Boost spiking on 3 litre CRD

[FatBoyzInc]

Hi all,

Late last year I had a 2.75" Beaudesert exhaust fitted as well as a DP Chip. Took a while to reallise the benefit of the chip as it wasn't the ball tearing performance upgrade that the supplier made it out to be. Anyway, although the exhaust was obviously doing its part of the job, I was not happy with the sound. It was just too quiet. I spoke to beaudesert and decided to order up the straight through pipe section that replaces the muffler. I am now happy with the sound (at least around town, it may be too drony on the highway). The problem is when accelerating the boost is spiking. Flies up to about 15PSI and then bounces up and down between 10 and 15. The sound coming from the snorkel is wierd and reminds me of the sort of noises I make if I take a short run (gasping for breath type sounds) I have heard you can get boost control tees that fix the issue but am not sure what I should get or where to fit it. Is it supposed to go in a boost or vacuum line? Any advice would be appreciated.

[threedogs]

Could be a faulty gauge but I think you need to NADS your Patrol EGT and boost gauge on a pillar pod.
Manual boost controller or Dawes valve plus a needle valve will keep yor boost undr control, You could block your EGR as well, What number is your Chip on too high and it will just blow black smoke I've found 8 is a good number for towing . Giving me plenty of power to overtake

Snorkel sound is normal

[FatBoyzInc]

Thanks Threedogs,

Gauges are just cheap SAAS but they are working, you can actually feel the "fault" when it is occurring. The car surges in time to the spikes. My chip does not have the rotary dial, instead it has a small jumper which you move to change the setting. Settings are 1 to 7. Comes preset on 4, installers had it set to 3 and told me that I needed to upgrade the intercooler to run a higher setting. I put a fan under the intercooler and now run it on 5. At this setting pre ditching the muffler I did a run to Longreach. There is a long steep climb as you cross the drummond range, not only did I climb it in 5th without losing speed, I overtook a truck and hit 130kph as I passed him without the need to go back to 4th.

[the evil twin]

An I/C fan does bugger all once you are over about 30 or 40 KPH and at much higher speeds acts as a blockage (the fan body).

If the installers said to run it on 3 or below without a larger intercooler have you tried it back at 3 to see if the surging disappears.

With a Chip and a bigger exhaust a long uphill pull in 5th gear like you describe will give astronomical EGT's
I would suggest not doing that on a regular basis without an EGT gauge.
If you already have an EGT and it was staying below 550 deg. then that is OK

[threedogs]

Strange my DP chip I change with a small screwdriver. Have a read of what Chaz yellowfoot says about the ZD30 motor.
Check all your vacuum lines are in position and not cracked, as ET says fans are only for low speed work like sand driving.
Is your IC is oily chances are its leaking. The Cr is more tolerant of high temps than the Di.
You can buy a sock to fit inside the snorkel but not sure that will make the wheezing go away

[FatBoyzInc]

Thanks for the replies,

Evil, no I haven't tried detuning it yet but will give it a go. EGT's hit about 600 on that climb but were only there for a very short time, I'll have to be a bit more careful in future.

Threedogs, the car is only 5 months old. Has about 7000klm on it, no oil anywhere at all (Think there might be a bit in the sump) The wheezing will go away when the boost spiking is under control, I can tell it is related as it is in sync with the spikes. Sounds like it is pulling huge quantities of air when the boost is at 15psi but then the boost drops to about 10psi and you hear less air being drawn in. Almost immediately the boost goes back to 15 and then back to 10 over and over. The sound I am hearing is what I would expect given what is happening inside the engine bay.

[threedogs]

I can only suggest you check all boost hoses and IC hoses , so your saying its not holding boost??

[FatBoyzInc]

When under heavy acceleration I am seeing boost climb rapidly, then the ECU seems to catch it and knocks the boost back. Boost climbs again almost immediately, ECU catches it again. Steady moderate acceleration is fine as the boost does not spike, so the ECU keeps it's nose out of it.

[boots]

If you are not happy with the rapid / irratic boost surge as it is then a dawes valve is the cure . As for snorkel intake noise at 15psi boost most of them do it . The remedy is to close your passenger window and enjoy . The Toyos in lux and cruiser variant are even worse cause the snorkels on the drivers side pillar.
Plenty of info on dawes valve setting up and where to buy . Let us know how you go .

[Drewboyaus]

You could always swap it for a 4.8 petty and enjoy the sweet song of induction roar all day long! LOL.
I crack the passenger window on my 4.2 just to enjoy it......

[nipagu7]

you may just need a needle valve to slow the rate that the boost increases . this might stop the problem . the later cr models seem not to overboost as much as the earlier models that require the dawes valve to control boost levels .

[the evil twin]

When under heavy acceleration I am seeing boost climb rapidly, then the ECU seems to catch it and knocks the boost back. Boost climbs again almost immediately, ECU catches it again. Steady moderate acceleration is fine as the boost does not spike, so the ECU keeps it's nose out of it.

As nipagu7 says... sounds like the spool rate is too high now you have those mods.
If (I stress IF) that is the case you need to adjust the VNT actuator or install a Dawes and Needle valve setup.
Dawes limits pressure and Needle Valve adjusts the spool up rate

[shimon22]

I think you need to change the entrance of the air flow to the turbo by increasing the pipe to 2.5 inch end the air gasket.

[Hodge]

G'day Fitz. I've had a mirror image of your problems, with my Patrol. Except I didn't have a chip. Everything you mentioned, my patrol was replicating it after I installed my 2&3/4 BD exhaust. The air sucking snorkle sound after I back off the throttle to the drone sound of the exhaust and the boost spikes.
I had the dawes and needle valve fitted 3-4 days ago mate and the difference it made to the car is unreal. Smooth boost and acceleration. EGT's dropped by a 100 all around. The snorkle sound is gone, and supposedly now my exhaust sounds different too. I cannot recommend the manual boost control enough. I'm spewing I procrastinated on installing it for months. Now I'm happy. It's like a different car.

[scottsauto]

i have to agree with hodge manual controler is the goods