Finally Turboed my 1HZ - Do these Figures Sound Right???

[Landcruiser Tom]

Hi All,

Finally put a turbo on my 1HZ 80 series - a factory CT26 with factory inlet and exhaust manifolds, and 3" mandrel bent exhaust.

At 80km/h in 4th I'm cruising at about 7psi, at 100km/h I'm cruising at about 10psi boost. Max boost I have seen is about 11psi. I've turned the fuel screw in a bit, and with a 16 foot van in tow up a fairly steep hill I have maxed out EGTs at about 630 degrees Celsius (probe in manifold before turbo).

I don't feel the turbo has made a massive difference to my torque. Maybe I'm expecting a bit too much, but I thought the car would climb hills noticeably better towing my van than it did before, and while there probably is a difference, it's not like "wow man, now we're movin"

I haven't driven a turbo cruiser before, and don't have any mates that have one (they all have petrol 4 wheelers) so I don't really have anything to measure my car against, but I just feel it probably should go a bit better than it does.

Any thoughts???

Tom.

[jsttry]

all the figures seem about right, my auto 1HDT sits at similar boost levels after tweaking. EGT seems reasonable for pre turbo, may have a little more in it, not sure on what pre turbo figure should be though.

Throw it on a dyno to see how it goes.

[Kitika]

Maybe not enough fuel but the egt's sound about right. You won't get petrol performance out of it as it is a slug. I'd dyno it and make sure the fuel system is top notch or it might fry like mine did

[FKT08]

I would definitely look at getting it professionally tuned preferably on a 4W dyno. This will make all the difference.

[Z()LTAN]

U can get some very good power/torque figures out of these engine with the right turbo.

But as kitika says, they dont last awful long like that.

[Landcruiser Tom]

I'm thinking of adding a boost compensator and getting it tuned - got a price of $885 to fit and tune - sound pretty reasonable?

They claim that by adding the boost compensator they can tune for more power across the rev range than not having one - does this sound right?

I know I'll definately have less initial black smoke off idle and potentially cleaner oil which is not a bad thing.

I use my car for a mix of 4 wheeling, touring and towing a caravan, so I can see the advantage of fitting a compensator if these claims are true.

Thanks,

Tom.

[howesy]

If its not bellowing out black smoke then put the screw in a little more. generally half to 3/4 turn from std is around the mark when you fit the turbo but go by the smoke. Even 1/16 of a turn can make a huge difference when your close to the mark.

[hdj105]

The CT26 is smaller than ideal for the 1HZ, causing greater heating of the intake charge and less air mass, therefore higher EGT's.

It will be better than no turbo, but not as ideal as the right turbo.

The fitment of a boost compensator (BC) means that they can tune it for higher peak power (exactly the same as they could achieve without the BC) however without the low rpm / off boost smoke.

[Landcruiser Tom]

Greg,

I hear what your saying about the CT26 being a little smaller than ideal for a 1HZ.

I rarely (never) see over 3,000rpm. I can see that a bigger turbo would suit higher revs, but had hoped the CT26 would suit my needs reasonably well. At one stage I was going to fit a turbo from a Nissan 300ZX (still have the turbo if anyone needs one) but a mate who was going to give me a hand making a dump pipe and inlet to suit never quite got the time, so when the CT26 became available I grabbed it.

My main intention was to chase more torque for towing the van up and down hills. I could live with the lack of power everywhere else, but hate holding people up on single lane roads while I power up at a massive 50-60km/h if I'm lucky (don't let me tell you about last summer when I had to climb over Mt Hotham with the van hooked up).

Thanks,

Tom.

[KiwiBacon]

The CT26 is smaller than ideal for the 1HZ, causing greater heating of the intake charge and less air mass, therefore higher EGT's.

It will be better than no turbo, but not as ideal as the right turbo.

The fitment of a boost compensator (BC) means that they can tune it for higher peak power (exactly the same as they could achieve without the BC) however without the low rpm / off boost smoke.

The turbo which toyota matched to the 1HD-T (essentially the same engine, just different injection and head) is too small?
Sorry, you'll have to pull the other one.

High EGT's are caused by not enough boost, turbos that are too small cause boost to come on earlier than big turbos, which reduce EGT's over the commonly used operating range. The only point where a small turbo will give higher EGT's than a large is at max revs.

Intake temps are the result of compressor efficiency, not size.

[hdj105]

The turbo which toyota matched to the 1HD-T (essentially the same engine, just different injection and head) is too small?

Well the 1HD-FT and 1HD-FTE are "essentially the same" engines too, yet no 1HD* engine runs the same turbo.

High EGT's are caused by not enough boost, turbos that are too small cause boost to come on earlier than big turbos, which reduce EGT's over the commonly used operating range. The only point where a small turbo will give higher EGT's than a large is at max revs.

Intake temps are the result of compressor efficiency, not size.

Well lets screw up the boost and see the EGT's plummet then! A tweaked 1HD-T will see boost start to drop over ~3200rpm as the turbo runs out of puff. The OP never mentioned what rpm he achieved the 630C at either.

The greatest enemy of the 1HZ is excess heat in the combustion area, adding 120C + air into the engine with more fuel won't make it happy.

[Z()LTAN]

Is it too hard to believe that car manufacturers only make things "just" good enough Kiwibacon?

If they made things fully customizable and put big expensive things on them as standard, why do we always fit aftermarket everything when we mod a 4wd?

The CT26 is "just" good enough for its intended situation. i.e 9psi and minimal fuel.

The CT26 is a cheap old technology turbo and will never perform as good as a more expensive ball bearing Garrett style turbo.

[KiwiBacon]

Well the 1HD-FT and 1HD-FTE are "essentially the same" engines too, yet no 1HD* engine runs the same turbo.

The FT and FTE engines are four valve. The shift a lot more air, hence bigger turbos.
The 2 valve head on the HZ restricts things a little more. Just like the HD-T the turbo came from.

]
Well lets screw up the boost and see the EGT's plummet then!

That's exactly how it works.

[KiwiBacon]

The CT26 is "just" good enough for its intended situation. i.e 9psi and minimal fuel.

The CT26 is a cheap old technology turbo and will never perform as good as a more expensive ball bearing Garrett style turbo.

That is exactly the situation it's being used in here. 9psi and minimal extra fuelling. Afterall we don't want to crack open a 1HZ do we?

Certainly a newer ballbearing garrett will perform better. But that wasn't the call. The call made was that it was too small. But it's not.

[Z()LTAN]

True true,

Its only too small when u want to start pushing it past 15psi or so

[hdj105]

That is exactly the situation it's being used in here. 9psi and minimal extra fuelling. Afterall we don't want to crack open a 1HZ do we?

The OP Tom stated he's already running 11psi max. How much boost do you suggest he to run to drop his EGT's?

[KiwiBacon]

That is exactly the situation it's being used in here. 9psi and minimal extra fuelling. Afterall we don't want to crack open a 1HZ do we?

The OP Tom stated he's already running 11psi max. How much boost do you suggest he to run to drop his EGT's?

At 630C max pre-turbo there's no need to drop them lower. It'll just cost you more power to pump the extra air.
From here I'd check intake and exhaust, make sure there's not an un-necessary restriction.