R34gtt Intercooler Into Stagea

[benl1981]

Thanks SK. Running standard boost on the dyno (about 7psi) the AFR were going as low as 10:1 - does this mean it was starting R&R?

I had 1.1mm gap plugs before, replaced with 0.8mm NGK - no difference. I checked timing yesterday and looks to be about 18deg BTDC. Wondering whether I should gap down to 0.6mm?

Just envious of other R33 owners who can get up to 12psi without trouble. I wonder why mine is different..

[Sydneykid]

  benl1981 said:

Thanks SK.   Running standard boost on the dyno (about 7psi) the AFR were going as low as 10:1  - does this mean it was starting R&R?    

I had 1.1mm gap plugs before, replaced with 0.8mm NGK - no difference.  I checked timing yesterday and looks to be about 18deg BTDC.  Wondering whether I should gap down to 0.6mm?

Just envious of other R33 owners who can get up to 12psi without trouble. I wonder why mine is different..

I am surpised just like you, there must be an answer, or maybe several answers, a few little things that add up to a problem.

I have never had to go down to 0.6 mm, the lowest I ever tried was 0.7 mm and it was no difference to 0.8 mm.

I would try advancing the ignition up to 20 degrees, maybe even 25 degrees and see what happens. Listen for pre-ignition very closely, around 3,500 to 4,000 rpm when you load it up, in say 3rd or 4th, going up a long hill is best. If you can hear the pinging then retard it and try again, same hill, same rpm, same gear. Keep retarding until it doesn't ping. Then check it with the timing light and see where it ends up. That rules out ignition timing as an issue.

An A/F ratio of 10 is low, but I have seen 9's before they start running rough.

I assume the air filter and fuel filter are clean and the AFM has been cleaned recently. Yes?

Injector clean and flow test would be on the list, after I had checked that the fuel pressure was OK (36-38 psi at zero boost or vacuum).

Do you know anyone with a Consult screen you can borrow? That will tell you if you have a crook sensor, water temp, TPS, knock etc.

Have you had a leak down test done, ever?

[benl1981]

Thanks SK for the ideas.

I think I am at the limit of advance as I have heard slight pinging before so I retarded the timing 1-2 deg and haven't heard it since

1. Fuel filter looks new. Last owner had it done (about 1 year ago) and have the reciept. Maybe I should get a new air filter.

2. I'll clean the AFM - with contact cleaner? Or anything else just as good. - I have carby cleaner at home...

3. Well on the dyno at stock boost it was at 10:1. The car runs perfectly at stock boost - but increase it a little and it kind of hesitates a little as you rev it out. The more boost you run the worse it gets.

4. Havent had a leak down test but it uses no oil and oil is only a little dirty at 5k kms.

5. Don't know whether I should still be looking at coils as there is a little light around them still, maybe this is normal. Although going from 1.1mm to 0.8mm made no difference - if coils were the problem this should have helped??

One night had the boost controller set to about 10psi. I went up a steep hill in 4th - as boost came up to 9psi (at around 3000rpm) the engine almost died. Quite viscous as if I just put on the brakes or lost all forward momentum. If it were coils this probably wouldn't be the case??

The engine doesn't blow smoke or use coolant etc. It feels more as if it is ECU or some thing sensor related that causes it..

I might take the car to UAS as they know skylines.

I can hear a little hissing around the PCV valve hose cannot really see a leak or anything though. I'm wondering whether I could have an intake leak somewhere but not sure how to tell. As this would mean that more air has to travel through the AFM to maintain the same boost level...however when they dyno ran it they didnt find a leak. You would think under boost you would hear one..

Bit annoying...

[benl1981]

Hey Sk - could you read the above, hope it's not too long.

Also, you mention about asvancing base timing. Could it be possible that I should be retarding rather than advancing. I'm just thinking that maybe the ecu isR&R due to it knock sensing. What do you think? I can't hear any pinging at the moment..

[Robo's]

Ben

Sounds like your fuel is way too rich when you boost it up, it gets richer, sounds like you need a power fc or at least SAFC

[Sydneykid]

  benl1981 said:

Thanks SK for the ideas.  

I think I am at the limit of advance as I have heard slight pinging before so I retarded the timing 1-2 deg and haven't heard it since

1. Fuel filter looks new.  Last owner had it done (about 1 year ago) and have the reciept.  Maybe I should get a new air filter.

2. I'll clean the AFM - with contact cleaner?  Or anything else just as good. - I have carby cleaner at home...

3. Well on the dyno at stock boost it was at 10:1.  The car runs perfectly at stock boost - but increase it a little and it kind of hesitates a little as you rev it out.  The more boost you run the worse it gets.  

4. Havent had a leak down test but it uses no oil and oil is only a little dirty at 5k kms.  

5. Don't know whether I should still be looking at coils as there is a little light around them still, maybe this is normal.  Although going from 1.1mm to  0.8mm made no difference - if coils were the problem this should have helped??

6. One night had the boost controller set to about 10psi.  I went up a steep hill in 4th - as boost came up to 9psi (at around 3000rpm) the engine almost died.  Quite viscous as if I just put on the brakes or lost all forward momentum.  If it were coils this probably wouldn't be the case??

7. The engine doesn't blow smoke or use coolant etc.  It feels more as if it is ECU or some thing sensor related that causes it..  

8. I might take the car to UAS as they know skylines.

9. I can hear a little hissing around the PCV valve hose cannot really see a leak or anything though.    

10. I'm wondering whether I could have an intake leak somewhere but not sure how to tell.  As this would mean that more air has to travel through the AFM to maintain the same boost level...however when they dyno ran it they didnt find a leak.  You would think under boost you would hear one..

Bit annoying...

Suggestions follow;

1. Fuel filters are cheap, change it. What air filter are you using? If standard, they are cheap too, buy a new one. Or a Pipercros for $50 for better flow.

2. We use brake cleaner, carby cleaner leaves residue.

3. That's standard ECU R&R, nothing unusual there.

4. Sounds OK, but if you have leaking valves (for example) the oil tests are irrleleant and won't show up anything. Leak down test takes about 1 hour, well worth it.

5. Coils, coils, coils everything gets blaimed on coils. I have never replaced a coil on a RB, maybe I am just lucky. Or maybe its becuase I dry the coils out after I wash the engine, some people don't and drive it with a river of water in the plug valley. Stuffs coils real fast.

Gapping down helps lazy coils and does nothing for stuffed ones. But what you are describing is not a miss (as in 1, 2 or 3 failed coils). All 6 would have to have failed, I don't think so Tim.

6. Nope that's ECU R&R, when it happens on the dyno the car lurches around madly, particularly the 4wd's (GTR's and Stagea).

7. Refer 4 above.

8. Worth a try, please post up what they find

9. Is that with the engine running? Or Off? Leaking around there is a sign of blocked PCV valve, take it out and give it a good clean in some kero. Check the rubber seal while it is out, they wear due to heat. Silicone sealer can help.

10. I would check the AFM voltage, connect a multimeter while driving and look at the voltage. That will tell you where it is on the 0 to 5.1 volt scale.

As a few others have already said, it sounds like it's time for an SAFC, DFA or Power FC. The Stagea was real bad on ECU R&R at 8 psi and 10 to 1 AFR, now it runs perfectly using the DFA.

Hope that helps some more

[benl1981]

Thanks again SK!! You're really helpful.

Should I connect the multimeter into the ECU or just run some wire through to the AFM. I don't really want to have to cut the wires unless I have to. Do you know at what approx voltage the cars ususally go R&R - is it about 4.8v (I guess it depends on a few factors)?

I can hear a leak around the PCV when car is running. not very loud though but you've given me a few thing to try before I go to UAS. But I think it might be powerfc time.

My coils look ok..the fact that is doing a huge big cut in the power delivery means that I must be bordering on the ecu R&R (unless something else), but it isnt really a miss like you say. I think if I had a leaky valve I would notice it on 7psi right? It's very smooth at stock boost.

Ive got it set on about 9psi now and it ran ok this morning (reset ecu last night), but it feels a bit dead at certain rpm and the at the power isnt as smooth as it could be - maybe just a bit of R&R as you say.

Powerfc time I think - that is after I check all the things you've mentioned

Thankyou!!

PS. I can definately see a little light around the coils - even with my friends set that work at 14psi. Maybe you could see light on all cars if really dark and have the middle cover off. On the side slightly, not a shooting arc just some faint light. There is no burn marks oon either set of coils!! Or cracks..

[Sydneykid]

  benl1981 said:

Thanks  again SK!!  You're really helpful.  

Should I connect the multimeter into the ECU or just run some wire through to the AFM.  I don't really want to have to cut the wires unless I have to.  Do you know at what approx voltage the cars ususally go R&R - is it about 4.8v (I guess it depends on a few factors)?

Either way will work, I do it at the ECU because it is closer and I don't have to run wires though under the bonnet. All you need to know is the pin outs to locate the AFM signal. You are measuring voltage so you don't have to cut any wires, just stick the multimeter probe into the rear (exposed) of the ECU plug.

There is no absolute AFM voltage, it's more a change in voltage. Run it at the highest boost you can get without R&R and note the voltages. Then increase the boost to the amount where you have a problem and note those voltages when it is R&R'ing. That should tell you what the limit is at various rpm's.

What I have seen on the R32GST Commander (when I jack up the boost) is a big jump in AFM voltage at an RPM range (usually around max VE, 4,500 tpo 5,000 rpm). It goes 3.0, 3.0, 3.1, 3.2, 3.2, 3.9 ....that's the problem (not the 3.9 itself) but the 0.8V jump. The Standard ECUs' don't seem to like this and they go R&R (the PFC doesn't care of course).

On the Stagea I used the DFA to smooth out these sort of jumps by correcting the A/F ratios. That accomplished 2 things, stopped the A/F ratios creeping too rich and removed that jump in the AFM voltages. I also used the IEBC to smooth out the boost curve, as the standard turbo gets onto boost very rapidly when the wastegate is held closed by the IEBC solenoid.

Since I retarded the exhaust camshaft timing by 4 degrees, I have noticed a little bit of the R&R has crept back. It feels flat occasionally (not all the time) at 3,000 to 3,500 rpm, so I probably need to do a bit more smoothing. Obviously the change in exhaust camshaft timing has increased the airflow to just over the standard ECU comfort zone. I guess that's a good thing because I know I haven't wasted my time fitting the adjustable exhaust camshaft pulley.

[Sydneykid]

Bump just in case it isn't noticed as it is older than 30 days now.

cheers

[AMS]

Cheers Gary

[StageZilla]

sk i think u should write a book on modifying skyline engines, u would sell a bloody heap and make cash

your a great help to everyone on the forum

[AMS]

  StageZilla said:

sk i think u should write a book on modifying skyline engines, u would sell a bloody heap and make cash 

your a great help to everyone on the forum

<{POST_SNAPBACK}>

That sounds like a fantastic idea StageZilla - it would be very helpful for all Plus Gary....*cough*....My Dad is a publisher

[Sydneykid]

  AMS said:

That sounds like a fantastic idea StageZilla - it would be very helpful for all Plus Gary....*cough*....My Dad is a publisher 

<{POST_SNAPBACK}>

If I only had time (that's a song isn't it?) :lol:

Maybe I should just put all my posts together in one document and sell that.

Sort of like a collection of short stories.

Shakespear did it with sonnets, so Sydneykid can do it with posts

Now all I need is a catchy title B)

Cheers

[Tangles]

Off topic, sort-of.... Im selling my R34 GTT Intercooler. See for sale thread if anyone is interested....

bwilkeson

[Sydneykid]

I am getting a few PM's about this upgrqade, so I thought I might bring it back to the front.

Cheers

[wolverine]

i'm selling the SMIC too.

(so back to the top you go)

[dineth]

hey bit of dumb question to you SK, is a DFA a piggy back?

[FLYSLY]

yes it is, also if anyone is interested i have a R34 GTT intercooler if anyone is interested

[AlexCim]

should have sold it 4 weeks ago...i'd have bought it.

[FLYSLY]

whoops, why arent you putting a FMIC back in the stag alex