Fastcat Boost Control (ESM Chips - Performance & discussion)

[racerstev]

What is really needed once you start raising boost levels is a wideband O2 sensor.
You need to be able to see what the air/fuel ratio is to keep things safe.

In my experiance one bar (14 psi) is safe with our injectors and turbo. If you want to push
things a bit you can go as high as 20 psi lower in the rpm range as well. You will need to
bypass the stock fuel cut to get these pressure numbers though.

One more time, a wideband O2 is needed to try to run this high.

Steve

[rip]

What is really needed once you start raising boost levels is a wideband O2 sensor.
You need to be able to see what the air/fuel ratio is to keep things safe.

A standard closed-loop Elan goes open-loop under boost, so you would need to have the ECU completely re-programmed, or even replaced with a programmable one such as a Haltech. An Everest chip on its own would be insufficient.

Although your suggestion is a perfectly valid solution, from Phil's comments it sounds like this is way beyond the scope of his query.
I'm sure Phil will correct me but I don't think the Fastcat is closed loop anyway, therefore it has no O2 sensor at all.

[surfboardfiller]

Ian's right the car is an early model, however I fitted the wiring for an O2 sensor the other night, but purely for MOT and fuel economy when I'm on the road. +5mpg is worth the £20 the sensor cost.
As the ECU ignores the O2 sensor when on full throttle it probably won't help in performance with the standard ECU.

Having removed the boost control from the ECU I was concerned I had cut it off other things the ECU does that I still need it to do. If this was the case the safety would be removed and I could damage the engine.

From what Tony said, with the safety fuel cut off operating at a relatively low boost pressure it seems I need an Everest chip to solve that and the chip and ECU will still be able to operate successfully in all other tasks than boost control.

If I want to go over 1 Bar boost, I will need injectors that can inject enough fuel into the higher air pressure than normal, to fuel correctly.

It seems I need an Everest chip with the O2 upgrade and possibly a fuel cut point at a higher boost pressure. I'd really like confirmation that this is what I need from the man who knows and that I have not missed anything vital.
It would be nice if said Guru could offer some advice on the system regarding ECU/EEPROM Chip program.

[rip]

From what Tony said, with the safety fuel cut off operating at a relatively low boost pressure it seems I need an Everest chip to solve that and the chip and ECU will still be able to operate successfully in all other tasks than boost control.

If I want to go over 1 Bar boost, I will need injectors that can inject enough fuel into the higher air pressure than normal, to fuel correctly.

If you have bigger injectors, then I don't believe you'll need a different chip.

The correct bigger injectors deliver 50% more fuel. The ECU is will be unaware of this.
To balance this, a 3BAR MAP sensor gives the same reading at 3BAR as a stock (2BAR) one does at 2BAR... so there will be 50% more pressure (& therfore 50% more oxygen) than the ECU believes, so it will still be fuelling correctly.
The overboost cut should then become irrelevant because it is way above what you will ever achieve.

I am not sure if there are any other issues with running this setup, but I believe several Elans are set up like this.
Tigerdog's Elan is.
So is Dico's...but he never drives it

[surfboardfiller]

Will that work at the top of a mountain? or will it only work at 1 bar atmospheric pressure?
Obviously Dico's car won't work anywhere as it has no driver

[racerstev]

The wideband on mine dosn't connect to the ECU, just a diaplay on the dash.

The way I did it was this. 1st diable the boost cut with a zener diode, install wideband and display,
fill with the high octane fuel, pull 2 degree's of timing, install boost controller.

Start raising boost and keep an eye on the air/fuel ratio's, it will be really rich in the area of
10.0 to 1 under boost. Keep turning the boost up untill the A/F is around 11.5 to 12 to 1. This is
a very safe tune. You could keep going but no farther then 12.5 or so in IMO.

Steve

[rip]

Will that work at the top of a mountain? or will it only work at 1 bar atmospheric pressure?

The ECU samples atmospheric pressure when you turn on the ignition & works out all its pressure measurements for boost etc. against it.
It will be fine on a mountain assuming this is where you are when you start your engine. If you drive up (or down) a mountain, you will need to turn your engine off & on again to reset its atmospheric reading.

Geoff told me that & at first I thought he was kidding....but he wasn't.

[saska]

Phil, I'm not trying to rain on anyone's parade and please don't take what I say as gospel -- I'm just offering an opinion on what you're doing though I'll try to give my reasoning.
The Mountain chips offer more protection than just the overboost and fuel enrichment at high revs/boost.
1. Boost is limited to 0.5bar when the coolant temperature is below 50°C or when any fault code is set
2. The boost is progressively reduced if knock retardation exceeds 5°
The first isn't that important because you aren't dumb enough to hammer a car before it is fully warmed but the fault code & knock retard are.
None of the above will work with a SBC
I'm not convinced that a solenoid BC will offer better wastegate control than the stock system. I don't know the type you have so I could be wrong but the stock boost control valve is a pulse modulation type which operates many times a second. This type of valve uses a constant frequency square wave signal but varies the pulse width so they are fast and accurate.
So what I'm trying to say is that even if the boost controller you have does offer better wastegate control there won't be much in it.
More to the point; is what you lose worth the slight difference ?
Now for a bit of a ramble lets look at some scenarios and I'm assuming you don't want to go into boost over 1 bar, Haltechs, 3 bar MAPs etc. what are the options and their pros/cons.
Stock chip with SBC
-will boost to whatever you set the SBC at or 0.92Bar when the ECU cuts the fuel
- don't know what the fuelling map looks like between 0.65 - 0.92 bar but it is likely ~10.2:1 (rich)
- you lose the engine protections in 1 & 2 above
Everest V4 with SBC
- will boost to whatever you set the SBC at or 0.98Bar when the ECU cuts the fuel
- again don't know fuelling for sure but since ESM says the V4 doesn't adjust fuelling so I'm assuming ~10.2:1 (rich)
- you lose the engine protections in 1 & 2 above
Everest V4 with stock BCV
- will boost to 0.9bar and cut fuel at 0.98bar
- again think this is likely to be the stock fuelling, so on the safe side at ~10.2:1 (rich)
- you get all the engine protections
Elysium V5 with stock BCV
- boost to 0.95bar mid range dropping to 0.9bar at high revs, cuts fuel at 1bar
- fuelling map giving less safety margin (leaner) so 12.3:1 vs 10.2:1
- you get all the engine protections
Elysiun V5 with SBC
--boost to whatever you set the SBC at or 1bar whichever comes first but no boost change between mid-range & high revs
--fuelling map giving less safety margin so 12.3:1 vs 10.2:1
--you lose the engine protections in 1 & 2 above

Looking at the options above and given that this is for a track car how do things stack up.
Going from a stock chip to an Everest means the fuel cut is raised from 0.92bar to 0.98bar but the fuelling at high revs/boost is per stock (safely rich at 10.2:1)
So with the SBC & Everest you can get another 0.05bar (0.97bar) but if this causes knock and retard the ECU can't do anything about it because it can't control the SBC
With Elysium & SBC you can get 0.07bar more than a stock chip and more power from the less safe fuelling (~12.3:1) but again if this causes knock/retard the ECU can't do anything about it.
You'll have noted the Elysium V5 does 0.95 bar mid rev range but lowers boost to 0.90Bar at high revs and on ESM's web site he says they tested with dyno, gas analyzer and Elanscan to detect knock. So the idea was to squeeze all you could out of the engine without causing knock and retaining all the engine safety features.
My concern is the car is for track use and therefore is likely to be run at high boost and high revs exactly when knock is most likely to occur so I don't think running say 0.95bar at 6000+ RPMs is a good plan with some of the safety features disabled. Others will tell you there is more to be had from the engine and I don't necessarily disagree but where do you draw the line called 'safely for the engine' ?
Were I in your shoes an Elysium V5 with stock BCV would be my choice -- you get more power from 12.3:1 A/F ratio, 0.95bar mid range and 0.9bar at high revs and all the engine safety features. Further, I'd ask ESM if he could put the V5 map straight on a chip so no switcher board was required. Simpler, less things to go wrong and you're unlikely to want any of the low performance settings anyway.
Only remaining question I'd think is to O2 sensor or not. Since the ECU goes out of closed loop at higher throttle -- I don't think there'd be much in it. Instinct says closed loop is better but that's about it for a track car.
Sorry for the length of post but hope it helps your deliberations.

[surfboardfiller]

Yes the Elysium looks good if it can go on a single chip, I will have to start with an Everest to get the car running and moving and check everything is running well first.

I'd like to go to a higher boost pressure eventually (maybe 1.3 bar) but I'm not sure about injectors and the map sensor, it's another grey area to really learn about, but not yet.
I want O2 for road and MOT, I have put some wires in place but need to splice the wires at the ECU end as the car is a 1990 G Reg.

The important thing is that the engine will run fine and the safety of the Lotus ECU Map is intact; so I can get the car going as this is really stage 1, whilst other may see it as a track ready stage it's really not.

I also need an Android app of Elanscan if I record the Elanscan data but I may be dreaming.

[surfboardfiller]

Can I plug any ECU into my car? I have a few and one had an Everest v4.5 chip in it.

[saska]

Can I plug any ECU into my car? I have a few and one had an Everest v4.5 chip in it.

It's the chip (mem-cal) that is important and should match whether the car has an O2 sensor.
So 9929/9939/9930 chip without an O2 -- 9930 has revised CO pot to meet emissions.
1499 with an O2.

[surfboardfiller]

Thanks Tony. I have 9929 in the car (no surprise). I have Adams old ECU with an Everest and O2 1499 to get the car up and running.

[ESM]

Sorry I'm late to the party. I'll chip in with my tuppence worth. Apologies for the many replications from above - there is a lot of well informed stuff with more detail than I'm going to go to!

The standard Elan engine management controls boost via boost solenoid valve (BSV). The system is pretty simple one

1) Whether a boost target is required is determined by various sensor inputs (CTS, RPM & TPS primarily)
2) A target boost is set based on throttle position (TPS) and engine speed (RPM) but the boost target may be modified downwards if knock is detected.
3) An active control loop is used to reach and hold the target boost.

This process works entirely independently of fueling, timing etc. The ECU determines what timing and fueling to employ based on the sensor inputs that pertain at any given time. So putting on an MBC does not mess up fueling and timing. What does mess up the fueling and timing is taking the boost beyond the range of the MAP sensor. It can read up to 1 bar of boost. Consequently the engine maps in the ECU only go up to 1bar. The stock injectors can only flow fuel fast enough to fuel for 1bar of boost (and not even that at top rpm). So getting 1.2 bar out of a stock system, in my view, qualifies as a bad idea. This is especially true because when an alternative boost control method (MBC or whatever) is employed the ECU can no longer pull back on the boost target when knock occurs. That said the 4XE1-MT engine seems to tolerate an amazing about of abuse of this type. People have fitted the dreaded FCD (which kids the ECU boost is lower than it actually is to prevent fuel cut) and basically run the turbo without restriction. You are welcome to take your chances with this but it's not an option I have any interest in exploring myself!

In short; control boost however you want but unless you want to risk going lean or get into MAP sensor and injector changes don't go past 1bar of boost and don't distort readings to the MAP (or any other) sensor. The mountain chips top out where they do for a reason.

[tigerdog]

Tigerdog's Elan is.

Yup it is. As pointed out above, it's the balancing act of bigger injectors giving more fuel, offset by 3 BAR sensor telling the computer to send less fuel that more-or-less balances out. The 3BAR map also tricks the computer so fuel cut doesn't occur until around 1.3 BAR or your engine blows, whichever comes first. This means your boost control, whether electronic SBC or crude MBC, removes much of the protection built into the stock ECU and mountain chips. So why do I still have an MBC? Because there isn't an ESM alternative for the 550cc+3 Bar combination yet (t-dog crosses paws/fingers, wishes upon a star.) If you plan to go above 1 Bar, this is the necessary first step.

[surfboardfiller]

I think the way to go for me is to set the boost at 1 bar with an Everest 1499 chip fitted for now (until the car is running nicely) and cross my paws that ESM makes a map that is compatible with the increased injector size and 3 bar map sensor.

The good thing about the boost controller is that I can change the setting easily with some common sense and new knowledge applied and if I get to improve the flow and knock detection. 200 BHP isn't enough for my track car although an Everest would be fine for the road car.

[Monty]

Started a thread a while ago on fitting my 550 injectors and 3bar map viewtopic.php?f=44&t=19162 but would need to buy the EBC and wideband sensor and gauge. I didn`t get round to doing it as my spare dosh is going on my old Tranny

[Dico]

my spare dosh is going on my old Tranny

I just fell off the couch Quote of the decade from the Murphmeister

And another great quote-

So why do I still have an MBC? Because there isn't an ESM alternative for the 550cc+3 Bar combination yet (t-dog crosses paws/fingers, wishes upon a star.)

And another-

cross my paws that ESM makes a map that is compatible with the increased injector size and 3 bar map sensor.

[ESM]

Unfortunately I can't really see a 3bar MAP/bigger turbo version coming along unless I get a bigger turbo and 3bar MAP sensor myself as

1) I'll have something to use for development/perform tests on

and

2) I'll have an incentive!

However, I'm selling my good car (the steel blue one). The one I'm keeping (red car) has some engine damage and, at the moment, a broken TCA. It needs a lot of stuff doing before I add more performance (even supposing I could get my hands on a suitable turbo).

I have a wide band sensor kicking around waiting for me to get the red car sorted. It's a nice piece of kit because it can simulate a narrow band sensor output so it can be used for closed loop control with the standard ECU as well as having the ability to monitor high boost mixture.

[surfboardfiller]

I think what we need is a chip that calculates the fuelling for the bigger injectors and the capability of higher boost pressure, without the fuel cut killing us (or no fuel cut and a sensible safety feature instead).

The small IHI Turbo is fine as it's well matched with the engines small CC (it should work with a bigger turbo as the fuelling is based on air pressure anyway).

I guess all you need is a 3Bar map sensor and some bigger injectors for Christmas/Eid/Divali/Hanukkah

I don't know how much they cost though. - Doug?

[Monty]

I have a wide band sensor kicking around waiting for me to get the red car sorted. It's a nice piece of kit because it can simulate a narrow band sensor output so it can be used for closed loop control with the standard ECU as well as having the ability to monitor high boost mixture.

Be interesting to know which wideband that is as i`d would like to fit one in the future

I guess all you need is a 3Bar map sensor and some bigger injectors for Christmas/Eid/Divali/Hanukkah

I don't know how much they cost though. - Doug?

IIRC, when Dico and I got ours from ther USA the injectors worked out at £280 and the MAP was roughly £30