Lakeside Lotus engine management upgrade

[Russc]

Here is a fun idea to try!!!....
If you want more boost sooner than the everest chip will give it to you, then get a couple of metres of hose the same size as the one attached to the wastegate actuator and use it to replace the original, the extra length delays the wastegate opening early but keeps the benefits of controlling unwanted high boosts.

I have not done this, It was suggested to me by a friend!! The Japanese also use a sort of storage "can" unit that again delays the onset of the actuator when they modify their cars.

Or change the wastegate for a forge item with a different spring. This is what the owner did on mine.

That with the MBC and slightly different tubing produced the same results as a BBR kit.

But, no it hasn`t damaged my engine, that i can see. But it did prevent showing that the wastegate was stuck open. This can`t be good.

It all depends on what you want, if you want the protection that was built into the cars then go for the chip, if you arn`t bothered then go for the BBR/bodge.

It`s all down to choice and preference. However if i wanted a car that accelerated madly i wouldn`t have bought the elan!

[Monty]

Funny how u can't explain how u'r own car was boosting
You seem to forget u'rs wasn't a BBR just an FCD and the BSV completely bypassed which means the turbo was giving all it's got, so abit more of a thump than a propper BBR kit

Almost Murph, almost.

'You seem to forget' I has a 'squish' in the stock exhaust which restricted boost.

Oh yeah ristricted it to about 1.4 bar

[Enright]

Here is a fun idea to try!!!....

Seems like Russian Roulette with engines to me.
Perhaps only every 6th one will go bang.
But do you want that one to be yours?

[Ashaman]

I want as much boost as possible as soon as possible without uncontrollable wheelspin - simple as that.

Want less power? Don't press the throttle so hard

An uprated wastegate actuator seems like a good idea, I think the stock one tends to creep open the whole time (totally unproven theory), as others said, losing boost in the lower RPM range were I definitely do not want it.

[mikeydude]

I want as much boost as possible as soon as possible without uncontrollable wheelspin - simple as that.

Want less power? Don't press the throttle so hard

An uprated wastegate actuator seems like a good idea, I think the stock one tends to creep open the whole time (totally unproven theory), as others said, losing boost in the lower RPM range were I definitely do not want it.

Try the pipe idea, cheap and easy, let us know how you get on.
It is supposed to be better than an mbc...it still allows the ecu to control the turbo (well eventually).

We could simply kidnap Alans dog (if he has one) and tell him he gets it back when he passes us an "under the counter" chip.

So...Russian roullete or not..once again...what I am talking about is not sustained overboosting with all the pre-ignition, weak running, and detontation risks, I am talkng about the car simply developing normal power but when the driver wants it, as opposed to the ECU telling me that I can't contol a bit of wheel spin!

Surely a ecu programmed with good overboost control is all that is needed.

Perhaps people could tell me then, other than extra drive train stress what the difference is between having the extra boost at higher speed and having boost from a standing start or fairly low speed?

Hey, other than less cooling air flowing though the intercooler!! just thought of that one.

I suppose mking an engne develop any more power by any means will assist in it deteriorating eventually no matter what...!!

[mikeydude]

Russc said.. "But, no it hasn't damaged my engine, that i can see. But it did prevent showing that the wastegate was stuck open. This can't be good"

That is the kind of problem that will damage the engine! ...no you are right it can't be good!

[ESM]

[We could simply kidnap Alans dog (if he has one) and tell him he gets it back when he passes us an "under the counter" chip.

Good way to get a chip that'll really lunch your engine

So...Russian roullete or not..once again...what I am talking about is not sustained overboosting with all the pre-ignition, weak running, and detontation risks, I am talkng about the car simply developing normal power but when the driver wants it, as opposed to the ECU telling me that I can't contol a bit of wheel spin!

Surely a ecu programmed with good overboost control is all that is needed.

There is little doubt the engine isn't tuned anywhere near it potential. However, the fuel cut IS NOT 'the ECU telling me that I can't control a bit of wheel spin!'.

The fuel cut occurs at the point the fuel system can no longer deliver enough fuel to hold the required a/f ratio. If you go North of 1 bar of boost with the stock fuel system you will run leaner than target and you will get pre-ignition. Engine speed and injector flow rate are the limiting factors. At 2000rpm the fuel injector has 60ms to inject the fuel required for the next combustion stroke at 6000rpm it has 20ms. The fuel injectors flow at 320cc/min so the fuel system has a fixed limit on how fuel it can deliver at a given engine speed. You can fuel for 1bar at 4500rpm but not at 6000rpm. You can't fuel for more than 1bar of boost at any rpm because the standard MAP sensor can't read beyond that level and so it can't know how much fuel to inject.

In FCD equipped cars the 'lean problem' is made worse by the fact that the MAP sensor reading is clipped at a level well below 0.9bar never mind 1bar (usually 0.7-0.8bar). So when the ECU is only trying to fuel for, say, 0.8bar and the boost is actually 1.4bar (it has happened) - that gives a mixture of 13.6:1 - ask anyone who knows anything at all about engines if that's a good mixture to run at 1.4 bar of boost.

The ECU will retard the ignition when the knock is detected and that is what I think has saved a lot of FCD equipped cars. That means you are one sensor failure away from a blown engine - sounds a lot like Russian roulette to me. Do it enough and it'll probably melt stuff anyway.

Perhaps people could tell me then, other than extra drive train stress what the difference is between having the extra boost at higher speed and having boost from a standing start or fairly low speed?

The chips use a feedback loop top control boost and that means there is some lag between setting and hitting a target. This is most apparent in low gears where the time between shifts is lowest. The passive wastegate is faster. Early chips didn't get much past 0.5bar in 1st but the latest chips (V4.4+) should be pretty rapid to hit the target - I optimised the control loop with that in mind. You could disconnect the BCFV and put in an MBC, set around 0.9 bar, with the chip to get faster boost but then your maximum boost would then vary with atmospheric pressure and since boost control would no longer be under the control of the ECU one level of safeties would be removed.

It is a fact that people who get the 1+bar boost at very lean fuelling levels (stuck wastegate & no fuel cut) report a lot of power but it will compromise engine life. Anything you do to exceed 1bar of boost that doesn't address the fuelling goes into my book as a bodge that has the potential to pop your engine. You need a 3bar MAP sensor, higher flow injectors and a new control system mapped to deliver the appropriate levels of fuel. Nitrous is worth considering (that'll need extra fuelling too though).

If the chipped car feels that slow I'd look at its state of tune - it shouldn't be all that sluggish.

[Monty]

Alan,

Always good to read u`r replys as they gives my pea brain some education lol

Just a thought

Since some are thinking of a turbo upgrade which will cost a couple of grand which is to much for me, what about an alternative.

If we stick with the stock turbo
bigger injectors
3bar map sensor

and if there`s a few who jump on board could you programme a chip to say boost to 1.1 bar with the right fuel ratio etc. I`m sure people would pay for u`r time to do this

[dapinky]

I love these topics - they're a hell of a steep learning curve for me!

I admit that before I came on to this site, I knew NOTHING about tuning Turbo cars properly - A bit of a fiddle with the wastgate on a cossie was all i did, but i never knew how or why it worked, and the damage it was causing (not my car, so it didn't matter - the taxpayer can foot the bill!)

I'm great with N/A tuning - after all, lumpy overlapping cam profiles, high compression and f***ing big carbs are quite simple principles to grasp.

Even NOS is quite simple - cooler (therefore more dense) charge = bigger bang!

All of these principles are controlled by simple mechanical means - but throw a load of sensors and electronics into the game and i have to take my hat off to people like Alan who do all this work for the likes of me to benefit

Rest assured, I will continue to support the mountain chip development (and stick with my switcher chip setup) until either:-
a) i get rid of the car (not likely, as it's not even mine )
b) i win the lottery and can afford to blow up an engine or 2 (also not likely as i don't play the lottery)

Basically it seems (for us mere mortals) there are 3 options:-

1) leave it standard and enjoy the car as it was designed by experts (accepting that things have moved on in the past 20 years)
2) support the development done by others (ESM, LGM, Costas, Phill etc)
3) go it alone and see what happens

After all, it would seem quite an easy way to get loads of extra power by disconecting a couple of sensors and the wastegate and putting your foot down

[mikeydude]

Many thanks Alan for taking the time to give us this great info.

I now appreciate more some of the issues here.

Perhaps though I should try to make a bit more sense here and clarify exactly what I meant.

I fully appreciate that Fuel cutout was put in place for a good reason. I understand that it is pretty bonkers to run the engine with boosts higher than say one bar..

..but this is the subtle bit that I was trying to put forward, It was
more of a question than anything....

When I first bought the car it was a stock setup that had a stuck closed wastegate. When I worked this out I was always careful to keep the boost below one bar and not get fuel cutout (I was quite good at it) , I assumed that this would mean that I was still running the engine in a manner that would not cause any immediate or long term damage to the engine etc.

Now, when I fixed the wastegate my lovely "kick in the back" as I think it was described by someone, disappeared.

When I then fitted the everest chip, I thought all that power would return but with all the safety features of overboost prevention in place and even the additional benefit of a higher fuel cutout setting.

But, it did not. Granted there was a huge increase in performance over stock, and high speed performance was great, But there seems to be a lack of acceleration that the car used to have.

Upon speaking to an associate of mine, who is highly regarded in the Esprit scene, his opinion is that some of this lack of acceleration is down to the very analogue mechanical nature of the wastegate actuator operation as opposed to it being more of an on off thing. i.e to be able to fully open the wastegate to control overall high boost, it has to start opening much earlier than is ideal which saps precious boost.

Now, my associate says that the effective negative feedback that controls boost should come entirely from the ecu not from a very linear un-tuneable mechanical air pressure system. This would allow much better control of the wastegate by keeping it closed fully at lower boosts and this reduces lag problems etc. giving the feel of much more initial power.

This would seem to tie in with what ESM was saying about this later version of the chip, being more responsive.. perhaps this is what I am missing, and it will be less stressful for your dog!!!!

Or am I talking gibberish again?! as usual!

[mikeydude]

Right,
Yes I think I have answered my own question......

Alan refers to it in his documentation as....

"boost pickup rate"

perhaps this is the controlling factor in the "stuck wategate with stock ecu (but keeping within fuel cutout) versus everest mod debate"!