 10 PSI pulley only make 10 PSI at the max RPM, its liner in how much PSI it gives by engine speed since the engine runs the pulley. In a turbo, the max PSI can kick in at as low as 3500 rpm (maybe even lower with correct turbo size and tuning). Also, turbos will always provide more torque since they aren't feeding off the engine to make power.
 

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Tranny in the Lotus will hold up to 550 hp fine. Its the same tranny as in the Celica and MWR didn't explode their stock one till around 650 hp. But yes, I would worry about the mounts in the Lotus, im not sure how strong those are.
I also know of others that have started have problem when they hit ~340whp. when driven on track and shifting hard the lotus will put more of a shock on the transmission being rwd than the celicas.
 

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The reason you see more SC than turbo is simply the price...and the linear power delivery which suits these cars well for track use.

SC setups are capable of 300whp+ and soon probably significantly more.

You have to remember that any more power than that and you have to worry about your engine mounts and your tranny. The chassis of these cars was not designed for that much power.
Just to add to this comment, another reason you see more SCs than turbos is b/c ForcedFed has stopped taking orders for their kits and there are more SC manufacturers in the Lotus market. There are a few non-ForcedFed turbos around but not many, and none that are as widely used and tested. It's a demand issue - more people preferred the bang for buck and ease of install of the SCs, so the turbo market pretty much went south.

SCs can produce over 300whp but their torque generally is lacking compared to turbo setups. The flipside is that their power delivery is generally more linear. Not having driven a SC Lotus, I can only speak from my experience with a turbo Elise, and since the car has been wonderfully tuned, power delivery is very smooth and very close to linear. Bang for buck though, the SCs have me well beat.
 

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F1 turbo engines were very small, displacement-regulated engines running turbos larger than those found on most diesel trucks. They had an on/off throttle and huge lag because all anyone cared about was the top ~4,000 revs of the powerband.

They also ran nearly straight toluene and needed fuel heaters to get the things going. Absolutely no comparison to a properly designed street (or even track) turbo system.

With an appropriately sized turbo on a four banger, you should have very little or no lag, and a power band that only improves over the stock one. The only real disadvantages are heat, both in the oil and ambient, but both can be dealt with easily enough.

Personally, I find most NA engines boring as hell, but, that probably has a lot to do with most of my cars being FI. :)
 

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I am a big fan of high revving NA engines. But I simply wanted more power for the Elise so I went with the BWR sc. Now maybe it's the PES chip tuning, but there is definitely a noticible lag getting on throttle at lower RPMs that bothers me. I don't have a lot of experience with FI so maybe this is just to be expected. Don't get me wrong, once you are on boost and keep it there the engine is very responsive and predictable and I love the added power. But it's just that initial tip-in where there is a slight pause, and then the power comes on in a rush. I was going to contact PES and see if they had an updated map the eliminates or reduces this.
 

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Discussion Starter #18
They also ran nearly straight toluene and needed fuel heaters to get the things going. Absolutely no comparison to a properly designed street (or even track) turbo system.
I just never really looked into what formula one cars used for a power plant setup and found it interesting that turbo charging F1 cars was popular. And even as you stated they did have considerable lag so that was something found to be worth dealing with. I know the two setups can be very different but at the heart of things there both pretty simple devices and fundamentally the same. You can change the fuel, valve train, operational speeds but in the end it is still just an IC engine. Now granted when you talk about the material science in engine construction or the dimensional tolerances of components they get extremely different and your right it’s not really worth comparing them except to point out the extremes, but I was looking at a real basic comparison.

Now what’s really interesting is if the areas that have large differences (rpm bandwidth, fuel, ect.) are designed to overcome the lag! And if that’s the case then those are advantages we can’t take advantage of, or at least not on my paycheck.
 

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SCs can produce over 300whp but their torque generally is lacking compared to turbo setups.
HUH?!? :confused:

I lived for ten years with an Esprit Turbo and now have a Katana with the standard pulley on my Elise.

The TE was very well-designed and still had noticeable turbo lag, albeit something that could be accomodated and even used to advantage on the track. But torque was a major weakness. I know many more modern turbo installations are sized and designed to overcome turbo lag, but torque is still poor.

The Katana probably has an 8-10 HP parasitic drag but that is overcome just above idle and the torque difference from the NA engine is still surprising me every time I pull off the line. The linear power delivery and nearly flat torque curve make the SC a delight to drive.

I've found that I'm less inclined to downshift or drive in a lower gear to keep revs up. I can mash the throttle in 6th gear at 60 MPH and I'm touching 90 in 5.5 seconds. Try that in your turbo.

Yes, the ECU can be programmed to make a turbo installation perform far better than just a few years ago, but torque in a small-displacement engine requires brake mean effective pressures in the cylinder that a turbo just doesn't provide at lower revs. And don't forget that turbos also choke the exhaust stream to make the turbo spin, and when there's no boost at low end, it drags the engine down with the backpressure.

Now that I've lived with both, I'm sold on the SC -- for my money, anyway.:up:
 

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HUH?!? :confused:

I lived for ten years with an Esprit Turbo and now have a Katana with the standard pulley on my Elise.

The TE was very well-designed and still had noticeable turbo lag, albeit something that could be accomodated and even used to advantage on the track. But torque was a major weakness. I know many more modern turbo installations are sized and designed to overcome turbo lag, but torque is still poor.

The Katana probably has an 8-10 HP parasitic drag but that is overcome just above idle and the torque difference from the NA engine is still surprising me every time I pull off the line. The linear power delivery and nearly flat torque curve make the SC a delight to drive.

I've found that I'm less inclined to downshift or drive in a lower gear to keep revs up. I can mash the throttle in 6th gear at 60 MPH and I'm touching 90 in 5.5 seconds. Try that in your turbo.

Yes, the ECU can be programmed to make a turbo installation perform far better than just a few years ago, but torque in a small-displacement engine requires brake mean effective pressures in the cylinder that a turbo just doesn't provide at lower revs. And don't forget that turbos also choke the exhaust stream to make the turbo spin, and when there's no boost at low end, it drags the engine down with the backpressure.

Now that I've lived with both, I'm sold on the SC -- for my money, anyway.:up:
In a word, incorrect.

I have 186 lbs/ft torque with 91 octane gas and 220 lb/ft (at 4,000 RPM, no less) on 100 octane gas. Turbos are an excellent way of making torque.
 
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