[Mk2] [Turbo] What can you do with the stock ECU?

[rs007]

For the last two year I have been racing with 1.5 bar boost on a stock Rev 2 engine, it has never been taken apart. This year changed to a CT20b at the same boost and never had a problem.
The head bolts have had an extra 90 deg turn on each of them and run on 110 octane fuel

My son has a t3/4 turbo, 263 cams, side exit exhaust, charge cooler and all running on a Rev3 ECU

Just out of interest, how would you describe the difference going from CT26 to CT20b?

Does it spool quicker? Just wondering if it would be a worthwhile swap for fast road driving, if one were to come up affordably

[bobhatton]

For the last two year I have been racing with 1.5 bar boost on a stock Rev 2 engine, it has never been taken apart. This year changed to a CT20b at the same boost and never had a problem.
The head bolts have had an extra 90 deg turn on each of them and run on 110 octane fuel

My son has a t3/4 turbo, 263 cams, side exit exhaust, charge cooler and all running on a Rev3 ECU

Just out of interest, how would you describe the difference going from CT26 to CT20b?

Does it spool quicker? Just wondering if it would be a worthwhile swap for fast road driving, if one were to come up affordably

Not quicker but it holds boost at higher revs where the ct26 drops off

[rs007]

For the last two year I have been racing with 1.5 bar boost on a stock Rev 2 engine, it has never been taken apart. This year changed to a CT20b at the same boost and never had a problem.
The head bolts have had an extra 90 deg turn on each of them and run on 110 octane fuel

My son has a t3/4 turbo, 263 cams, side exit exhaust, charge cooler and all running on a Rev3 ECU

Just out of interest, how would you describe the difference going from CT26 to CT20b?

Does it spool quicker? Just wondering if it would be a worthwhile swap for fast road driving, if one were to come up affordably

Not quicker but it holds boost at higher revs where the ct26 drops off

Thanks - probably not a worthwhile upgrade for me then, I am not interested in revving the balls off my engines, so it dropping off boost from 5ish upwards isn't an issue for me. I'd like it spooling quicker tho!

[jimGTS]

Thanks - probably not a worthwhile upgrade for me then, I am not interested in revving the balls off my engines, so it dropping off boost from 5ish upwards isn't an issue for me. I'd like it spooling quicker tho!

seriously?

this gets OLD real quick! lol

making power up to 6500-7k makes for a nicer drive, (bigger rev range for the twisties).

you wont find anything that spools quicker than a stock ct26, lol. thats is instant boost.

[bobhatton]

On my new engine I do not want boost in till 4000 - 5000, to try and stop the wheels spinning

[Turbonoz]

There is still enough fuel for 19psi on a ct20b on the stock ecu, 440s and pump.

Without a doubt. I don't know where people get the idea that 440cc injectors run out of 'puff' so early. Back in the day I ran 383bhp@hubs on a set of 510cc Evo injectors in a stock 1809cc CA18DET.

IMO my car always ran like a dog on stock management...one of the reasons people think the engine/pistons/gasket is weak is because of the stock ECU getting its knickers in a twist and hitting det.

Cher-ching! Knock is the limiting factor on the stock set-up. Then you need to worry about two parts of the fuel system to ensure stable fuel supply: The fuel rail and the fuel pump. Relatively involved jobs that the average guy isn't going to bother with IMO.

For the last two year I have been racing with 1.5 bar boost on a stock Rev 2 engine, it has never been taken apart. This year changed to a CT20b at the same boost and never had a problem.
The head bolts have had an extra 90 deg turn on each of them and run on 110 octane fuel

Did exactly the same re. head bolts. Out of interest, what management are you running?

[Turbonoz]

you have 20 years service history including everything in japan?


sorry, but i dont see how a stock turbo can run those levels to redline.

how can a boot mount, ebc and ecu possibly "help" it run high boost to redline. that is really no different to any other bolt on setup.
i would like to know how you think this setup helps over others to run high boost to redline?

perhaps the exhaust housing was worked on and you didnt know?

im not saying your setup didnt run that boost, but i am saying i find it hard to believe it was a bone stock ct26.

stock ecu only have fuel maps up until fuel cut, some say rev1/2 was at 13psi, some say rev1 is 13psi, rev2 15-16psi.
i dont know where i read it, but someone plugged into the stock ecu and saw duties at 100% when it was over fuel cut levels. still had timing maps obviously.
how true this is, am only going on what i read.

The Rev 1/2 ECU has calibrated fuel maps for 14 & 16 psi, but these are locked. I am reading a chapter on it now, as opposed to just skimming through it as I normally do. The ECU does in fact use the fuel & spark values from 12psi for all higher boost levels (ref. J Hartman & Tadashi Nagata). As I said before, I've not worked with an ECU that does things differently yet.

As far as my set up goes regarding the CT26, it was a stock CT26 operating in a system suitable for 500+bhp. I had the Profec B & an additional boost gauge confirming what I'm saying now, 1.35 bar. If you say it was a hybrid of some sort, that's fine. But it wasn't

I didn't say that an ECU can help top end boost

[jimGTS]

you said you had a boot mount, ebc and link ECU.
then went on to say until someone replicates that then you wont know if the ct26 can be boosting 1.3bar at redline.

that to me sounds like your saying these are the mods you need, which is why im asking how those mods make it possible?

that turbo IMO was different to a bone stock turbo.
people over the past 20years have been complaining about the way the ct26 drops off in boost before redline.
it doesnt magically make more boost at redline with a few choice mods.

doesnt make any sense to me.

but ill believe and you can believe in what you choose.

just a healthy debate is all

[rs007]

seriously?

this gets OLD real quick! lol

making power up to 6500-7k makes for a nicer drive, (bigger rev range for the twisties).

you wont find anything that spools quicker than a stock ct26, lol. thats is instant boost.

Hahaha you are possibly right, I guess I am just a pansy

I think my car isn't boosting as quick as it should and IME I've been in plenty (admittedly other marques) that boost quicker.

I am in the process of ironing everything out and putting small things right - maybe once it is all running as sweet as I feel it should, I'll be happier

[Turbonoz]

you said you had a boot mount, ebc and link ECU.
then went on to say until someone replicates that then you wont know if the ct26 can be boosting 1.3bar at redline.

that to me sounds like your saying these are the mods you need, which is why im asking how those mods make it possible?

that turbo IMO was different to a bone stock turbo.
people over the past 20years have been complaining about the way the ct26 drops off in boost before redline.
it doesnt magically make more boost at redline with a few choice mods.

doesnt make any sense to me.

but ill believe and you can believe in what you choose.

just a healthy debate is all

It ran solid boost levels on the stock ECU. The exact same set-up needs to be replicated, and then that person can either agree with or refute my findings. All I can go on are the values that were recorded, not what the interweb tells me. I don't listen to other people in this respect. Not out of ignorance or pig-headedness, I would just rather find things out for myself, empirically. I'm well aware you can't cheat physics, but how many people have run a CT26 at high boost levels with a 500+bhp set-up? 3" intake tract, huge BMIC and safe in the knowledge if it blows, it doesn't matter. This is what needs to be done on a stock CT26 rather than me repeating myself ad infinitum, whilst someone else states I'm wrong.

A boot mount with 3" tract means minimal restriction, but more of a pressure drop. An EBC controls boost, so of course it's needed for top end boost control. I think wires have been crossed somewhere.

[bobhatton]

Did exactly the same re. head bolts. Out of interest, what management are you running?

Its all stock

[toyokid]

I ran 17psi on my Rev 2 Carlos Sainz Celica for 4 or 5 years
the CT26 fitted as standard had steel internals,
when I had the engine forged I fitted a ceramic CT20b and found with the lighter wheel the spool was quicker, good mid range but seemed to run out of puff at the top end.

You could buy my Apexi power fc AP engineering ecu which would I believe connect straight up to your car and run,
if you were to add an inlet air temp sensor and map sensor you could get rid of the afm.

Stephen

[rs007]

I ran 17psi on my Rev 2 Carlos Sainz Celica for 4 or 5 years
the CT26 fitted as standard had steel internals,
when I had the engine forged I fitted a ceramic CT20b and found with the lighter wheel the spool was quicker, good mid range but seemed to run out of puff at the top end.

You could buy my Apexi power fc AP engineering ecu which would I believe connect straight up to your car and run,
if you were to add an inlet air temp sensor and map sensor you could get rid of the afm.

Stephen

Getting rid of the AFM would be desireable... for reference, is the Apexi unit you mention mappable?

[JMR_AW11]

you have 20 years service history including everything in japan?


sorry, but i dont see how a stock turbo can run those levels to redline.

how can a boot mount, ebc and ecu possibly "help" it run high boost to redline. that is really no different to any other bolt on setup.
i would like to know how you think this setup helps over others to run high boost to redline?

perhaps the exhaust housing was worked on and you didnt know?

im not saying your setup didnt run that boost, but i am saying i find it hard to believe it was a bone stock ct26.

stock ecu only have fuel maps up until fuel cut, some say rev1/2 was at 13psi, some say rev1 is 13psi, rev2 15-16psi.
i dont know where i read it, but someone plugged into the stock ecu and saw duties at 100% when it was over fuel cut levels. still had timing maps obviously.
how true this is, am only going on what i read.

The Rev 1/2 ECU has calibrated fuel maps for 14 & 16 psi, but these are locked. I am reading a chapter on it now, as opposed to just skimming through it as I normally do. The ECU does in fact use the fuel & spark values from 12psi for all higher boost levels (ref. J Hartman & Tadashi Nagata). As I said before, I've not worked with an ECU that does things differently yet.

As far as my set up goes regarding the CT26, it was a stock CT26 operating in a system suitable for 500+bhp. I had the Profec B & an additional boost gauge confirming what I'm saying now, 1.35 bar. If you say it was a hybrid of some sort, that's fine. But it wasn't

I didn't say that an ECU can help top end boost

You have to be careful what you choose to believe when looking at what is written about the rev 2 ECU operation.

I reverse engineered this ECU several years ago and the main fuel and ignition maps are arranged as 'safe' maps and 'normal' maps.

Depending on how the ECU detects and stores knock history in its RAM the ECU swaps between these two maps. So neither is locked out.

From memory one set of maps has fewer table entries and maybe this is why people think one set is some kind of 'locked' out high performance variant.

However, the ECU is designed to be datalogged in real time with a computer and you can see the ECU swap between the two map sets soon after an ECU reset if you datalog the flag that decides which map set it is currently using.

eg it will start on the safe (fuel and ignition) maps and jump across to the larger normal maps quite quickly if the ECU detects no knock.

I haven't looked at these ECUs in years but I do remember how the ECU manages knock and how it decides when it gets enough persistent knock across the rpm range (after any initial ign retardation and fuel enrichment strategy fails to prevent the knock) that it decides to swap back to the safe maps to be doubly safe.

BTW you can remap the Techtom ECUs quite easily as the program code is stored on a removable/reprogrammable EPROM. There is a very noddy amount of 'scrambling' protection in the form of swapped/flipped address lines (IIRC) but it is trivial to work out the pattern they use for each vendor.

[rs007]

Well well well!!!!

Finally got a boost gauge fitted - and even fully warmed up, could now see I was only getting 7ish psi / 0.5 bar.

My T-VSV must be non functional!

Set it to the factory 10ish psi /0.7ish bar using a MBC and what a bloomin' difference!!! Thing takes off and pulls like a train. AND the turbo really bloody whistles now!!!

Happy bunny! I knew something wasn't right, could just feel it.

I did put it up to 14ish psi / 1 bar - but I am not entirely confident in either the engine, or the gauge to be fair. With the gauge I am more worried that the sensor that feeds it can only read up to 1 bar - I have no evidence of this, but I was winding that screw in more and more, but it never wanted to go over 14ish psi... unless boost build isn't linear, meaning the higher you go, the more turns it takes to get just a small increase...

But basically, I was worried I was running mega high boost, but the gauge was only reading 1bar... mind you there was no evidence I could feel of fuel cut or anything like that...

Anyway as I say, its running at a healthy factory level of boost now, and I am pretty impressed now!

Still, always room for more!

[bazpro]

iam in the same position as you mate, bought a rev2 few weeks back which seemed slow and wasnt running much boost
at first i thought maybe the boost was turned down as clutch might be on its way out so fitted a boost controller and set it to 0.8 bar and am pretty happy with it now, seems quick enough .
but have noticed how crap my brakes are now !!!!!!

[rs007]

iam in the same position as you mate, bought a rev2 few weeks back which seemed slow and wasnt running much boost
at first i thought maybe the boost was turned down as clutch might be on its way out so fitted a boost controller and set it to 0.8 bar and am pretty happy with it now, seems quick enough .
but have noticed how crap my brakes are now !!!!!!

Tell me about it!

Apparently the EBC red stuff pads are s**t hot, those, some new discs and new fluid are how I'm going!