4722 replies to this topic

[Darcini]

Surely the benefits of the right standalone would outweigh the cost though Nev? In the greater scheme of things would it not be a (very relative of course) drop in the ocean?

[Nev]

Surely the benefits of the right standalone would outweigh the cost though Nev? In the greater scheme of things would it not be a (very relative of course) drop in the ocean?

It's hard to know really. But at the very least Syvecs would cost around £2500 which would be around 20% of my entire project cost.

[slindborg]

tbh the OEM ecu is more than capable of doing what you ask of it, its just that as ever with 'remaps' they havent got full documentation/support/access to all the calibration etc and they simply cannot do the required job properly.

You have to work with the tools available, if you cannot get all the documentation/support/access to calibration that make the ecu not usable even if is the best ecu in the world.
From what I have been told and experienced the standard ecu cannot be live mapped making re-mapping very time consumming.

Steve

Agreed, its just that we all make the flippant comments about how "crap" the oem ecu is, when in reality its not crap it's the hacks the chooners do is crap



Nev, isn't the friend who "maps" in India getting eaten by mossies

[steveboyslim]

Surely the benefits of the right standalone would outweigh the cost though Nev? In the greater scheme of things would it not be a (very relative of course) drop in the ocean?

It's hard to know really. But at the very least Syvecs would cost around £2500 which would be around 20% of my entire project cost.

That percentage of project costs for replacement ecu and installation is about normal.
With the CLET engines I have built, most of the users want to use an engine loom, airflow meter and senors which are nearly twenty years old, then they install a 'go faster' chip which is often a bad copy of someone elses, which was infact programmed around a different specification engine and then they wonder why the engine melts or mis-fires.
Even to fit a more basic ecu, loom and parts, then get it mapped will cost the best part of £2k, more if drive by wire.

Steve

[Boombang]

Out of interest, when people use DBW on aftermarket ECUs, do they generally map the pedal directly against the throttle itself (whether linear or not), or do they map pedal to throttle with engine revs and load (i.e. 100% pedal may give lower throttle openings at lower revs and open wider at high revs - as would be on a factory DBW throttle system)? I suspect due to complexity in mapping, the pedal and throttle are directly linked, which IMHO makes retaining DBW pointless apart from packaging issues - and therefore unless the ECU you are purchasing that meets all other needs also just so happens to have DBW, you may well be better off buying an ECU that meets all other needs and then fitting the cable pedal option from the Elise.

[Nev]

Nev, isn't the friend who "maps" in India getting eaten by mossies :lol:/>

It's Chip whom I was referring to.

Another advantage of TC is that if I set it to 0% my rear tyres will last considerably longer, which would be quite a saving per annum.

Let me get the engine working again first and then I'll see whats left in the piggy bank. Also, before anything else, I need to refurb the steering rack + column UJs as it has quite a lot of play these days and has quite a bit of vibration from 80 leptons upwards (which is only 2nd gear!!).

Edited by Nev, 13 April 2013 - 08:30 AM.

[Thealastair34]

Can you not just fit a throttle cable t/b then go for dta or omex at say £650 then mapping at £350?

[Nev]

I'm not too keen on a cable throttle body TBH and would prefer to stay with my ETB, particularily as I have a 70mm Bosch one (ex Porsche 996) with a massive 76mm top hat that won't be a restriction. I know this eliminates 80% of the 3rd party ECUs though

Edited by Nev, 13 April 2013 - 08:54 AM.

[slindborg]

Out of interest, when people use DBW on aftermarket ECUs, do they generally map the pedal directly against the throttle itself (whether linear or not), or do they map pedal to throttle with engine revs and load (i.e. 100% pedal may give lower throttle openings at lower revs and open wider at high revs - as would be on a factory DBW throttle system)?

I suspect due to complexity in mapping, the pedal and throttle are directly linked, which IMHO makes retaining DBW pointless apart from packaging issues - and therefore unless the ECU you are purchasing that meets all other needs also just so happens to have DBW, you may well be better off buying an ECU that meets all other needs and then fitting the cable pedal option from the Elise.

That's what I've seen most of the time as even the bestest chooners don't actually understand what having an independantly adjustable throttle actually brings to the party.

[Thealastair34]

I'm not too keen on a cable throttle body TBH and would prefer to stay with my ETB, particularily as I have a 70mm Bosch one (ex Porsche 996) with a massive 76mm top hat that won't be a restriction. I know this eliminates 80% of the 3rd party ECUs though

for what reason?

a cable after market will be a vast improvement over stock with etb even if it is a porsche item

[Bumblebee]

I've heard mixed things with cable

[Nev]

I'm not too keen on a cable throttle body TBH and would prefer to stay with my ETB, particularily as I have a 70mm Bosch one (ex Porsche 996) with a massive 76mm top hat that won't be a restriction. I know this eliminates 80% of the 3rd party ECUs though :(/>

for what reason?

a cable after market will be a vast improvement over stock with etb even if it is a porsche item

In order of precedence, 5 reasons not to are:

1. The most important facet of keeping an ETB, is that the traction control can do a 'soft cut' by artificially part closing the TB plate. This results in a very smooth (and not even noticeable to the average driver) implementation of the TC. This is very important, as it avoids 'hard cut' where injectors are not pulsed, and stops stupid backfiring due to un-burnt fuel and that horrible stuttering that can unbalance the car just when you don't want it. The net result is that you can put your foot right down to the floor with 1000 BHP and safely go round corners right at the very limit of traction. This single feature would make a MASSIVE difference to you track day boys, and would also be epic on the road too. Basically you apply the power to the max almost all the time, some call this 'cheating', however in something like TA it would put you on the podium every time I think (assuming it's allowed).

2. Installing and building a cable operated pedal is expensive and hard. Dave Hardwick can do this and offers a great bit of kit, however, it is an extra "hidden" expense.

3. You'd have to source a manual TB and convert it to fit the mouth of the OEM inlet plenum. I do know a part that directly fits that you can buy for £40, but I have promised not to go public with this as the "knowledge rights" to this is someone elses.

4. Cables can dry out over time and might need replacement.

5. Cables can stretch over time and indirectly affect the mapping (possibly).

Out of interest, when people use DBW on aftermarket ECUs, do they generally map the pedal directly against the throttle itself (whether linear or not), or do they map pedal to throttle with engine revs and load (i.e. 100% pedal may give lower throttle openings at lower revs and open wider at high revs - as would be on a factory DBW throttle system)?

I suspect due to complexity in mapping, the pedal and throttle are directly linked, which IMHO makes retaining DBW pointless apart from packaging issues - and therefore unless the ECU you are purchasing that meets all other needs also just so happens to have DBW, you may well be better off buying an ECU that meets all other needs and then fitting the cable pedal option from the Elise.

Initially, I would probably map the pedal directly to the boost demand, though this is less fuel efficient (parcularily on mid speed straight motorway runs for example). However, if once you know the torque and power curve that your engine delivers, you could be more sophisticated and remap so that either the power line is a pure straight line, or such that the torque line is a pure straight line; (when I say straight, I really mean it - like a ruler). TDI in Essex did this for Chris Randal, to limit his power to a straight line of xxx BHP (to meet race regs) and it is very impressive.

Edited by Nev, 13 April 2013 - 10:25 AM.

[Nev]

Oooops, dup entry.

Edited by Nev, 13 April 2013 - 10:29 AM.

[siztenboots]

traction control as Nev says , plus flat shift and launch control

[slindborg]

Using air as traction control is usually the last resort as its damn slow compared to dropping power with less or more fuel and even better with less spark.

[Duncan VXR]

The next car going on the standalone package is retaining DBW setup and fully adjustable TC with switchable map both from in car. The DBW has been developing for some time but happy to now use it, car is harrop powered s/c DG

[cnrandall]

We map throttle position against torque output, ie 50% throttle = 50% engine torque. Really wouldn't want to go back to a cable throttle car, the DBw provides so much flexibility.

[slindborg]

We map throttle position against torque output, ie 50% throttle = 50% engine torque. Really wouldn't want to go back to a cable throttle car, the DBw provides so much flexibility.

Ohh properly, pedal = driver demand has been standard in oem for many many years, transit had that for my07 ( but I was working on it in 04 )

[Bargi]

The next car going on the standalone package is retaining DBW setup and fully adjustable TC with switchable map both from in car.

The DBW has been developing for some time but happy to now use it, car is harrop powered s/c

DG

Tell me more....

[Nev]

Premature posting !

Edited by Nev, 16 April 2013 - 05:41 PM.