TRUTH/MYTH OF LOTUS ECU

[GTsRasta]

After watching jlitman and dustylax get ran off for trying to offer some headers here, I thought I'd just make another Lotus ECU thread to flesh out the "truths" and the "myths" once and for all. I find it rediculous that dynos and written testimonials with sustained power get thrown out the window for the "un-learning" explanation to be the end-all truth for the Lotus ECU. It's true that mods can contribute to lower power, but it can't be true for all mods. And if it's not true for all mods, isn't the "un-learning" ECU myth therefore debunked by proper mod designs? My arguement can be seen here:

A) Intakes-

This thread has the most recent insight to the "learning" process, and also has Randy Chase's input on intakes in post #21:

How does ECU unlearn mods?

Originally Posted by Randy Chase

According to the first tuner, in his words, the intakes seem to develop more hp initially because they increase airflow and the engine runs lean for some time until the ECU detects the increased airflow via the MAF and tries to compensate. But it does not compensate in a very linear fashion. As I understand it, it adjusts the air/fuel maps. But I was told that my car, after running a CAI on it, had the trims all screwed up. And I was told that this was not uncommon and this tuner found that many cars running aftermarket CAIs will have lost power after a couple weeks. But most owners use butt dynos and the cars sound louder... so they would not notice. It "seems" faster.

He also said that many of these CAIs could cause some negative impacts to long term engine reliability because of the engine running lean at times.

Frankly, I was not that concerned and kept my CAI on because I liked the sound.

Later on in an attempt to really wring out some power, we put my car on the dyno for many weeks testing many parts and combinations. We tested some other intakes and found one that lost something like 15hp. At no time did we find an intake that dynoed over a stock configuration.

We talked to a couple engineers at Lotus and they seemed to confirm this. They felt that the stock intake was optimum for the ECU... assuming no other mods. I can't say too much, but I have seen the stage 3 intake and this intake also seems inline with this thinking.

We tested the green filter and it seemed to give us a little bump, so we ran that, along with removing the snorkle. But a couple hp one way or the other often is the "noise level" on a dyno and not too much should be taken from that.. all in my humble opinion.

So basically what Mr. Chase is saying is that the $240.00 you spent on your Fujita Intake for your stock Lotus from Sector 111 will turn this dyno from their site:



...back to stock over time, assuming you don't have any other mods to your car...great way to spend $240.00 for something that only sounds better. Now here's two dynos, one with an Exige motorworks race header, and the 2nd one with the race hader and the intake:

Exige Motorwerks Dyno Session & Group buy

Race Header:


Race Header + Intake:


Will those obvious peak hp/torque gains be unlearned as well? Take note that low-midrange torque is lost...which is the TRADEOFF for running a mod that caters to a particular rpm range (just like the top end oriented Injen CAI versus the low-midrange oriented AEM CAI for the Celica GTS)...

Based on those results, I honestly can't tell if a guy like the one who did those dynos is throwing away his money or not with those mods... .

B) Headers-

Again, we have Mr. Chase, dynos, and testimonials that have proven to show that headers have gained and SUSTAINED their power adding:

Originally Posted by Randy Chase

On the other end, is the exhaust stuff. I never thought that the ECU did "learning" from this end. Way back, I was told by Lotus engineers to tread very carefully here. They had done a lot of development to max out the header and changing it could have some negative aspects. I figured for the most part that they had a vested interest in saying that. We tried a 4-1 header and the tuner reported we did gain some topend, but had loss in the midrange. Exactly what I did not want. Though for someone else, that might be fine. I was looking for midrange.

We found that the stock header, with some porting, seemed to work pretty well.

That's funny...a 4-1 header design like the Celica GTS PPE and the current Lotus PPE one being designed are top end biased...and the Celica GTS 4-2-1 Weapon R race hader and the forcedfed 4-2-1 Lotus race header are midrange biased as well...hmmm. At least we know now that a properly designed header WILL make power on a Lotus ECU. Moving on with some dynos and testimonials:

1) http://www.elisetalk.com/forums/show...61&postcount=7

Originally Posted by raygr

Before and After FF Street Headers and Cat. Both graphs also include Larini exhaust and Reverie intake.

It was the same day on both dyno runs. I only drove about 10 mins after the headers were installed. I dyno tested it a month later too, and the gains were the same.

2) http://www.elisetalk.com/forums/show...6&postcount=12

Originally Posted by darkSol

Dynoed two hours ago...

I have the exact same numbers as Ray (+/- 0.1)!



Stock vs. TurboXS intake vs. TurboXS + ForcedFed street header + decat + 6" 2bular exhaust

Ugh. 1200 miles. 49 days since header/decat/exhaust install (lots of time for ECU correction).

Look at the silly stock ECU's air-fuel correction numbers... sigh.



At no time does the air-fuel approach 13.2 (which has always made the most power for my normally-aspirated cars)

Oh well... I was wanting 180whp / 130 wtor.

Time for a supercharger

3) Test Car for 2ZZ Race HEader

Originally Posted by MikeW

Jlitman, the concept that the ecu "unlearns" mods is a bit of a sticky wicket.
I try to keep an open mind about things. I also retain a healthy amount of skepticism. There has been a strong feeling that the ecu will wipe out any power gains achieved by mods after a short amount of time. I read this continuously. Others read it too and repeat it until it appears to many people here be the gospel truth. I personally have seen nothing scientific to support this, so I'm not on the bandwagon. Had there been numerous before/after dyno tests showing a change in A/F ratio and power loss, that would be a start. Some people have added a cold air induction and claimed that they didn't see any power gain when they dynoed the car some time down the road. It made a lot of noise and the advertiser claimed 10 more horsepower, right? Therefore, the ecu must have taken that away. Well, that makes me believe there wasn't much of any gain in the first place. A lot of the "ecu unlearing" theory seems to stem from this. Small gains of a couple horsepower are hard to verify with accuracy and repeatability on a Dynojet. Most of the modification people perform are basic cold air, mufflers, and catalytic converter removal. All give very small gains if any at all. Yet they are claimed to product definite power increases. Here, I'm skeptical. The Lotus exhaust, for example, certainly doesn't appear restrictive for an engine with about 200 hp or a little better. No one has ever measured it for backpressure. Here again, If you believe getting rid of a decent exhaust and replacing it with one that's shiny and noisy will give you power, I think it's all psychological. Dyno the car later and it doesn't show anything? The ecu must have taken it away. On the other hand, my car has a FF race header and had plenty of time to cancel out any gain before the dyno. It showed 177 at the wheels. The average stocker has 165. If the ecu always unlearns all mods, I guess I'm the exception.

I think it's safe to say a properly engineered header will make power in a certain rpm range it decides to focus on...

C) Exhaust-

There's no point to argue about this, considering Lotus offers a Stage II exhaust themselves. Mr. Chase says it himself:

Originally Posted by Randy Chase

We later tested a couple of "sport cats" and exhausts and found some nice gains from those. I do not expect those to lose any power from some "learning" aspect of the ECU.

So in conclusion...

1) Where is the power lost for properly engineered mods?
2) Beyond intakes having to deal with unlearning for emission fuel trims, does the Lotus ECU really NOT make more power after improving VE from the header-back?

I'm really trying to understand why you guys hop on power adders from certain vendors one minute (Forcedfed, Sector111, Bane) and expect to get power, and then bash other vendors with all of this "un-learning" nonesense the next minute (dustylax, jlitman, etc). Please help me out in trying to understand why this site seems to act so backwards sometimes...

[Randy Chase]

I don't think it is this site.

I will add. I don't sell headers or intakes and have no agendas or vested interests. There has easily been thousands and thousands of dollars spent on dynos on my car, testing all kinds of combinations, trying to get as much horsepower or torque as I could. I have talked directly with a number of tuners and also with engineers from Lotus.

So... with that said... whatever.

[GTsRasta]

I don't have an agenda either, and I'm not affiliated with any of the vendors here at all, so I don't stand to make/lose anything from my discussions.

The intake arguement I'll accept, but I'm trying to flesh out the header part.

[Chili Red]

Mythbusters has an episode on the Lotus ECU in a few weeks. Make sure not to miss that episode as it will answer all your questions.

[Randy Chase]

Originally Posted by GTsRasta

I don't have an agenda either, and I'm not affiliated with any of the vendors here at all, so I don't stand to make/lose anything from my discussions.

The intake arguement I'll accept, but I'm trying to flesh out the header part.

OK, but let me suggest that it appears you do have an agenda... you seem more emotionally invested in solutions from newcelica or known non-Lotus specific vendors. Appears that way. Now, I could be wrong. You could spend a lot of time on newcelica pushing Lotus specific solutions?

Beyond that, I do respect your intent on this thread. As I said, we did have some gains with one header, but at a loss of midrange and I am now running a different header that seems to work well with the SC and my intake and ECU.

[Dave]

Originally Posted by Chili Red

Mythbusters has an episode on the Lotus ECU in a few weeks. Make sure not to miss that episode as it will answer all your questions.

[GTsRasta]

Originally Posted by Randy Chase

Beyond that, I do respect your intent on this thread. As I said, we did have some gains with one header, but at a loss of midrange and I am now running a different header that seems to work well with the SC and my intake and ECU.

Thank you for understanding.

[Murix]

Why don't you buy yourself a Lotus and find out for us?

[cory1000]

again, I dont get it...you dont own a lotus, you dont stand to profit from the sales of any of these parts, why gets your panties in a bunch??

[shay2nak]

Originally Posted by cory1000

again, I dont get it...you dont own a lotus, you dont stand to profit from the sales of any of these parts, why gets your panties in a bunch??

cuz he owns a car with the same heart as the Lotus...2zz familia

[cory1000]

and?

Originally Posted by shay2nak

cuz he owns a car with the same heart as the Lotus...2zz familia

[scottyb]

[ChrisB]

:sigh:

[jlj3394]

I think his analysis is interesting, although I don't really know/care who is right. But the guy shouldn't be bashed for offering an opinion, when in reality he is trying to help us all by figuring out if more power can be bolted onto this engine.

I personally enjoy many of his posts.

Know will someone tell me whether I get more or less power when the air temp here is 5 degrees and probably 20 below wind chill?

[RacyTracy]

Wind chill has no effect.

[codymac]

Originally Posted by RacyTracy

Wind chill has no effect.

Interesting for someone with no dog in this fight.

scottyb - don't bogart the popcorn, man!

[GTsRasta]

I'm just trying to figure out what the absolute "truth" is. Now that I got my long post out of the way...

1) Is it now safe to say that properly designed headers and exhausts can make power on the stock Lotus ECU?
2) Is the intake the only variable you guys have to worry about?

I know it was said that none of the aftermarket intakes dyno'd above stock...but was it just from the low-midrange...or through the whole rpm band? Be honest...because it seems weird that gains from dynos like the Fujita intake will be totally "unlearned", and proven to LOSE the power throughout the WHOLE rpm range...making a $240 investment worthless...even if it's only in part of the rpm range.

This is something else I want to know, because it was said that it "seems" that a Lotus is faster when an intake is bolted on and making more noise. Was there a loss in the low-midrange, but only a slight gain in the top end? That's what the Exige Motorwerks dyno shows, along with the fact that the same trend follows for the top end oriented Celica Injen CAI. Could it be that the Lotus intake designs are top end oriented, and not low-midrange oriented like the AEM CAI back on my car? Here's a nice thread with analysis and dynos back from 2002 by one of the best 2zz tuners in the world (who tuned Smaay's 550 whp, 1.93 Liter stroked 2zz beast):

http://www.newcelica.org/forums/show...ght=Injen+Dyno

Originally Posted by Jesse IL

I've had these for a while but haven't posted them. I bought an Injen 3rd gen CAI to compare with my AEM CAI. My car also has a TRD exhaust. I dynoed the car stock a while back as well. The same dyno was used both times as well as the same tire inflation pressure. This is how I tested the car to make sure the Injen and AEM results would compare fairly. I installed the Injen on a Friday night along with the TRD exhaust. I reset the ECU and cleaned the MAF sensor. The Injen was run about 200 miles total before it was tested, a mix of street, highway, and two days at the track. The best run was the morning after installing the intake/exhaust 14.8@98.95mph. I noticed with the Injen a massive lack of low end power compared with the AEM. The car also was hard to drive smoothly away from lights comparitively and had a big bog at about 4600 rpm under part throttle. You can see in the first dyno run that the Injen/TRD combo is killing the stock setup up top but is losing tons of power down low. The Injen HP line is red and torque line is green, stock HP line is dark blue and torque line is light blue.



On Wednesday night after dtnoing the Injen setup, I removed it and reinstalled the AEM, resetting the ECU again. The car was driven about 50 miles before it was run on Thursday at the dyno. The low end power and drivability off idle picked right back up and the part throttle bog disappeared. The first graph shows the AEM/TRD combo vs. stock (AEM HP=dark blue, torque=light blue stock HP=red, torque=green) As you can see, the low end power loss is significantly less than with the Injen.



Now this last graph shows the AEM/TRD vs. Injen/TRD This is where I was surprised. The Injen olny beat out the AEM by one peak HP. And the Injen only passed the AEM after 7300 rpm. Not only that, but the AEM absolutely killed the Injen down low. (In this graph AEM HP=dark blue, torque=light blue Injen HP=red, torque=green)



After having both intakes in my car, I can say that the AEM is a far better choice for street use. The fitment of the intake is far better, and there are no holes or stumbles in the powerband. That isn't to say that the Injen may not have some promise or does not have good aspects. It may be possible to tune the Injen with a S-AFC to make more top end power, because that seems to be where its powerband is biased. Also, the Injen puts the filter in a far better location than the AEM. The Injen has a sharp bend at the end which causes the filter to sit nearly vertical and up and out of the airstream coming into the front bumper. This is beneficial in two ways. First, the filter isn't constantly being bombarded with road debris. Second, I think that in real world use, the AEM may suffer a power loss at high speeds. Its filter is located right in the air stream entering the bumper. When you move air at speed past the end of a pipe, you have a pressure drop at the end of the pipe. At high speeds, there is alot of airflow through the front end, especially with ny TRD bumper that has a large gap between the plastics and the bumper. I am thinking of making a fiberglass ram air box to mount the AEM in that is fed by the opening in the front bumper.

So I hope this all was enlightening to everyone. More stuff can be found at my site http://www.ameritech.net/users/trdcelica/celica.htm

Could the "stumbles in the powerband" from our top end oriented Injen CAI be the 15 hp loss reported here in your top end oriented intake designs? These patterns are apparent in the Exige Motorwerks dynos...

Originally Posted by Randy Chase

Now, I could be wrong. You could spend a lot of time on newcelica pushing Lotus specific solutions?

I did, actually. There was some cool stuff that came out of this site that I shared over there.

[GTsRasta]

Here's another guy here with an intake testimonial, and who also argues that the intake must make somewhere in the powerband:

ReVerie vs Fujita

Now are the Lotus intake power losses in the whole RPM band, or just in the low-midrange?

[scottyb]

Originally Posted by codymac

Interesting for someone with no dog in this fight.

scottyb - don't bogart the popcorn, man!

Codymac stop hogging all the popcorn and give it back!

[RacyTracy]

Originally Posted by codymac

Interesting for someone with no dog in this fight.

Well, it doesn't.....is my saying that a problem???