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Discussion Starter #1
This is just a generic question of all you guys who have an Evora S [mine is a 2011 with only 13K miles and no other mods than headers] and wants to stay pretty close to the 2017 and later models in h.p. I added a highly renowned set of headers and the car ran great for about 10 miles. After that, it has been a source of frustration, as it runs like crap and gets me between 6 and 9.7 mpg driving daintily. I have cycled it between hot and cold a dozen times, but the computer does choose to learn from the experiences. It sputters black soot and undoubtedly is fouling the plugs.
I expect a professional tune to be sent to me soon, but in the meantime, what can I do to help out when the tune arrives?
1. Change spark plugs?
2. Change coils on each cylinder, or just on the cylinders which are coding?
3. Rub elk grease on the hubcaps? Whatttt???
4. I believe the plug wires are correctly installed, but God only knows. Thanks for your replies and questions. H-E-L-P!
 

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Illegal Alien
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You can get Pre and post Cat O2 sensors flipped, although I would expect this car to be throwing CEL codes. Are O2 extension wires plugged in correctly/fully seated?, vacuum lines knocked off?, air leak at block to manifold flange? or any other air leak between engine black and last O2 sensor? Installing headers without a tune should not in of itself cause issues. What is the renowned brand? have you approached them.
 

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Acme Super Moderator ** The Enforcer **
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It wasn't like a few of us didn't you warn that you might have issues. For those that didn't read the previous thread with details about the headers.


San
 

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Discussion Starter #6
The headers aren't the problem. The O2 sensors, the coil packs, the spark plugs maybe, but not the headers. For instance, We discovered tonight that only half the engine was working as designed. The rear bank, #1, made the headers too hot to touch very more than very very briefly, while the 2nd bank-in front-heated the header up, but you could put your hand on the front pipes and leave them there without burning your hand.

I swapped out the rear O2s and the car ran better, but swapping the front O2s did not improve anything, and probably hurt a little. Either way, the #1 bank (rear) ran hotter and therefore produced more h.p. What does this signify to you Lotus mechanics out there?
 

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Discussion Starter #7
It wasn't like a few of us didn't you warn that you might have issues. For those that didn't read the previous thread with details about the headers.


San
The Swindon headers are not on the car because, although they fit the engine, they do NOT fit the car. No way to get them into the engine compartment and attached to the engine. The rear one fits, but not the front one, bank #2.
 

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Acme Super Moderator ** The Enforcer **
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The Swindon headers are not on the car because, although they fit the engine, they do NOT fit the car. No way to get them into the engine compartment and attached to the engine. The rear one fits, but not the front one, bank #2.
You're looking for help, but you haven't provided any details of what you installed, nor pictures. How would one know that you didn't install the Swindon headers you said you had purchased and were going to install? You've installed some mystery headers and expect that by saying the car runs rough you'll get some meaningful responses. You can't expect an opinion of a painting if you've blindfolded the person you're asking.

San
 

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Discussion Starter #10
You're looking for help, but you haven't provided any details of what you installed, nor pictures. How would one know that you didn't install the Swindon headers you said you had purchased and were going to install? You've installed some mystery headers and expect that by saying the car runs rough you'll get some meaningful responses. You can't expect an opinion of a painting if you've blindfolded the person you're asking.

San
I'm an amateur artist, but less than an amateur mechanic. I can tell you of personal knowledge that Your analogy is dumb. Knowing the brand-and for posters like you-I will not blame the problem on a systemic Lotus Evora electrical problem. Most car makers' cars will run quite well with headers, but Not Evoras. You would do yourself a big favor if you would Study up on the wiring harnesses of Evoras, and learn how crappy the Evora electrical systems actually are. But my posts were not intended to fix blame, though your post blames the person asking for help-which you never did. The true experts know about the wiring harnesses and poor electrical components on these cars, and yes, have learned this from men who are genuinely experts with these cars. So you will never know what brand of headers I use, because the problem is NOT with the headers, but with ANY catless headers mounted on an Evora without a special tune. The tune will work it out. If you have nothing constructive to say, you are wasting my time and the time of others. Constructive criticism can be helpful. Your criticism is NOT.
 

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Discussion Starter #11
So you have installed non stock headers right? Did you install them?

If its running that bad you must be getting some codes. Have you read them?
Yes, I have read them and informed someone who can DO something about the tune. I'm asking here for some suggestions based on what I have shared. My mechanic and I installed them-mostly him. I'm not a mechanic, but I can hand someone tools and help with tightening nuts, bolts, etc. The codes are most misfires and O2 sensor related. The rear header pipes get very hot, but the front header pipes only get slightly hot, which you can touch without removing your fingers or hand. Only half the engine is doing most of the work. The car will only max out at 80 mph; it is in limp mode.
 

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Acme Super Moderator ** The Enforcer **
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I'm an amateur artist, but less than an amateur mechanic. I can tell you of personal knowledge that Your analogy is dumb. Knowing the brand-and for posters like you-I will not blame the problem on a systemic Lotus Evora electrical problem. Most car makers' cars will run quite well with headers, but Not Evoras. You would do yourself a big favor if you would Study up on the wiring harnesses of Evoras, and learn how crappy the Evora electrical systems actually are. But my posts were not intended to fix blame, though your post blames the person asking for help-which you never did. The true experts know about the wiring harnesses and poor electrical components on these cars, and yes, have learned this from men who are genuinely experts with these cars. So you will never know what brand of headers I use, because the problem is NOT with the headers, but with ANY catless headers mounted on an Evora without a special tune. The tune will work it out. If you have nothing constructive to say, you are wasting my time and the time of others. Constructive criticism can be helpful. Your criticism is NOT.
Seriously? You'll take the details of your headers to the grave and that will somehow show all of us how right you are? You're off to a splendid start here. If anyone here is wasting other's time, it is you. Despite that, I wish you luck.

San
 

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How do you know it’s not the headers? Just because other cars can have higher flow headers and not be an issue doesn’t mean this ‘lotus tuned Toyota engine that never came with a supercharger from Toyota that now has aftermarket headers’

You have no idea what their limits are and how close they run to them.

You want help, be open to discussion without getting all butthurt.
 

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Discussion Starter #14
How do you know it’s not the headers? Just because other cars can have higher flow headers and not be an issue doesn’t mean this ‘lotus tuned Toyota engine that never came with a supercharger from Toyota that now has aftermarket headers’

You have no idea what their limits are and how close they run to them.

You want help, be open to discussion without getting all butthurt.
How do you know it’s not the headers? Just because other cars can have higher flow headers and not be an issue doesn’t mean this ‘lotus tuned Toyota engine that never came with a supercharger from Toyota that now has aftermarket headers’

You have no idea what their limits are and how close they run to them.

You want help, be open to discussion without getting all butthurt.
You might want to consider what I have learned from professionals before you climb out onto a limb and tell me I have no idea what I'm talking about. The problem is: it is an Evora. I have owned multiple Lotuses through the years: a 2008 Elise Anniversary s/c, 1990 Esprit SE, 2005 Elise race car with cage, etc, in which I hit 130 mphon the front straight at NOLA Motorsports Park in Avondale, LA. No problem for a NA 1.8 4 banger with a tune and a header.

In fact, someone posted recently on this forum something like, "What happened to our forum?" I do know the answer to that question: the comments of people like you two have to do with attacking the OP for what you perceive to be important, when you haven't spent thousands of bucks and many hours working through GOOD suggestions of people who are trying to help, as requested by OP. You don't know WHAT I know, or how I have learned it. You just want to criticize for the sake of criticizing. That's what happened years ago when I posted on this forum.

Just let me thank those who have made some good suggestions without trying to BLAME me or the manufacturer of the headers. These are high quality headers, and that is NOT an issue. Hence, I don't want to expose the manufacturer to those who like to criticize when they have no clue. For example, someone was a wise guy who called up my post of the Swindon headers, which have never run for a second on my car, and presumed they had a "GOTCHA" MOMENT, but in fact revealed ignorance and a desire to attach the OP. Let me do this:

Would the moderators please remove this entire thread as unproductive for the purpose intended. I don't need a-holes making things worse-which is what this site is consistent in doing.
 

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I'll never understand why people respond to topics without anything positive to add. Let's drop the pretentiousness, this is a Lotus forum, not Jaguar (pronounced Jag-ew-are) ?
I thoroughly enjoyed reading your original post and genuinely laughed @ "elk grease on hubcaps" ?
It seems like there were a few genuine attempts at solutions in the true spirit of the forum. Hopefully one of them is helpful because your question is exactly why I come here- someone wanting and willing to wrench on their car and not giving up when things go a bit sideways. Good luck with the headers!
 

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here's a bit of speculation: in order to meet emission standards, i expect most modern cars to trim fuel based on a catalyst oxygen storage model and the downstream oxygen sensor.

older cars, like the 2005 elise, certainly do not do this. but newer cars with larger power and stricter emission standards need to control the catalysts more tightly.

this means that removing a catalyst between the upstream and downstream oxygen sensors will mess up the feedback loop. I'm assuming that the headers had a catalyst between the oxygen sensors on each bank, and that the spacing between the sensor and catalyst was different on each side (hence, a different model of catalyst oxygen storage on each bank). This would lead to misbehavior different on each bank.

if I'm correct, in order to circumvent this misbehavior, the ecu operating strategy needs adjustment. alternately, if you unplug the downstream oxygen sensors, i expect the ecu will use a failsafe mode and stop trimming fuel based on them. this doesn't mean that the catalyst oxygen storage model would be completely overruled, but the oxygen sensor feedback for oxygen or HC breakthrough would be omitted.

again, this is all speculation, but i think it may explain the behavior you're seeing.
 

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Wow....I could have a field day with this guy but...I am trying to reform my ways ....again.
 
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Discussion Starter #18
here's a bit of speculation: in order to meet emission standards, i expect most modern cars to trim fuel based on a catalyst oxygen storage model and the downstream oxygen sensor.

older cars, like the 2005 elise, certainly do not do this. but newer cars with larger power and stricter emission standards need to control the catalysts more tightly.

this means that removing a catalyst between the upstream and downstream oxygen sensors will mess up the feedback loop. I'm assuming that the headers had a catalyst between the oxygen sensors on each bank, and that the spacing between the sensor and catalyst was different on each side (hence, a different model of catalyst oxygen storage on each bank). This would lead to misbehavior different on each bank.

if I'm correct, in order to circumvent this misbehavior, the ecu operating strategy needs adjustment. alternately, if you unplug the downstream oxygen sensors, i expect the ecu will use a failsafe mode and stop trimming fuel based on them. this doesn't mean that the catalyst oxygen storage model would be completely overruled, but the oxygen sensor feedback for oxygen or HC breakthrough would be omitted.

again, this is all speculation, but i think it may explain the behavior you're seeing.
I'll never understand why people respond to topics without anything positive to add. Let's drop the pretentiousness, this is a Lotus forum, not Jaguar (pronounced Jag-ew-are) ?
I thoroughly enjoyed reading your original post and genuinely laughed @ "elk grease on hubcaps" ?
It seems like there were a few genuine attempts at solutions in the true spirit of the forum. Hopefully one of them is helpful because your question is exactly why I come here- someone wanting and willing to wrench on their car and not giving up when things go a bit sideways. Good luck with the headers!
I'll never understand why people respond to topics without anything positive to add. Let's drop the pretentiousness, this is a Lotus forum, not Jaguar (pronounced Jag-ew-are) ?
I thoroughly enjoyed reading your original post and genuinely laughed @ "elk grease on hubcaps" ?
It seems like there were a few genuine attempts at solutions in the true spirit of the forum. Hopefully one of them is helpful because your question is exactly why I come here- someone wanting and willing to wrench on their car and not giving up when things go a bit sideways. Good luck with the headers!
Thank you, Artful. Your response is refreshing. I appreciate your comments very much. I have learned tons about this car, though I must wait till the tune, etc. arrives to bale me out of my sophomoric efforts to add 50 WHP to a wonderful car.
 

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Illegal Alien
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I'm an amateur artist, but less than an amateur mechanic. I can tell you of personal knowledge that Your analogy is dumb. Knowing the brand-and for posters like you-I will not blame the problem on a systemic Lotus Evora electrical problem. Most car makers' cars will run quite well with headers, but Not Evoras. You would do yourself a big favor if you would Study up on the wiring harnesses of Evoras, and learn how crappy the Evora electrical systems actually are. But my posts were not intended to fix blame, though your post blames the person asking for help-which you never did. The true experts know about the wiring harnesses and poor electrical components on these cars, and yes, have learned this from men who are genuinely experts with these cars. So you will never know what brand of headers I use, because the problem is NOT with the headers, but with ANY catless headers mounted on an Evora without a special tune. The tune will work it out. If you have nothing constructive to say, you are wasting my time and the time of others. Constructive criticism can be helpful. Your criticism is NOT.
1) under what impression are you that Evora's don't run quite well with Headers? We have been running these cars since at least 2012 with a variety of headers(i.e. short tube, long tube, w/ and w/o downstream Cats) w and w/o tunes on the na and sc variants. The car is very responsive to such.

2) you are a self described amateur mechanic ,but know full well to diagnose a problem that only occurred after adding non-named headers that is IS NOT the headers and that A TUNE will FIX it, lol. Before you **** with a tune, I would suggest that you sort out the root cause of your problem.

3) Again I ask you what Codes are you getting? you don't have 1 bank not firing and get no codes.

4) Swindon (aka Lotus Motorsport) headers will fit with some rework, read the last 8 years of performance posts.

5) Since you like the last set of advice, yes these cars along with every FI car since about 1996 run in a feedback loop under normal driving (not under acceleration, at which time engine bases fuel trims on maps). Regardless taking out a Cat is not the issue, positioning the upstream and downstream O2 sensors is; suggested use is the pre cat O2 positioned at collector of each header bank, then both post cat sensors positioned after the Cat in the single pipe.

Closing: Good luck getting helpful support on your magical headers, throwing mystical codes trusting a voodoo tuner to put it all right. Oh and if as you say "The problem is: it is an Evora", then I suggest that you get something else that you can handle.
 

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Maniacal Motorist
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Just to throw this out there: would mismatched fuel injectors cause those symptoms? The hot side running extremely lean?

Not sure how that would even happen.

I am in the middle of the BOE TVS 1900 conversion. As expected, when I started the car without the tune, it seemed very hot. It did have the proper injectors. Maybe it was just the extra power making the heat, rather than a mixture issue.
 
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