quick garrett turbo question... opinions

[joshoisasleep]

OK this is really sweet. He didn't have gauges that matched my temp range so he's sort of making one up for me. He said he can do me a dual instrument that will display EGT on one side and air inlet temp on the other side... very cool!

What temperature range is best? 500 degree F range. My guess was going to be 800F - 1300F on the EGTs, and 0-500F on the air in.

What do you think?

 

[cruiser_guy]

OK this is really sweet. He didn't have gauges that matched my temp range so he's sort of making one up for me. He said he can do me a dual instrument that will display EGT on one side and air inlet temp on the other side... very cool!

What temperature range is best? 500 degree F range. My guess was going to be 800F - 1300F on the EGTs, and 0-500F on the air in.

What do you think?

My Isspro pyrometer has a range from 100 - 1500 F. For air in, post compressor, I'd think no more than 300 F, more than that and an intercooler would be really useful.

 

[joshoisasleep]

wow I hope you never use the full range of that Pyro... my understanding was that at 1350 you've melted something already...? Hmmm I've got to choose within a 500 degree range...

 

[wesintl]

500 is too broad on temp. 240 or 250 max is what you want so you can see the temps swings better. My pyro is 0-1600. which is a good range. 1500 is fine too.

 

[joshoisasleep]

500 is too broad on temp. 240 or 250 max is what you want so you can see the temps swings better. My pyro is 0-1600. which is a good range. 1500 is fine too.

I'm really confused. You say 500 is too broad, and yet 1500 is good? I'm assuming there's something I don't know about gauges here...

 

[Dougal]

In metric you want 200-800 deg C.
That works out to 400-1500F.

200C is a safe shutdown temp, 750C is the highest you ever want to see.

 

[wesintl]

I'm really confused. You say 500 is too broad, and yet 1500 is good? I'm assuming there's something I don't know about gauges here...

up to 250f for water temp. 0-1500f for pyro

 

[joshoisasleep]

Damn, I think that puts me back at square one since he said 500 degree temp range... good for the intake but not the EGTs. That sucks cause I was really stoked on the awesome dual-instrument! What do you guys think of the technique below?

One thing you could do is convert the milivolt output from the thermocouple with a multimeter and then convert it to temp from a conversion chart. Yeah, a multimeter duct taped to your dashboard!

 

[jzilla]

I have an 81 BJ60, I had mine recored.
Definitely get a 4 row rad if you can.

 

[Otterav]

It's interesting that other users of the Supra on the 3B don't reach 15psi boost till about 3000rpm (which you'd expect).
Yet with a very similar setup you're claiming the same 15psi boost arrives at 1900rpm.
IH8MUD.com Forum - FJ to BJ mutation?



IH8MUD.com Forum - school me in turbo tech for the 3b

I don't know what you would expect, other than being wrong more often than not. I am not "claiming" anything just stating fact, as evidenced by two other mud members.

How do you explain a difference this large?

Once again, I had those same numbers until I adjusted my fuel settings. Everyone has their own settings that they prefer, I guess it's hard being wrong, get over it!
eric

 

[BillyGHusk]

here we go again......

 

[gerg]

Otterav, what kind of Exhaust Gas temperatures are you seeing at those RPMs... 1200, 1500, 1800 etc? Like if your climbing a hill in 4th and are stuck with slow acceleration. I could see how you can get great boost at lower rpms, I would only worry about Temps.
Later
G

 

[Otterav]

Otterav, what kind of Exhaust Gas temperatures are you seeing at those RPMs... 1200, 1500, 1800 etc? Like if your climbing a hill in 4th and are stuck with slow acceleration. I could see how you can get great boost at lower rpms, I would only worry about Temps.
Later
G

Hello,
I limit my EGTs to 1100F post turbo, and only for transients(few seconds), if the EGTs are climbing I use the gearbox and skinny pedal to regulate the EGTs to my 900F or so, increasing RPMs cure EGTs quickly and effectively. I have come to the realization that this is not a 3208 Cat w/500 HP. and drive with that in mind.
Hola
eric

 

[BillyGHusk]

Hello,
I limit my EGTs to 1100F post turbo, and only for transients(few seconds),

Do you have any idea/thought what they are pre turbo? How far is the probe "post turbo"?

Just curios, trying to learn.....

Tim

 

[Otterav]

Do you have any idea/thought what they are pre turbo? How far is the probe "post turbo"?

Just curios, trying to learn.....

Tim

Hey,
I was talking to Banks Engineering, back when I was turboing(in the early 90's) my 2 1/2 ton military truck, they estimate that the average drop across a average turbo was 250F. My probe is about 1" from the turbine wheel face.
Hola
eric

 

[gerg]

That is some good info, thanks Otterav.
G

 

[Dougal]

How much lag a probe has tends to impact the readings greatly.
I haven't seen one yet that can give an accurate result under acceleration, I've even had some which would keep climbing whole seconds after your foot had been lifted.

 

[cruiser_guy]

How much lag a probe has tends to impact the readings greatly.
I haven't seen one yet that can give an accurate result under acceleration, I've even had some which would keep climbing whole seconds after your foot had been lifted.

The Isspro that I have on all my trucks is pretty quick in responding. It certainly doesn't keep increasing after the skinny pedal is lifted.

 

[Otterav]

How much lag a probe has tends to impact the readings greatly.
I haven't seen one yet that can give an accurate result under acceleration, I've even had some which would keep climbing whole seconds after your foot had been lifted.

it is really quite simple, the undersizing of the turbo causes the superheating of the intake charge. This causes the intake and the related plumbing to be superheated.This is usually caused by faulty engineering principals and not understanding turbocharging fundamentals. This is also caused by "engineering" ones own components from used cooking oven components. Vodoo engineering, only works in the mind of the one who practices it.
eric
Bet this one only makes it an hour or 2!

 

[gerg]

I personally do a bit of column A and a bit of column B. If you are able to keep your EGTs in the safe zone during slow, hard acceleration, then I don't see a huge problem. I can see how if it is fast acceleration, like off a stop light, your probe would be a second or two behind.
Thanks
G