Actual improvement with intercooler

[NStimac]

Dougal what about the hot @$$ turbo your passing all this air through. How hot do you think it is 400-200 F. Never minding the fact that a turbo isn't 100% efficient (like your math implies). Ideal gas laws are ideal. What's happening under the hood isn't. 10psi + you will see a gain from an ic. Below that you might see a drop in EGTs but performance wise you might not be gaining anything.

[Dougal]

Originally Posted by NStimac

Dougal what about the hot @$$ turbo your passing all this air through. How hot do you think it is 400-200 F. Never minding the fact that a turbo isn't 100% efficient (like your math implies). Idea gas laws are ideal. What's happening under the hood isn't. 10psi + you will see a gain from an ic. Below that you might see a drop in EGTs but preformance wise you might not be gaining anything.

The turbo compressor doesn't pick up any significant heat from the exhaust. Mainly because the bearing core is cooled by engine oil and is quite a long path for heat to conduct along.

My maths is based on a 70% efficient turbo compressor, I have temperature measurements to back them up and since your average turbo compressor map plots from 65% to 74% it's a good figure to use.
At 15psi with the T25 I measure 115C
Calculated at 70% effiicency I get 113C

Using an IHI turbo with a damaged compressor wheel (dust erosion) 15psi resulted in over 140 deg C, the equivalent of 55% efficiency.

[MICKruiser]

Originally Posted by crushers

humm, trolling?? since when is asking a question about a statement trolling.

you said "A turbo working far outside it's best efficiency point"
and
i stated: "you are saying a company that designs turbos for particular applications is doing an improper job...correct?"

but if you can not answer the question then that is fine.

Hmmmm, good question about the conflicting ic info.

Confusing! I am thinking turbo and intercooler for my 1HZ so this is a pretty important point.

Some people saying 100 - 200 degree less EGT's and someone else saying it's a no go. . .

What's up?

[The Dude]

I think that it's just that, the efficiency of the turbo. I wouldn't doubt that we are running our turbos at less then premium efficiencies.

If you went to a shop and ask for a turbo for X truck not running an IC and asked the same shop for a turbo for X truck (the same truck) with an IC they would most likely give you too different turbos???

So I think the answer to Waynes question is yes, for the intercooled truck they gave you the wrong turbo. (or maybe just not the "best") and with those of us that see the 100-200* drops are running higher boosts then what is considered efficient for our turbos.

Clear as mud?

I belive the max boost I can get out of my turbo is 16psi and I am running it at 14. I would like to change that to a turbo that can hit 20-22 and run it at 15.

But what do I know.

[lshobie]

I think you have to work with what you have and use the closest fit that you can get. I'll take a video of the intercooler doing it's job and lowering the EGT's.

You can deal with theoreticals and actuals, the theoreticals being the perfect model and the actuals being the results of what you are using. You can keep spending money and adding more bells and whistles but eventually your gains get smaller and smaller percentage wise - and at what cost? If you have a 1HZ and you turbo it it is awsome depending on what turbo you are running, add an intercooler and you'll see more benefit, add a boost compensator and see better fuel economy and better performance, remove the air to air intercooler and replace it with a glycol/air intercooler and see better performance, chop off the stock exhaust and add a mandrel bent 3 or 4 inch pipe and see more gains, port and polish the intake and exhaust manifolds and the head and see even more gains. Get the idea?

Turbo your rig, when you can afford an intercooler add one, if you don't believe an intercooler works then do more research until you find out that it does if installed properly.

Dougal, If i use a heat detector on a turbo compressor are you saying that I will only get somewhere over 100 degrees? Not trolling - just asking a question.

[matt 105]

Originally Posted by MICKruiser

What's up?

Well, theres some first hand experience here from people who have done it, and theres some "info" here from someone who read about it on the internet.
Contact Air Power Systems (Safari) or DTS (MTQ) turbo systems who sell turbo kits and intecooled turbo kits (for the same engine). They have web sites, too.
I used to fit these, and some Dyno time, Air fuel ratio and max EGT was part of the instalation, for warrentee.

Matt

[Dougal]

Originally Posted by lshobie

Dougal, If i use a heat detector on a turbo compressor are you saying that I will only get somewhere over 100 degrees? Not trolling - just asking a question.

What boost level?
With 10psi boost you'd have something wrong to be reading over 100C in the airstream. The housing itself with probably be a little cooler than the air coming out.
With 15psi boost you'll be over 100C, up to 150C in unfavourable conditions.

The "something wrong" could be a hot air intake, damaged compressor wheel or turbo working outside the map the makers intended.
All these things result in more heat in the airstream.

I appear to be the only one here with any real measurements.

[matt 105]

Originally Posted by The Dude

I belive the max boost I can get out of my turbo is 16psi and I am running it at 14. I would like to change that to a turbo that can hit 20-22 and run it at 15.

Not quite sure what you mean by this?

[matt 105]

Will this thread make another 3 pages and then get deleeted?

[Dougal]

Originally Posted by The Dude

I belive the max boost I can get out of my turbo is 16psi and I am running it at 14. I would like to change that to a turbo that can hit 20-22 and run it at 15.

What is your turbo?
If it's a garrett then a smaller A/R exhaust housing may be available. If it's a toyota then you get what you're given.

More fuel and higher EGT's will net you more boost, but this often isn't a good idea.

[Dougal]

Originally Posted by matt 105

Will this thread make another 3 pages and then get deleeted?

If history is anything to go by............

[lshobie]

Ya Dougal that makes sense - the incoming air temps - been a long day here.

Regards,

Louis

[cruiser_guy]

Originally Posted by matt 105

Will this thread make another 3 pages and then get deleeted?

No reason to right now! We're having lively discussion, even disagreements (what a surprise !!) but no personal vindictive attacks. I have no problems here at all

[The Dude]

Originally Posted by Dougal

What is your turbo?
If it's a garrett then a smaller A/R exhaust housing may be available. If it's a toyota then you get what you're given.

More fuel and higher EGT's will net you more boost, but this often isn't a good idea.

Yup, stock Toyota on the 12H-T

[joshoisasleep]

Originally Posted by Dougal

What boost level?
With 10psi boost you'd have something wrong to be reading over 100C in the airstream. The housing itself with probably be a little cooler than the air coming out.

Bear with me I'm not sure if I've read this right. So then a good test to see whether your turbo is running outside its best efficiency would be to measure the surface temp of the pipe running from the turbo cold side to the intake manifold? Or the housing of the cold side of the turbo itself?

[Dougal]

Originally Posted by joshoisasleep

Bear with me I'm not sure if I've read this right. So then a good test to see whether your turbo is running outside its best efficiency would be to measure the surface temp of the pipe running from the turbo cold side to the intake manifold? Or the housing of the cold side of the turbo itself?

Yes. But to get a reasonably accurate reading off the pipe, you'll need to insulate it from the cooler outside air. Off the turbo housing won't give you a good reading.
Drilling a port into the pipe so you can thread a temp sensor inside is the best way, that's what I did.

[lshobie]

So - somethin glike this would be good to measure temps before and after an intercooler as well?

Digital Thermocouple Thermometer K-Type Temp High C F - eBay (item 140228574551 end time May-01-08 09:20:26 PDT)

[Tapage]

There is a device that can read the rpm on the turbo axle shaft .?

[Talos]

regarding EGT drops due to intercooling, let me quote Hugh MacInnes in his book "turbochargers"

as a rule of thumb one-degree decrease in intake manifold temperature will give a one-degree drop in exhaust temperature.

Page 88.

[Dougal]

Originally Posted by lshobie

So - somethin glike this would be good to measure temps before and after an intercooler as well?

Digital Thermocouple Thermometer K-Type Temp High C F - eBay (item 140228574551 end time May-01-08 09:20:26 PDT)

Yes, the one I have is quite similar.
I rewired my pyro probe with the same mini K type connectors (those yellow two prong ones) so I have plug and play between that and my mobile K type probes.

Tapage, there is a method somewhere on the net to use a hall-effect sensor or similar to read turbo rpm.
It'd be interesting, but it's a lot of work.

Talos, that is my point exactly. To get 200F drop in EGT's you need intake temps that can lose 200F. To get charge temps that hot at 10psi suggests something is wrong.

[lshobie]

Ah, ok, that is very interesting, and when taken literally I see what you mean, perhaps in my explanation I don't "explain" it properly. In fact it's pretty hard to explain what is heppening with the egt's unless you see it. I'll have to video it next week, but I need to set it up so you can see my rpm as well I suspect.

Where I notice the difference is when accelerating to high speed and I can see by the EGT's where the intercooler starts doing its business. At about 80-90 kms/hr with my foot to the mat the egt's stop rising (or atleast slow down very significantly) and then eventually they start to rise again when approaching the speed of sound (ok - not that fast).

Still not sure if I explain it very well. Where I see the difference and say that I am seeing a 200 degree difference is in that area of acceleration where the egt's stop rising - and where it would have been to 1200 without the intercooler. And it was a very poor way to explain it.

I can see why this is done by calculations on paper to get exacts results as there are many variables when trying to do it on the asphalt.

I'm going to buy those probes and see what mine is doing.

[Dougal]

Originally Posted by lshobie

Ah, ok, that is very interesting, and when taken literally I see what you mean, perhaps in my explanation I don't "explain" it properly. In fact it's pretty hard to explain what is heppening with the egt's unless you see it. I'll have to video it next week, but I need to set it up so you can see my rpm as well I suspect.

Where I notice the difference is when accelerating to high speed and I can see by the EGT's where the intercooler starts doing its business. At about 80-90 kms/hr with my foot to the mat the egt's stop rising (or atleast slow down very significantly) and then eventually they start to rise again when approaching the speed of sound (ok - not that fast).

Still not sure if I explain it very well. Where I see the difference and say that I am seeing a 200 degree difference is in that area of acceleration where the egt's stop rising - and where it would have been to 1200 without the intercooler. And it was a very poor way to explain it.

I can see why this is done by calculations on paper to get exacts results as there are many variables when trying to do it on the asphalt.

I'm going to buy those probes and see what mine is doing.

What is the boost level doing in that situation?

[lshobie]

If I have my foot to the floor the boost is pinned at 12 pounds.

[The Dude]

That is very similar to my situation as well except I am running 14psi boost.