A&Q about Lotus
Q:
(posted in the main section, as it is not really a discussion of FI, but rather general take on the car, after FI is installed. Ofc it would also be better of in this section, since i want as much opinions as possible and much more people visit this section)
So, im pretty much decided to go down forced induction route...
Many reasons why, but mainly to add some torque and daily drivabiliy as well as having more fun between the corners. Ofc improving lap results is good, but driver training is where the priority is for the time.
Remember, my car is a daily driver and sees a lot of track.
I narrowed my choice down to two kits, lets say for simplicity that both will cost me around $9k (~£5k) + clutch + lsd + accusump + installation.
The kits are:
Forcedfed 275 turbo
Komo-tec 250S supercharger
Added weight is about the same, maybe ff is a bit lighter, but nothing significant.
Peformance as tested by independant magazines:
Turbo:
275 bhp @ 7 psi
200 lb.ft
0-60 4.2
0-100 9.0
1/4 mile 12.3
Supercharger:
260 bhp @ 6 psi
185 lb.ft
0-60 4.2
0-100 9.5
1/4 mile 12.5
Im am heavily leaning towards Komo-tec kit. Why:
1. Reliability is one of my main concerns. Komo-tec uses water cooling and runs lower boost. Also as far as i understand, getting turbo tuned correctly is a lot harder and more importaint.
2. Supercharger power delivery is a slight preference for me, its no big deal at 6-7 psi, but im more of a n/a or s/c guy. I aslo think s/c suits the car a lot better.
3. Peformance difference is the only turbo advantage, but its really not that significant, and i will readily sacrifice a slightly better 0-100 for improved reliability and durability.
What do you guys think?
A:
I agree with most of your points. I think both are roughly equally reliable. My concern would be if something should start to go wrong, it's so difficult to visually inspect that such instances are overlooked until they become too late.
IMHO, I think water cooling is undesirable. You put more heat load into an already loaded system. Does the Komo-tec add an addtional radiator? Does it ever get hot in Russia? Of course, it might be just dandy for winter.
On the other hand, Komo-tec is located much closer than ForcedFed.
You should probably add the Tripoint supercharger to your short list. From the posts so far, it seems to be plug and play. Although i don't think an Elise intercooler is currently available.
A:
It certainly helps that komo-tec is much closer. They also have a guy there who speaks russian, and since my dealer doesnt speak english this should be a great help during instalation and if something goes wrong.
Originally Posted by JnC
IMHO, I think water cooling is undesirable. You put more heat load into an already loaded system. Does the Komo-tec add an addtional radiator? Does it ever get hot in Russia? Of course, it might be just dandy for winter.
this is very interesting, im not sure i quite follow your logic.
As far as i understand, charge cooler is more compact, more efficient and dissipates heat at a much higher rate then standart intercooler. The drawback is increased complexity and slightly higher weight. Please, correct me if im missing something
Komo-tec puts additional radiator in the front iirc.
Moscow summer is 80-90 F, sometimes as high as 100. So, on many summer days its definately quite hot and after successive runs cars like 240R start to struggle with thier air intercoolers and loose some power.
"Tripoint doesnt have an intercooler". Again, as far as i understand, its pretty much pointless to have FI without a good intercooler. Power will drop rapidly, operating temperature will rise and general effect on durability is pretty bad.
A:
Man, I am Jonesing for some more HP. Gonna take the Elise in to work tomorrow.
Nice cool weather here in Florida!
A:
Originally Posted by Val
getting turbo tuned correctly is a lot harder and more importaint.
As far as your engine is concerned, boost is boost. The tuning process is going to be the same. If you want to run the FF kit at a lower boost level for reliability reasons, it's easy enough to add a boost controller or change the wastegate spring setting (depending on how FF sets it up).
Also, FF's intercooler setup looks pretty nifty, I wouldn't count that against them. If you put a turbo on an Elise you will not be disappointed by power delivery. It will be stronger everywhere on the tach.
A:
I'll take a stab at it. I'm "guessing" that tuning might be a bit easier with the supercharger. It's belt driven and repeatable every time as you cycle it since it's mechanically driven. The turbo might vary, especially is you're on or off the throttle. The front heat exchanger with the komo tec may be a good deal, assuming you don't deprive the radiator cooling the engine of air. One thing I'm interested in knowing, how much horsepower does it take to run the supercharger? You may want to ask them that question. Maybe it's 10, maybe much more. You have to factor that in for the total power made to produce the net hp you want. They reflash the ecu if I'm not mistaken. That leaves you in the cold as a self tuner. You may want to keep a spare ecu for reversing your mods if needed. Ask if they're willing to reflash if you need adjusting.
Re: Forcedfed. I've talked to them a time or 2. They seem to strive to upgrade the tuning issues with the unichip. Plug and play is nice for an '05. Mines '06 however, so I cut wires. The turbo is readily available, the supercharger may not be. You likely can play with the unichip yourself if inclined. Invest in a wideband O2 that you can log from. Get a gauge in your car so you can monitor. If you fing the unichip isn't as great as hoped, there's the Xede and Hydra, both kind of new to us.
While you're considering spending some fairly serious money, get 4 stainless thermocouple bungs welded in for the turbo headers. Shouldn't cost much at all. You can plug them, but they're their for use if needed. And while you're at it, make up some aluminum ones for the intercooler. You want to know how hot that furnace air is when it goes into the engine.
Question: what is Komo supplying for the header?
A:
Turbocharging, when done properly, is easier on your engine and a more efficient way of making more power than supercharging. I've argued many times, and I'll argue again:
The only reason Turbocharging has a reputation for unreliability is that with a turbo install, its very easy to get greedy.
m am heavily leaning towards Komo-tec kit. Why:
1. Reliability is one of my main concerns. Komo-tec uses water cooling and runs lower boost. Also as far as i understand, getting turbo tuned correctly is a lot harder and more importaint.
No, not true. Lower boost is not the only issue - superchargers add load to the engine and heat intake air more than turbochargers do. So for a given amount of boost, Supercharging is harder on the motor than turbocharging. I'd call this one a draw, perhaps favoring the turbo a bit, if anything.
Tuning a turbo car is not necessarily more difficult. Since you traditionally run conservative camshafts on a turbo, and you tune speed-density, its actually easier to tune from scratch. People think its harder based on a couple points. The first is that many conversions use either a boost-comp or rescaled MAF system to determine fueling from boost. This is a compromise at best. The second reason is that turbochargers on average run much more boost than superchargers, so you start dealing with intake temps, spool up, anti-lag... all sorts of things that you would also have to deal with if you were running 22psi superchargers.
2. Supercharger power delivery is a slight preference for me, its no big deal at 6-7 psi, but im more of a n/a or s/c guy. I aslo think s/c suits the car a lot better.
With 8psi and a good quality ball-bearing turbo, lag is not an issue. And as far as suiting the car, the ones I've done suit the car very well.
3. Peformance difference is the only turbo advantage, but its really not that significant, and i will readily sacrifice a slightly better 0-100 for improved reliability and durability.
I'm not anti-supercharging at all. I've tuned many amazing supercharged cars, and its never a bad idea. But given the choice, I'd go turbocharging. One BIG reason why so many people go supercharging is its much easier to package. This is one big reason for so many OEM superchargers.
A:
Curious why you ruled out the Bemani Supercharger; it is much more sorted out than Komo-tec.
A:
Originally Posted by MikeW
One thing I'm interested in knowing, how much horsepower does it take to run the supercharger?
They say 80% efficiency. Which i assume is about 12-13 hp at peak power.
Originally Posted by apex speed tech
Lower boost is not the only issue - superchargers add load to the engine and heat intake air more than turbochargers do. So for a given amount of boost, Supercharging is harder on the motor than turbocharging. I'd call this one a draw, perhaps favoring the turbo a bit, if anything.
Indeed, this is what i dont like about superchargers.
Yep, it does eat some hp, but im not sure "harder on the engine for given boost". Maybe s/c has lower hp for given boost or harder on the engine, given same hp is what you mean?
The temperature is why im so comfortable with komotec - 20C, i.e. 60C difference between/after intercooler.
The other reason i am doubtful about forcedfed is that thier cars have not done any extensive milage while supercharged cars from bemani have been going strong for almost 2 years with apparently 0 problems. And kmotec is conceptually even more conservative them bemani.
Originally Posted by apex speed tech
Tuning a turbo car is not necessarily more difficult. Since you traditionally run conservative camshafts on a turbo, and you tune speed-density, its actually easier to tune from scratch.
Maybe i wasnt clear enough here. What i mean is doing a local tune after the manufacturer.
Basically what scares me a bit is this: i was told that forcedfed will definately need a loccal tune after installation has been done. However it seems that superchargers are fine with stock tune.
I dont really want to give my Lotus to a local "turbo shop" to do a "tune" Though i am sure there are knowledgeble people in Moscow, im just not 100% sure where to find them. Basically, its a bit risky.
Originally Posted by sleepless
Curious why you ruled out the Bemani Supercharger; it is much more sorted out than Komo-tec.
Komo-tec is a little more conservative and daily-driver friendly setup using as much stock components as possible. A better chargecooler solution as well.
Ive spoke to people who have driven it on track, and they all say its a fabolous and glitch-free car. Basically its just an iteration of bemani, just in a little bit different way.
The main reason though is in delivering the car. Basically i managed to figure out a deal to get the car to germany real fast and real cheap. So Bemani becomes an automatic no
A:
Yep, it does eat some hp, but im not sure "harder on the engine for given boost". Maybe s/c has lower hp for given boost or harder on the engine, given same hp is what you mean?
What I mean is that if you have a car that's boosted to 6psi, the supercharged one will make less horsepower, and all other things being equal, present a harder strain on the motor due to its drive losses and the higher intake temps due to the inefficiencies of the compressor. By compressor inefficiencies, I'm talking about the fact that the supercharger will heat the intake air more, becuase it has to move the same volume of air with a much slower compressor speed.
The temperature is why im so comfortable with komotec - 20C, i.e. 60C difference between/after intercooler.
If you used the same intercooler with the turbo, you'll see even lower temps. But yes, air/water intercooling does help with the superchargers inherit inefficiency.
Basically what scares me a bit is this: i was told that forcedfed will definately need a loccal tune after installation has been done. However it seems that superchargers are fine with stock tune.
I dont really want to give my Lotus to a local "turbo shop" to do a "tune" Though i am sure there are knowledgeble people in Moscow, im just not 100% sure where to find them. Basically, its a bit risky.
There's no inherit reason why a turbo car would need any more tuning than a supercharged car. There's no reason why a supercharger will be fine with a stock tune and a turbocharger would not. My guess is that you are being led to this conclusion by people comparing hi-boost turbo kits to low boost supercharger kits.
This of it this way: Your engine management system doesn't know the difference between 6psi boost, whether it comes from the turbocharger or supercharger. There is more load with the supercharger, so basically tuning the supercharged car is like tuning the turbo car - except its towing a trailer. So if there was any difference in tuning difficulty, the supercharger should be more difficult. If there is any re-tuning involved, its because either the supercharged maps are really well developed or the turbo maps are not. A properly tuned engine should self-compensate, especially a forced induction motor.
Just some background, I tune engines for a living. I'm on the dyno 3-5 days a week, and always at customer locations. This week I'll do a BMW on a chassis dyno, AMA 600fx bikes at the track, then fly to Dubai to do 2 turbocharged and 2 supercharged offshore powerboat engines. The conclusions I have drawn are from quite a bit of personal experience. That's not to say others haven't had different experiences.
A:
Apex, thats a great insight! really appreciate your help
So, basically would you rather go for a supercharger with a nicely remapped ecu, or a turbo with piggy back which might have some minor issues (eg rough idling)?
A:
One issue that no one has bought up is drivability. The torque characteristics of a turbo vs. a S/C are quite different. A S/C tends to ramp up in a very linear way. Whereas a turbo tends to deliver a big lump of torque in a very short space of time - this gives a turbo engined car more of a wow factor. However in a lightweight package like the Elise it definitely makes the car more of a handful to drive since there is relatively little mass to damper the surge of torque. I would expect a S/C car making similar power to be quicker around a track than a turbo in the hands of a 'typical' driver.
And yes I have driven in anger both turbo and S/C variants of the Elise (S1's with Audi and Honda S/C engine conversions).
A:
Wow this is a lot of info keep it comming.
But i have a question. What about for some guys which want to have the extra power and have the money to put into the car but dont know Sh*t about turbos and s/c or motor for that matter. Like say someone like me. Dont have an elise yet but once i have one i know ima want more power but which would you guys recommend for someone like me. whos just looking to put in the money and get back a faster car . ofcorse im looking for something thats not gonna bite my wallat in the ass after a while. so reliable is what im looking for.
A:
Val
I think you'll find the Forcedfed programming is likely ok as is but leaves a little hp on the table if you want to tune further. It's a bit of a safety factor with the a/f. I talked to John about specific a/f numbers but never got a definite number.
That said, what fuel you run where you lve could be quite different from the US variations.
A:
Originally Posted by HeartxLeSSx
Wow this is a lot of info keep it comming.
But i have a question. What about for some guys which want to have the extra power and have the money to put into the car but dont know Sh*t about turbos and s/c or motor for that matter. Like say someone like me. Dont have an elise yet but once i have one i know ima want more power but which would you guys recommend for someone like me. whos just looking to put in the money and get back a faster car . ofcorse im looking for something thats not gonna bite my wallat in the ass after a while. so reliable is what im looking for.
I think, today, in the US, you have two obvious answers:
1. Exige S
2. ForcedFed 275
A year from now you may have three or four more solid choices. I picked the ForcedFed 275 because it has been around for over a year, there are a lot of them around with a fair number of miles on some of them. Their quality seems to be very good and very consistent. Not that there may not be other good alternatives out there today, but IMHO there aren't enough of them installed and they haven't been around long enough to have a proven track record (no pun intended).
A:
Go turbo - I don't regret it one bit. Absolutely best mod I've done. Make sure you have a reputable installer and just as important if not more, a knowledgable and experienced tuner. I have a Hass turbo and everyone talks about an unstable tune. NOT SO if your tuner knows what he / she is doing. Not only is my tune stable using the eManage ultimate but it also passes state inspection unlike HYDRA (may not be a concern for you but just showing you what is possible if tuned correctly). My vote is for the turbo because of my personal experience with it.
A:
This whole conversation is giving me a horsepower woody.
I know...TMI
A:
Kind of related.
How many of you who have a turbo or SC have also installed a LSD?
A:
Val
Something just went off in my head. I remember when someone (maybe me) came up with the Komo tec sight months ago. I emailed them about whether the blower was a Rotrex and if they refashed the ecu and if they could do an '06. The email I got back from them was vague, implying they weren't going to divulge any information. I surmised it was a Rotrex blower, something I was studying a bit at the time. Heat wise, they're likely cooler than an Eaton, at least an Eaton non-whipple style. Did you get any info from them as far as the blower and if they reflash the '06?
A:
They indeed modify ecu and blower they use is lysholm
All info is on thier web now: