Rb25/26 Serious Issues - Help/opinions

[Shockster0429]

The Microtech is fully programmable. Have you actually checked the base (idle) timing with a timing light? Does the Microtech have a timing trigger offset setting?

I have a RB25 running off a Wolf 3D, it's pretty stock (around 12psi) , but at full noise @6000, it runs around 8 degrees timing.

is this 8 degrees ontop of the static 15 degrees therefore 23 degrees? What turbo, power ect are you making?

You match the engine timing with a light to that of what the microtech is reading on the laptop by manually adjusting the CAS.

[SteveL]

From more research this afternoon this is looking like a CAS/trigger wheel issue.

Mate this is rubbish.....far more likely to be crap engine management/poor set up. The Nissan CAS is very reliable.

I've been running a (highly) modified FJ20 optical ECU with 6 cylinder components on an L28 for (far) more than a decade. I've never had a single problem with it. The difference is I run an engine management system from arguably one of the best manufacturer's in the world.....MOTEC. It has no problem at all with either the cylinder or timing indexes of the optical wheel at any rpm.

[Shockster0429]

Mate this is rubbish.....far more likely to be crap engine management/poor set up. The Nissan CAS is very reliable.

I've been running a (highly) modified FJ20 optical ECU with 6 cylinder components on an L28 for (far) more than a decade. I've never had a single problem with it. The difference is I run an engine management system from arguably one of the best manufacturer's in the world.....MOTEC. It has no problem at all with either the cylinder or timing indexes of the optical wheel at any rpm.

Maybe I should rephrase this.

"From more research this afternoon this is looking like a CAS/trigger wheel issue with my aftermarket EMS"

Does your trigger wheel have varying window openings? Or are they all the same? The believed issue is the windows changing their opening size. Did you go through and read any of the information links I posted?

[VB-]

it really does seem like its detonating... its alright for the tuner to say it wasnt, but its right there in plain view. you know on those 'funniest home video' shows you see the kid standing there covered in paint saying 'but it wasnt me!' while the hallway has now turned rainbow. thats your tuner

was he actually using anything at all to monitor knock?

[zebra]

it really does seem like its detonating... its alright for the tuner to say it wasnt, but its right there in plain view. you know on those 'funniest home video' shows you see the kid standing there covered in paint saying 'but it wasnt me!' while the hallway has now turned rainbow. thats your tuner

was he actually using anything at all to monitor knock?

+1

Just because you couldnt hear it knocking by just standing beside the car doesnt mean it isnt.

I cant hear my car knocking when im in it a full noise, And my car isnt that loud.

If your tuner is using Knock ears are they even set to the right frequency? a 4" Bore V8 with cast heads is gonna gonna sound nothing like an RB when its knocking.

[R31Nismoid]

Meh, you were told back last time, too much timing.

Again, everyone is saying too much timing.

I honestly dont care if the tuner tunes 3000hp V8's. Doesn't mean he's getting it right, and it seems exactly the case that he is not and its detonating.

#4 - was ear's on the motor/block to pick up the rattle/detonation over loud exhausts/dyno rooms and so on.

[MrStabby]

Ok...so lets bring it all together;

- There is consensus that its detonation from excessive timing

- The reason the engine died is that the detonation was not detected, and tuning continued through it -> THEREFORE to avoid another rebuild you MUST get functional knock detection going before you run the next engine

- Your tuner is using his knowledge from other motors which clearly does not apply in this case. So either you need to find an RB expert, or find some other way to address the risk of continuing to use this tuner. The knock detection will address some of that risk.

- The question of Nissan CAS with aftermarket ECU compatibility has been raised, so perhaps it would be worth trying Nistune with a standard ECU (difficult on R33 tho). You could then verify that there is no knock with factory maps (which would be a nice sanity check + starting point), and eliminate the potential compatibility issue.

- The readings you have for timing may be false, or the ideas you have about what is the right timing are false, or you may be calculating/measuring static compression incorrectly; in particular,

Fineline suggested that static compression of 9.0 is too much and that you should go back to 8.5.

blind_elk's RB25 with low boost runs 8 degrees of timing, you were running 16 (with the outstanding question of whether this is total or the increase over static).

When nothing makes sense, it means that something you think you KNOW is WRONG.

Good luck.

[SteveL]

Does your trigger wheel have varying window openings? Or are they all the same? The believed issue is the windows changing their opening size. Did you go through and read any of the information links I posted?

Mine does full sequential and, yes the windows vary in width. I had a brief glance at the links, but, frankly, as soon as I saw one of them was Hybridz I didn't bother with it much.

[peter_fc]

what were the intake air temps. the way the microtech timing has been set up seems a little odd. the ign timing should really ramp up to about (depending on the set up of course, and what the engine likes) 34-36 deg by about 3500 rpm and hold a straight line AND THEN your timing adjustment will be made from the other timing map adding about 5 deg in your cruize maps (25 & 20 in) and pulling out overall timing coming on and in boost maps.

You can also on the microtech retard timing if air temps or coolant temps get too high.

Pics show it was detonating very bad.

Let us know your air temps.

There is so much more in the microtech also. double check all settings in all areas. (can be confusing)

[discopotato03]

Detonation damage no question .

I have seen problems over the years with after market engine management systems trying to read Nissan optical crank angle sensors and I think a lot of stems from the fact that the aftermarket is using a minimul approach to adequate processing power .

From what I remember the Nissan CAS does two things , it provides 4 or 6 references pulses (the inner 4 or 6 slots) to tell the ECU which cylinder is rising towards TDC on its compression stroke (in prep for power stroke) . In later CAS's they made these 6 slots different lengths so the ECU could tell which cylinder was next without buggerising around doing a count from a No1 cylinder reference pulse .

I'm told the 180 (or is it 360) fine slots around the outside of the rotating disc it to indicate to the ECU rapid changes or transients in engine speed .

Now to read all this in real time the box (ECU unit) has to have adequate processing power to do it without any "ghetto" count back strategies .

Haltech , or Invent Engineering/EFI Technology , used to be close to me and in the early days I used an old E6A on an injected L Series four .

To run the injectors group fire and with a single coil was easy , I think the L had a reluctor dizzy/CAS , PITA system .

The next engine was an FJ20ET and I went to an Autronic SMC ECU , FJ's have an optical CAS/Dizzy and that created problems for the SMC possibly because with 16 bit CPU's aren't up to Motec standards (32 bit Motorolla CPU's ?) .

The fix for that setup was to alter the std Nissan CAS disc so that the photo sensors outputted signals the SMC could interpret .

This sounds dodgy/ghetto etc but it did work initially . The fella that made the loom removed the optical disc and , seriously , fitted a very thin metallic sticker over the outer most row of very fine slots . He then cut a small slot in the outside of the disc to correspond with the approach to no 1 cylinder .

So this becomes the no 1 sync pulse and the other four inner ones tell the ECU TDC for each cylinder .

I consider this a dumbing down of the CAS to suit basic budget engine management sytstems .

Nissan designed their OEM system to be very accurate and that what it takes to have a tight handle on what goes on .

There are (were ?) a number of places here in Australia that lazer cut new discs which fit straight into various Nissan CAS units alowing them to talk to "limited" ECU's .

With the money you've been through I'd either invest in one of those or use a system capable of reading and functioning off all the std (or whatever) engine sensors .

We may be infested with Power FC's here but they do work .

I in no way wish to insult you but to get good results I feel you really need a capable EMS because so much hangs off what those injectors and coil drivers do .

This is not in my opinion an area to economise in no matter what other people get away with . A couple of rattles and a bang is an easy way to spend lots more money than a capable black box bites you for .

I haven't used them but I like the sound of the Vipec V88 or whichever one it is that can run 6 injectors sequentially and 6 coils without a waste spark system .

Guilt Toy here runs the plug in version for a R33 GTS25T and doesnt have engine failures through knock . Gissmo gadget sounds great too .

Your call , cheers A .

Edited April 10, 2009 by discopotato03

[joeyjoejoejuniorshabadoo]

I search this site for Microtech issues and all I see is majority of people just bashing it giving no solid explanation to reasons they do not like it.

i think you'll find that its not so much bashed, as simply viewed as not worth purchasing over here because of the massive number of power fc's which are known inside out by every tuner and proven to work.... price difference is meh...

we have many cars on this site holding together better than yours using a microtech, so i'd say that's not the reason.... it could be part of the cause, if your tuner hasn't set it up correctly, nut not the reason.

as ash quoted, RPMGTR has said its detonation, and to look at your timing... i would look very closely at this, as ben is probably australia's premiere RB builder, and is trusted by many many SAU cars. his sentiments have been echoed by most everyone else here.

i do not know your tuner, and i can not comment on him personally, but do you think there is any chance that he was not careful?

i.e. could he have had the "i build >1000 hp american v8's, this little underpowered jap shit will be easy" attitude?

also query him on his knock monitering procedure... dont be afraid to ask.... its YOUR money getting shredded (or more appropriately, detonated) here

[T04GTR]

ok, wind the clock back... what happend when you first put the plenum on?

[T04GTR]

also, i know its hard to do now,, but check the exhaust cam cas pickup for ware.. and the cas itsself.. they can ware out and the rpm will be unstable.. mine for example the revs got over 7k and the timing would jump all over the place. the ecu was seeing 9k 11k 6k etc etc

i put a crank trigger on and problem solved..

[unique1]

also, i know its hard to do now,, but check the exhaust cam cas pickup for ware.. and the cas itsself.. they can ware out and the rpm will be unstable.. mine for example the revs got over 7k and the timing would jump all over the place. the ecu was seeing 9k 11k 6k etc etc

i put a crank trigger on and problem solved..

Hey Dave you are running an Autronic from memory? smc or sm2? Any pics of the crank trigger and where did u get the crank wheel and magnetic pickup from? i assume u run it off the balancer or did u go the flywheel option?

[blind_elk]

is this 8 degrees ontop of the static 15 degrees therefore 23 degrees?

No, 8BTDC. The Wolf gets a trigger at 60BTDC, then fires the spark at 8BTDC.

What turbo, power ect are you making?

I'm running a slightly upgraded turbo, but only running about 12psi. Initially, I got 180 awkW on a mid-octane fuel. After the recent rebuild, it dropped to 150awkW (I suspect I've got leaking valve stem seals, and the oil coming through them is dropping the "effective" octane)

[ReganGTS25T]

dood those injectors are CRAPPPPPP buy sards id never trust those inejctors in my life ive had a friend who had the same inejctors he flowed thema nd everything broke 4 2jz's 2 of them forged was the f**kign inejctors the whole time, i actualy bought "deathworks" too but thank god 1 of them came f**ked up and noticed how truly f**ked they are and bought sards hurt me to hell tos epnd clsoe to 1000 dollars in injectors between the crapy 1's and the sards but oh well if you buy cheap you get cheap

[Drift Motorsport]

Can you post up your fuel and timing maps in excel for us to see?

[Shockster0429]

dood those injectors are CRAPPPPPP buy sards id never trust those inejctors in my life ive had a friend who had the same inejctors he flowed thema nd everything broke 4 2jz's 2 of them forged was the f**kign inejctors the whole time, i actualy bought "deathworks" too but thank god 1 of them came f**ked up and noticed how truly f**ked they are and bought sards hurt me to hell tos epnd clsoe to 1000 dollars in injectors between the crapy 1's and the sards but oh well if you buy cheap you get cheap

No their not, they power quite a few high HP cars, they have been proven time and time again. Sorry for your buddies luck.

Can you post up your fuel and timing maps in excel for us to see?

Here is the timing map, mines on the bottom, above it is a PFC map we were comparing it too.

[DCIEVE]

Suprised you let the tuner 'tune' without some form of knock detection, doesnt cost much to make up a det-can. Given the custom plenum I'd also suggest monitoring individual cylinder temps - even stock plenums need large corrections, I imagine a custom job would be much worse. The innovate stuff should be nice and cheap for you over there.

Perhaps look into something like this next time: http://www.gizzmoelectronics.com/Product_KMON.html

That'd be handy but from all accounts they're a little difficult to set-up.

[Guilt-Toy]

i would never trust a microtech with my engine. i have heard some shocking story's on how far the timing can drift from the set values in the ECU. apparently the power fc does this as well!

Get a new ECU. power fc or a vi-pec and move on.

Looking at your map, there is NO way the timing values in the ecu caused the issue, the ECU is programmed correctly but it is sending incorrect / warped / drunk / drugged up high signals to the engine which is causing the detonation.

I know this is a long shot, the last battles i had with a microtech i was totally sure that the engine's cam timing / ignition timing was soo f**ked out and stuffed i kicked the car off the dyno and told them to go home and fix it. It ended up being that the harmonic balancer had NO keyway in it and was spinning on the crank! so when we set the timing it was out 25deg !!!

anyway good luck with it