pyro temp hotter after fitting intercooler How, Why?

[MQCRAZY]

Ok so heres the story I've got a GQ TD42 with an older style dynamic turbo kit with the switzer high mount turbo kit. Standard fuel pump wound up running 15psi. Before fittng the cooler my pyro would max out at 530c post turbo probe is 25mm from the dump flange. After fitting the cooler which is 450x300 bar and plate top mount sealed to the bonnet under a
D40 navara scoop with a 12' thermo drawing air through from underneath. First drive my pyro hit 560c really quickly so pulled a full half a turn of fuel out pyro will still make 550c on a big pull. Also now even with my wastegate tied shut I can only just make 15psi by 3300rpm. Suspected a boost leak so put a second boost gauge on my wastegate line and it is reading within half a psi of the guage plumbed into my piping close to the plentum.So is it possible that my turbo is so inefficiant that it just cant push enough air to fill the coolr and make decent boost?

Cheers Gary...

[nissannewby]

When you intercool as your cooling the air and making it less dense you are reducing the pressure of the air so you either need wind more fuel out of it or push more boost. It could be your whole combo that isnt efficient enough, your pump maybe at its max and cannot produce enough fuel to make decent boost and your turbo may also not be up to the task now that you want more from it.

[gu town]

When you intercool as your cooling the air and making it less dense you are reducing the pressure of the air so you either need wind more fuel out of it or push more boost. It could be your whole combo that isnt efficient enough, your pump maybe at its max and cannot produce enough fuel to make decent boost and your turbo may also not be up to the task now that you want more from it.

Nope.


More dense.


which means more oyxgen for the same PSI. more oxygen means you need more fuel. too much or not enough fuel means extra heat. in your case not enough. IMO

Just a guess but your turbo working harder to keep up with the same PSI. You may well have it working too hard to be efficient.

[tweak'e]

........with a 12' thermo drawing air through from underneath......

just to be clear. that reads like you have the fan blowing air from engine through IC and out the bonnet. which of course would heat the intercooler not cool it.

see if you can fit boost gauge before and after intercooler. see what the drop is. IC could be blocked or just crap.

[GUtripper]

Sure I saw something on the Pootrol forum a while back about IC fans...... under (or in your case on top of) the fan motor no air flows and creates a hot spot in the centre of the IC. Additionally, at speed the fan may actually restrict air flow through the IC, creating heat, therefore less dense air and a richer burn.
Get rid of it and see if that gives a positive result.

Otherwise, high EGT's generally mean insufficient air to burn fuel.... could be your IC piping is too big or too small, either restricting boost (pipes too small) or creating a drop in boost if too big.

Sure there's not a vaccum or other leak post IC, ie a vaccum line off the intake manifold?

[MQCRAZY]

thanks for the replies guys. just to be clearer my fan is mounted underneath the intercooler drawing the air through the bonnet scoop into the engine bay.The piping is 3" but only 2 short 180 bends so I dont think it should be the problem. I have noticed also my pyro temps are staying hotter on idle down before intercooler my pyro would drop very quickly to about 150c now stays up near 200c. could this be because of not enough fuel?

[gu town]

could this be because of not enough fuel?

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

[marty]

could this be because of not enough fuel?

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

If all he has done is add the cooler then the tune should not have changed that much.
You have a issue somewhere.
Either you have a boost leak, or the intercooler is very restrictive.
You may not be getting enough airflow through the cooler and it heat soaks.
First of all were does the wastegate line run from? Pre intercooler?
If so change that first to post cooler, and see what it does.
It really does sound like a lack of flow though.
To eliminate anything else remove the cooler and see if it goes back to the way it was before.
No need for a professional tune if it was fine before hand.

[tweak'e]

i'm picking you have a blockage or a leak.
i know someone who'se egt temps went way up. turns out he had dropped a rag into the intercooler.

[Skegbudley]

could this be because of not enough fuel?

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

Completely the opposite actually. EGT temps will drop with more boost and less fuel.

I'm thinking either a blockage in the intercooler or a boost leak.

[GUtripper]

The delay in egt's dropping will probably be either linked to a too rich mixture, or the top mount being a heat soak when the car isn't moving, hence high intake temps and high exh temps.
Or a combination of both.

Pay a couple of hunge and get it dyne tuned properly, by a professional, and set the fuel ramp and delivery. It can't hurt, and you'll probably end up with more power and better economy too.

[Clanky]

If you were to use the old rule of thumb that 1 deg increase (or drop) in intake temp = 1 deg increase (or drop) in the exhaust it stands to reason that your intercooler is not doing its job, and is possibly working opposite (adding heat to the intake air)

I think the give away that your cooler is absorbing heat and not losing it, is that it is running so much warmer at idle (no boost and minimal fuel).

Easy way to check, is to measure your intake temperatures before and after the cooler.
If the temps are higher on the outlet side of the cooler then you have an airflow problem (internally or externally). Initially you could use your hand to gauge the temps to see what is going on.
A good cooler should be much cooler on the outlet side after a run

Start with the basics. Dont get a tune or anything else done till you get it sorted. You may introduce more problems

If the cooler system is working effectively then adding it to the motor (without any other mods) will drop exhaust temps, not increase them.

Do you have a rubber gasket flange arrangement to seal the top of the intercooler to the bonnet so its not sucking hot engine bay air across the cores?

[gu town]

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

Completely the opposite actually. EGT temps will drop with more boost and less fuel.

I'm thinking either a blockage in the intercooler or a boost leak.

I was under the impression too lean AND too rich will increase EGT's?

[UGOTNUFN]

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

Completely the opposite actually. EGT temps will drop with more boost and less fuel.

I'm thinking either a blockage in the intercooler or a boost leak.

I was under the impression too lean AND too rich will increase EGT's?

NO.

Sounds to me like the intercooler is junk or you have a boost leak.

To say you have taken fuel out to reduce EGT's after an intercooler fit really suggests that it isnt working at all OR the compressor end doesnt have the ability to deliver , pressure is pressure and volume is volume, dont confuse the two as they dont go together.

EGT' is the result of a fire , if you take away the fire then you will take away the heat. A diesel is in a lean condition (compared to a petrol) 85% of its life, so more fuel will increase EGT's and less will reduce them.

MAtt

[Judge]

Hay mate How much black coal does her blow out the rear ????? I put a PWR front mount on mine and did not have a problem cheers Rick.

[Skegbudley]

I reckon so. I'd wind the fuel back up and drop the boost a little. OR stop guessing and get it professionally tuned.

Completely the opposite actually. EGT temps will drop with more boost and less fuel.

I'm thinking either a blockage in the intercooler or a boost leak.

I was under the impression too lean AND too rich will increase EGT's?

It depends on whether you are talking about diesel or petrol.
Petrol engines run hotter when you lean them out and cooler once you add fuel.
Diesel engines run cooler when you lean them out and hotter once you add more fuel. Adding more boost to a diesel engine will reduce the EGTs.

[MQCRAZY]

So heres a bit of an update pulled the cooler and piping off checked for any blockages, couldn't see anything. Blew 120psi of compressed air through the cooler and it seemed to flow out the other side well. Put it all back together and siliconed all the joins in the piping.
Took it for a run and it is slightly better.
Temps now are 50ks 3rd gear 2psi 200c- 50ks 4th no boost 180c
Highway cruise 100ks 5th gear 4-5psi 320-340c
Top gear up hill pull 100ks 10-12psi 510-530c
Are these similar to what others are getting?
The main theory I have at the moment is the turbo is making boost so late that it cant burn the fuel cleanly down low which is quickly heating the EGTs then by the time it finally makes decent boost its to late and the cooler is struggling to cool it back down. Could this be the case or am off track in my thinking?
Currently have my wastegate locked shut and am still maxing out boost at 16psi and only making that after 3000rpm
Cheers Gary...

[nissannewby]

Seems high for an unloaded vehicle. My GQ running 14psi uninterccoled sits on about 250 cruising on the highway 5th gear at 100. My GU which is our tow vehicle is running 14psi with a little more fuel and with a 2T+ trailer behind it sits on about 350 cruising on the highway. It sounds like your setup isnt quite cutting for what you want to do your turbo might be making 16psi but its struggling so much to do this that its heating the air right up in turn making your intercoolers job harder.

[tweak'e]

whats the pre turbo intake side of things like ?

got any pics of the setup?

[MQCRAZY]

Has a safari snorkel standard air box with unifilter then 3" piping to the turbo. I have removed the intake piping taken it for a run to make sure it wasn't too restrictive made bugger all difference.
I do have some pics but can not work out how to get them to upload happy to send them to someone who knows how if anyone is willing to upload them for me.

[GUtripper]

I recently got my rig tuned and spent a lot of time talking with the tuner as he was running it up on the dyno multiple times.

Just because your turbo is pushing 16lbs of boost doesn't mean it's a good thing. It may be actually spinning in excess of it's design parameters, and in doing so being very inefficient and creating excessive heat. Turbos can typically spin anywhere from 70,000 - 120,000 rpm...... If it's at the top end or even beyond this range it's doing so with a lot of heat created, which even a very efficient intercooler will have trouble reducing.

I said it before, but again....... Get it tuned on a dyno. It may be too much fuel, an air leak post turbo, restrictions either pre or post the IC, or too much boost for the turbo. You may find winding down boost by 2 lbs reduced EGT's quite a bit, whereby you can actually wind up the fuel and make similar or even more power, and fill flat spots in the power delivery in the process.

[300WinMag]

Those switzer high mounts are crap, the compressor is too small creating a restriction, and the exhaust housing too big and inefficient, too slow to spool up, they sound like there working hard but actually not producing enough flow to create pressure. Restriction to flow creates pressure; therefore if the turbo can't keep up with the engine it will not produce good boost pressure until it’s in the top end of the rev range when exhaust gases are driving the windmill efficiently.

A better matched turbo and pump setup will produce the same hp with less fuel and lower egts.

The why; because you have increased your plumbing size to 3" plus the volume of your intercooler, you have created more lag, therefore higher egts as your engine is running richer even though you have the same fuel setting. Your IC will also have a CFM rating, if this is too low it will also be restricting airflow, but by the sounds of things its a turbo problem. Reduce your plumbing to 2 1/4" and this will increase air velocity, but if your IC is of a high volume you will have to upgrade your turbo setup anyway.

[MQCRAZY]

thanks again fellas your replies are all helpful.
I wish a dyno tune was an option but the nearest tuner I know of is in Brisbane which is 4 hours away and even so I only have a standard pump with no boost compensator so the tuner would be very limited in what he could do in regards to fuel ramp and delivery.
Winmag300 if my switzer is rubbish which is what I was suspecting what turbo would you recomend I have been looking into GT2860s with .64 hotside and a T3/T4 hybrid with a .50 intake and .63 hotside I am not after huge power and never plan on taking the boost over about 18psi because I dont have the spare coin for a big pump.
Everyone else feel free to add your opinion to what turbo could be best for my needs the more input and info I get the more chance I have of getting it right the first time.
Cheers Gary...

[300WinMag]

The GT2860s would be a good matchup, great down low boost and torque from all accounts, haven't used one myself, I have built myself a hybrid from bits and pieces and had it balanced too 160k rpm, good for 30+ psi and still produces 10psi @ 2000rpm, 24psi @ 2500rpm.

Ugotnuthin could set you up with a good Mitsubishi TDO5H matched to your requirements if you PM him.

[Judge]

Hi HQCRAZY What do you use your truck for? what to you tow? How much power do you need??? I have a GQ wagon with a garrett T3 highflow turbo running 12psi put a 01 injector pump in it PWR front mount and 21/2 tubing sorkel etc and it puts out 160hp at the rear wheels and it does do every thing i need to do!!

[marty]

Lets back track a little.
Before you put the cooler on, were or when did you hit max boost?
Just blowing 120psi through the cooler is no indication of anything.

[MQCRAZY]

Sorry I should have explained myself better with the blowing air through it I capped both ends with the plastic caps that came on the cooler pushed an air fitting through one end then opened the valve on my compressor the cooler quickly pressurized and blew the opposite end cap off to the one I as blowing air through.
The turbo has always only made max boost at over 3000rpm
Doing 100ks on the highway if I floor it it'll only make 8 psi that was the same before the intercooler went on its always been crap.
Thanks winmag I'll see what ugotnothin charges for a turbo my budget is a bit limited has anyone tried the eBay GT2860 copies or am I bound for trouble going a non genuine turbo?

[MQCRAZY]

Hi judge my plan for the truck is to use as my daily driver and touring rig will be towing a camper when I get one and a car trailer with a commodore on it every now and again. The main reason I intercooled it is I am trying to get the truck ready for a Fraser trip I have planned for later in the year and thought I would need all the help I could get keeping it cool on the sand that's also the reason for top mount not front mount didn't want anything else blocking flow to the radiator.

[tweak'e]

the cheap copies are still a mixed bag. quite a few people getting good ones but they still have bad ones.
i got a cheap one in for my toyota and it lasted all of 8 months and its only a 2nd vehicle.
considering the places you go i would just spend the $$$ on something you know is going to last.

have a look on patrol forums there is plenty of write ups on turbo's. i think the gt2860 was on the small side. they tend to go rather inefficient at high boost. but provided you don't widn the boost up to much it sounds like it will be far far better than what have got. don't take my word for it, have a look around theres tons of write ups on different setups.

[Judge]

May be try your intercooling pluming with 2 1/2 tubing instead of 3inch ????? may try ebay for a second hard PWR off another car and make it fit just an idea cheers Rick.