Very Dissapointing dyno result 1uz + gt42r

[millsi]

took the hilux down to pits today for a tune.

ended up with only 220rwkw@10 psi

it did have a slight miss still in the top end but only affected power by 5hp or so (didnt miss on every run)

so on that front looks like i will need to upgrade to a cdi and some decent coils.

regardless of that, it still should have made 100hp more than it did on the same boost.

eg that green silvia with the same engine, same trans and similar sized turbo went 32x or 33xrwkw on 12 psi. and not just that car but plenty of forced 1uzs making similar figures.

fuck, when it was on the che dyno, it started breaking down at 7psi 4000 rpm and made 230rwkw???

anyway heres the sheet, note the 261hp (195kw) was as tested before the tune.



the only thing i can think may be wrong is the cat is melted and/or blocked???

thoughts?

i have also posted this over at pf

fuckn pissed off and genuinely upset. so much time and coin has gone into this. very fuckn over it

[oldcorollas]

AFR's good?

using similar size/design of exhaust manifolds to the silvia? similar size and core design of cat/s?

[Aust162]

maybe write up a quick list of the engine/driveline specs for those not familiar with your build.

something is definitely not right obviously. did your tuner suggest anything you should look at?

it will be something simple no doubt.
Air flow, fuel, compression, electrics.

is the timing belt on correctly?

[JZA70 R]

first of all, we cant see fuel or ignition timing so we dont know how its been tuned...
youre running 10psi on a massive turbo that probably doesnt wake up until 25
and you have obvious ignition issues that need sorting.

how bout you rectify those issues and stop comparing dyno numbers with other cars before getting upset over how your setup is performing. and whos to say that its not performing as it should for that boost/tune, regarless of what your mates are making.

[millsi]

this is the build thread
http://www.toymods.org.au/forums/sho...t=15177&page=9

cat is fine, pulled cooler out, no blockages.

[millsi]

first of all, we cant see fuel or ignition timing so we dont know how its been tuned...
youre running 10psi on a massive turbo that probably doesnt wake up until 25
and you have obvious ignition issues that need sorting.

how bout you rectify those issues and stop comparing dyno numbers with other cars before getting upset over how your setup is performing. and whos to say that its not performing as it should for that boost/tune, regarless of what your mates are making.

afr's are spot on around 12:1.

did you even read what i posted?
the runs where it didnt break down (and was a very small miss) only resulted in a 5hp drop.

[beerhead]

How much voltage drop to the coil? Volts setting on the multi meter - 1 lead on the battery + terminal other one on the coil power. Getting close to 14V with the motor running at the battery? If you're getting ignition break down there has to be a reason. Seen problems with too cold a plug being used on a 4AGTE making endless troubles too.

[millsi]

i dont have a multimeter but could prob get a mate to check.

plugs are bkr7e, and gapped to 0.6mm, 7 is one heat range colder than stock

[thechuckster]

just a thought - what was the auto doing? was it locked up during the power run-up?

and is the wastegate firmly shut until you hit your boost limit?

otherwise, you could be at the bottom of the efficiency map of that turbine - did you do any runs at a higher boost level?

[millsi]

chuck, didnt run it any higher due to the slight ignition breakdown.

auto was unlocked, i showed him the lock button as i thought that how most poeople would tune??? but het hes widely regarded as one of the best tuners so i didnt want to throw stupiud question at him, stall is 3000 so after that the converter should be near direct drive.

gate is remaining shut perfectly, hold a nice steady boost as shown by the graph

[abently]

Boost leak? Pressure test the system up to 30 or 40psi.

[JP]

have you checked the ignition advance for timing drift through the range?

[NME308]

Hi there mate,
Weak ignition is not only going to cause problems just at the point of audible break down. I've had weak ignition make it look like I had lean fuel mixtures and upping the fuel resulted in no power gains. There was no actual breaking down - just lack lustre power.

Weak igniton can be hosted by other factors not just the traditional bad coils or plugs:
Poor earth systems. The heads need to be earthed by straps to the block which in turn needs to be earthed to the battery. I prefer to have one up front say off a waterpump bolt and a 2nd engine earth from one of the starter motor bolts. Chassis and body also need to be connected to battery earth.
A poorly performing ignitor due to faulty part, wrongly selected part, poor wiring, or possibly wrongly configured ecu output.
Spark plugs once properly fouled by a tuning issue can often be useless thereafter. Boosting on the transbrake with an overly lean or rich mixture can trash spark plugs for me. You can clean them, or keep running them and they may work somewhat, but new ones are inevitably required.

Off the weak ignition band wagon, I run a pair of GT35r turbo's and they are not at all interested in playing until around 14psi. At the 14psi mark you can just hear the familiar whistle which quickly builds to jet engine sound a split later! I'm not familiar with the compressor map on the GT42r and where a 1UZ plots on it, so its just a general thought. Different turbo's will flow varying amounts of air so one turbo may be perfectly happy supplying 330kw's of power at 10psi and another may still be in surge at the same point...

Cheers,
Jason

[millsi]

abently, yeah thats what i thought how ever the indicated pressure on the eboost is read off the manifold and its prety steady.

jp, no unless the tuner did it today. i must say i wouldnt know how to check it myself

nme, the chassis and bodt are earther but the heads to the block arent. plugs came out looking fine.
as for the turbo, yes your right about sizing, however it sounds just fine when it comes on as you explain. 10psi of air on a turbo that size should produce decent amount of air

[JP]

to check the timing drift, you lock the ignition timing in the ECU and rev the engine through the range while watching the physical timing with a light. With everything setup correctly the timing shouldn't deviate from the setting it's locked to in the ECU.

Doubtful that would be the main cause of your issue but it could be a contributing factor.