Safari auto bow upgrade

[buddrick]

Hi, is there any up grades for the auto boxes or any tricks that I can do to my safari? When hits top gear boost goes down to 4pis but drop down a gear or out of overdrive and boost back to 9psi???

How do I put a photo under this?

[Crash bandicoot]

Load the picture up to a site say like facebook trademe or flickr then use the IMg button above your text you will see this come up

"[img ][/img ]"

then once your photo is loaded to the website right click on it and select

"copy image location"

click your cursor in between the two ][ of the following "[img ][/img ]" and then right click... Select "Paste" it should look something like this


"[img ]www.trademe.co.nz/photoserve/5746385.jpg[/img ]"

click on preview and you should have your picture embeded in your post.

as for your auto trans a big aftermarket oil cooler and a service.

as for your boost dropping on gear change sounds like your turbo is in need of some TLC as it should climb when the engine goes under load(in a diesel,not so much with petrol engines) as a diesel turbo is producing boost even at idle. In saying that a factory nissan diesel turbo engine(regardless of type) should be set at 12 PSI when the waste gate opens or the bypass valve is over come. where is your boost gauge hooked up to, is it tee'd into the waste gate actuator line or closer to the intake manifold.

To get a true 12 psi out of the turbo charger extend the waste gate actuator line and plumb it into the intake manifold, this will then negate any pressure drop between the turbo and the intake manifold.

[kbjj]

What revs is your engine doing in top gear when its only boosting 4psi? My td27t starts to boost at 1800rpm and is full boosting (15psi) at 2200rpm. I'm not aware of any turbo diesels that boost at idle, but if there is, I'm keen to learn more

[crazyclark31]

the factory turbos are pretty slow to boost up. I would say that the turbo is needing some attention if its dropping off like that though. As already said underload it should be boosting more than that.What revs is it doing when it happens?

Oh yea factory trubo safaris only boost at 7 1/2psi afaik

[coxsy]

so you found out boost is controled by rev's a smaller turbine may start to boost quicker,

[Crash bandicoot]

What revs is your engine doing in top gear when its only boosting 4psi? My td27t starts to boost at 1800rpm and is full boosting (15psi) at 2200rpm. I'm not aware of any turbo diesels that boost at idle, but if there is, I'm keen to learn more

the characteristics of diesel turbochargers create positive pressure from idle, as the RPM's of the engine are dictated by the fuel not the air like a petrol engine, this is why diesel engines do not have a throttle butterfly. and before anyone asks if your diesel has a butterfly in it's intake it is for the Exhaust gas return to reduce emissions as obviously exhaust gas pressure is alot higher then intake pressures, it is there to stop hot gases forcing there way back to the intake.

[kbjj]

What revs is your engine doing in top gear when its only boosting 4psi? My td27t starts to boost at 1800rpm and is full boosting (15psi) at 2200rpm. I'm not aware of any turbo diesels that boost at idle, but if there is, I'm keen to learn more

the characteristics of diesel turbochargers create positive pressure from idle, as the RPM's of the engine are dictated by the fuel not the air like a petrol engine, this is why diesel engines do not have a throttle butterfly. and before anyone asks if your diesel has a butterfly in it's intake it is for the Exhaust gas return to reduce emissions as obviously exhaust gas pressure is alot higher then intake pressures, it is there to stop hot gases forcing there way back to the intake.

I don't mean to thread jack, but It's sort of on subject...
I here ya, but . My egr system is completely removed, and I understand fuel (diesel) equals revs. But surely you need more fuel than just idle, to get more exhaust, to boost turbo ?? Or is my system not functioning correctly going by the boost/rev figures I've given?

[crazyclark31]

turbo is spinning therefor boosting just not at a big enough amount to read.
Think what crash is saying is in a petrol when its not boosting the intake manifold is running at a vacuum or neg pressure. On a turbo diesel the intake manifold is always at a positive pressure.This means that even at idle the turbo is creating enough boost to run the intake manifold at atmospheric or neutral pressure. thats kinda why diesels boost earlier and stay on boost when driving

Does that make sense? did in my head

[kbjj]

turbo is spinning therefor boosting just not at a big enough amount to read.
Think what crash is saying is in a petrol when its not boosting the intake manifold is running at a vacuum or neg pressure. On a turbo diesel the intake manifold is always at a positive pressure.This means that even at idle the turbo is creating enough boost to run the intake manifold at atmospheric or neutral pressure. thats kinda why diesels boost earlier and stay on boost when driving

Does that make sense? did in my head

atmospheric or neutral pressure is not possitive pressure thou aye.

afaik, heat (of exhast gases) is the key factor in driving a DIESEL turbo (i don't care about petrol). At idle there is not enough heat to drive turbo fast enough to boost/compress intake air on a 'normal' set up. This is the reason why people supercharge their diesels, to get boost at idle. Again, afaik, IF a turbo can be set up to compress intake air/or boost at idle, (ie, smaller exhaust housing/turbine), it would be too restrictive in flow, or run out of puff for the top end rev range. Please, correct me if I'm wrong
Jeremy

[crazyclark31]

your right there.
If a turbo is boosting at idle then aside from the fancy stuff it will, as you say ,run out at the high end.
Would be keen to see a supercharged diesel in action.

[Smurf]

your right there.
If a turbo is boosting at idle then aside from the fancy stuff it will, as you say ,run out at the high end.
Would be keen to see a supercharged diesel in action.

Any of the vids of Richards white doublecab hilux on this page.
http://www.offroadexpress.co.nz/Forums/ ... start=1230

[buddrick]

Boosts hard but with auto gbox hard to see just where in rpm is, I'm running 12psi at moment, went up down road over 10 times to check but seems that it comes on at 1700 rpm in second or 2100 third and is fine on the flat road very farst still after 120km had it doing 145km yesterday and thought if more road and I knew that no cop would hav pushed more! But what I'm finding is that when going up steap hill it will sit at 90km and 3400rpm but stil wants to go hard but then overdrive kits in (4th gear) and then revs drop to 2100rpm and boost drops and then got #### all I still can't work out how to up load pics as I have some nice ones of what I have done. I must say though that I really love the pwr water to air heat changer as as can thrash all day hard on beach and egt temps only get to 590'c but I have mine reading b4 the turbo not after as I don't understand y people have them after?

I think my exhaust turbine is to big or it's the low riving auto g-box that's the problem??????

[crazyclark31]

Is it a factory turbo?

[buddrick]

No it's all after maket comstom I would put up pics but can't work it out I'm not very good at this.

[coxsy]

Image shack works well photo bucket have dropped the spanner as a photo bombers site now