[Coyne]

I live in Phoenix (no lotus dealer anymore), and my second cam still engages at 6200 rpm. I have heard much talk of getting it lowered to a lower rpm threshold. My Elise is fairly bone stock (performance wise), stage 2 exhaust and N/A. My questions are:

1. Does this make the car any faster in actuality?
2. Does this reduce the reliability/ life if the engine in a significant way?
3. I would assume an ECU re flash would be needed, but how would I do this in AZ? (Also, the car is my only DD).
4. LSS wheels; stock or black plasti-dipped?

Thanks for the info, assuming there is any.

 

[cashxdr]

The main reason for lowering the cam switch over on a NA car is so the second cam doesn't kick in in the middle of a corner and so you can stay on second cam longer.

If you are not into high performance driving on twisty roads or tracking the car then just leave it as it is

 

[glb]

Alas, I cannot agree.

1. There is a huge valley right before the cam change. If you eliminate that valley, you will p/u about 20 hp thru those rpms.

2. Smoother to drive. In my case, a bit more tq so I can run around town and some back roads in one higher gear.

3. It will be faster:

http://www.lotustalk.com/forums/f25/pes-chip-experience-37912/

 

[me73]

If your engine has a tendency to wipe the high lift cam, the reason for which is not completely understood from what I can tell, you'll wipe it sooner.

 

[hackish]

I live in Phoenix (no lotus dealer anymore), and my second cam still engages at 6200 rpm. I have heard much talk of getting it lowered to a lower rpm threshold. My Elise is fairly bone stock (performance wise), stage 2 exhaust and N/A. My questions are:

1. Does this make the car any faster in actuality?
2. Does this reduce the reliability/ life if the engine in a significant way?
3. I would assume an ECU re flash would be needed, but how would I do this in AZ? (Also, the car is my only DD).

You should talk to Phil @BOE. He has put probably 100 miles on his dyno with a few NA cars to tweak every last increase out of them.

The old technology used to be mailing your ECU somewhere and having them pry it open to physically solder or program chips. His way of doing it involves just buying a cable and flashing the car in your driveway using any ol windows laptop.

-Michael

 

[cashxdr]

I guess my point is that if you do not drive your car hard all the time, then the stock second cam rush is pretty invigorating.

If you lower the cam point, that feeling goes away

 

[glb]

If your engine has a tendency to wipe the high lift cam, the reason for which is not completely understood from what I can tell, you'll wipe it sooner.

I don't believe that is true. Is this conjecture?

What most ppl don't realize is that even after water temp is up to normal, we must wait an additional 10+ minutes to get on cam.

Noted by a few engine builders here.

 

[glb]

You should talk to Phil @BOE. He has put probably 100 miles on his dyno with a few NA cars to tweak every last increase out of them.

The old technology used to be mailing your ECU somewhere and having them pry it open to physically solder or program chips. His way of doing it involves just buying a cable and flashing the car in your driveway using any ol windows laptop.

-Michael

Phil is who I'd go to today.

 

[glb]

I guess my point is that if you do not drive your car hard all the time, then the stock second cam rush is pretty invigorating.

If you lower the cam point, that feeling goes away

I think "invigorating" was mostly a mktg ploy.

Look, the car is just faster with the lower cam change.

That is much better, right?

 

[cashxdr]

I had forgotten what it was like since I have been supercharged for so long, but when Kim got her car, I had to admit when that second cam comes in and the air box flap opens (desnorkled of course) that it was a really cool rush that I sort of missed.

Maybe its just me

 

[me73]

I don't believe that is true. Is this conjecture?

What most ppl don't realize is that even after water temp is up to normal, we must wait an additional 10+ minutes to get on cam.

Noted by a few engine builders here.

I've not seen any conclusive evidence of the cause of the wiped cams. 10+ minutes of warm up would sound like a good idea, but unless there's an a to b comparison or something similar, warm up time is the conjecture. Please share if I've missed it.

Regardless of the cause, more time on cam in a car that wipes cams=faster wiped cams.

 

[glb]

I've not seen any conclusive evidence of the cause of the wiped cams. 10+ minutes of warm up would sound like a good idea, but unless there's an a to b comparison or something similar, warm up time is the conjecture. Please share if I've missed it.

Regardless of the cause, more time on cam in a car that wipes cams=faster wiped cams.

You'll have to either believe me or do a search. But, it's come up > once, with the pros all saying this.

Oil takes longer to get to oper temp. I blanked off one of my two oil coolers.

Ergo, it makes sense.

Frankly, I'd just do it, looking at risk vs. gain.

Yes, no definitive answer on cam problem. I do have 71k miles w/no issue.

Because there is no answer, not sure how much extra wear (via time) enters into it.

I had forgotten what it was like since I have been supercharged for so long, but when Kim got her car, I had to admit when that second cam comes in and the air box flap opens (desnorkled of course) that it was a really cool rush that I sort of missed.

Maybe its just me

No, it's not just you. Toyota, according to my friend engineer there wanted ppl to feel that rush, i.e. marketing took priority over speed.

 

[Coyne]

I had forgotten what it was like since I have been supercharged for so long, but when Kim got her car, I had to admit when that second cam comes in and the air box flap opens (desnorkled of course) that it was a really cool rush that I sort of missed.

Maybe its just me

Interesting perspectives from everyone. I wasn't aware the second cam was so fragile.

I thought that the second can boost was retained when supercharged? Maybe I misunderstood. It would be a shame to lose that visceral feeling...

 

[andy7777]

The jerk is gone but the fun remains when the switchover is lowered a few hundred RPMs. I used the old Sector 111 tune, which is just a copy of the Lotus Sport version, all it does is lower the switchover. I seriously doubt that it adds any HP. As Darrin said, it is useful on the track so you don't get a sudden mid-corner bump. If I wasn't tracking the car I would have left things as is.

 

[glb]

Interesting perspectives from everyone. I wasn't aware the second cam was so fragile.

I thought that the second can boost was retained when supercharged? Maybe I misunderstood. It would be a shame to lose that visceral feeling...

It's not exactly fragile. Some ppl experienced premature wear, but most engines are OK.

Remember that the visceral feeling is costing you speed.

The jerk is gone but the fun remains when the switchover is lowered a few hundred RPMs. I used the old Sector 111 tune, which is just a copy of the Lotus Sport version, all it does is lower the switchover. I seriously doubt that it adds any HP. As Darrin said, it is useful on the track so you don't get a sudden mid-corner bump. If I wasn't tracking the car I would have left things as is.

I don't know about S111, but read many times that the LS version does not increase HP.

 

[Coyne]

It's not exactly fragile. Some ppl experienced premature wear, but most engines are OK.

Remember that the visceral feeling is costing you speed.



I don't know about S111, but read many times that the LS version does not increase HP.

So, your opinion is that the 2nd can should always be engaged? Or just at a lower rpm?

 

[oldmansan]

So, your opinion is that the 2nd can should always be engaged? Or just at a lower rpm?

Of course not. Each cam has a purpose.

San

 

[me73]

You'll have to either believe me or do a search. But, it's come up > once, with the pros all saying this.

Oil takes longer to get to oper temp. I blanked off one of my two oil coolers.

Ergo, it makes sense.

Frankly, I'd just do it, looking at risk vs. gain.

Yes, no definitive answer on cam problem. I do have 71k miles w/no issue.

Because there is no answer, not sure how much extra wear (via time) enters into it.

Nothing conclusive here

http://www.lotustalk.com/forums/f25...-rocker-arm-breakage-p1302-50594/index19.html

Or here

http://www.lotustalk.com/forums/f25/another-wiped-cam-but-bit-different-63503/index7.html

Or here

http://www.lotustalk.com/forums/f25/bad-camshafts-possible-remedy-54587/index5.html

There's a theory here with no evidence and some opposition

http://www.lotustalk.com/forums/f31...ures-lotus-ecu-does-not-have-high-idle-93807/

Nothing here either

http://www.lotustalk.com/forums/f3/wiped-inlet-cam-again-117079/

So is it lash, driving style, zddp, material hardness, oil feed locations? No answers in any thread I've ever seen. I tend to agree with my buddy Apex that it's lash related, but I haven't seen anything that definitively points to it.

I wish we knew how to prevent it for sure as I'm sure would everyone else.

 

[glb]

I asked my Toyota engineer friend a few yrs ago if Toyota had seen this issue in their cars with this engine.

He checked and reported they did not. Don't know what this means.

OTOH, I saw a 3rd hand report of the problem cited from a maybe Celica website in the last week. (Not reliable info.)

Again, I don't know.

 

[addertooth]

Okay, I will throw in my two cents. Engaging the second cam earlier does not increase the Peak HP, it does increase the HP between 5200-6200 RPMs. This gives you a better area under the curve torque and HP.
As for the Toyota engineer statement; keep in mind the Lotus tune raised the redline slightly on the engine. The Celica, Corolla, Matrix and Pontiac Vibe did not rev as high. I am unaware of anyone wiping a Piper Cam, which is manufactured with a bit harder metal.
Most people who track or autocross dislike the stock tune; the sudden upward bump in torque, if it occurs mid-turn, can unsettle the car (if it is already cornering near 1G).