Engine/Transmission (1998.5 - 2002) High pyro temp

[Blademan]

Hey guys,

I finally had some work done on my truck...head gasket, etc. So while the shop had everything apart I figured it was time to add the 275's and a Smarty. I do use the truck to tow an enclosed trailer that is maybe 8000lbs. I've noticed it doesn't take much time pulling a hill and the pyro is up to 1200. So is it time to look at doing some turbo work also? I've been reading one thread and going to a bigger turbo hx40? isn't a good idea yet. Or do I just have to run a lighter setting on the Smarty? The shop said they set it on #7.

My mileage increased by at least a couple MPG though, so that was nice.

Any ideas? Thanks.

 

[BDaugherty]

1200 is ok as long as oil and coolant temps dont get out of hand. I would just lower the smarty a couple levels.

 

[JR]

You should not need a larger turbo for that set up. Lots of variables that will cause higher egts. Did you have a gauge prior to compare numbers with or was it added with the injectors and smarty? Which transmission do you have? What size tires? What gear ratio? How steep of a grade are you talking when you start seeing 1200*? Reason I'm asking is all of this and the way you drive plays into egts. You have alot more fuel being added to the equation, so one thing you can do that will help when the engine is under heavy load is use a lower gear. Instead of lugging the engine at 1700-1800 drop it down a gear and run higher rpms.

 

[cerberusiam]

What is boost at when you hit those temps, that will tell you if the turbo is out of its map? If the 1200 is max you are fine as you can run up to 1500 for 3 minutes out of 5 and usaully be fine given everything else is good.

Normally, the Smarty gets set on 9 and the temps are controlled with the rigth foot or air upgrades. If you like the power and you are pushing it to around 1500 at times to maintain speed a bigger turbo should help. An HX40 is old technology, you want about the same compressor size but a smaller turbine or it will be slow spooling. A 60\12 or 62\12 turbo would be a good addition for more air.

 

[Blademan]

Thanks for the replies.

When the truck was stock I had the gauges installed and it might get to 1200 on a very long hard pull, but it wouldn't really go over that. Plus if it did, I would just grab a lower gear. Boost would max out at about 21 when stock.

Now the pyro will exceed 1200 in a short amount of time...(45 seconds maybe) on a 6% grade as an example. Boost is now topping out at about 23 or 24. They did install ARP head studs too. I do like the power and mileage now and would like to find a solution.

Truck is an 01 245 HO QC 4x4 dually. 6-speed manual, 3:54 ratio with stock size tires, upgrades have been 4" MBRP exhaust, autometer gauges pyro, boost, and fuel, ARP head studs, RV 275's Smarty on #7, South Bend Clutch

Thanks everyone!

 

[cerberusiam]

Can you control EGT's by gearing down? When the EGT starts rising is it a steady throttle and just the grade? Does it hold speed easily or do you have to push it?

On that much grade with a load you are probably starting to run short on air in certain conditions. If you can drop to 5 and EGT's stay in check it is just a matter or rpm's. If the EGT's keep climbing with more rpm's it is out of air.

 

[NIsaacs]

With your mods you should have about 30-32 psi boost. I don't know anything about a Smarty, does it have a boost fooler of some type? Your boost of 23-24 is low. Your temps will go down if you can find out why you can't get higher boost numbers and fix it. Boost leak somewhere or waste gate stuck open a little?

Nick

 

[PC12Driver]

The Smarty does do boost fooling. A "boost elbow" should get you around the 30-32 psi that Nick mentioned and drop the EGTs back to a comfortable range.

A boost elbow (such as this one from Source Automotive) is basically a controlled leak that delays the opening of the wastegate. It replaces the stock elbow that screws into the compressor housing and plumbs into the hose that supplies boost pressure to the wastegate. Adjust it to the low 30's and you'll be good to go. Figure on a 50-100* egt drop from what you see now.

P.S. Above about 35 psi the stock HX35/12 will turn into a hair dryer and your egts will begin to spike pretty quickly. 32-34 psi would be a good target.

 

[Blademan]

I am not able to control the high temps by dropping to 5th gear. It will still climb to 1200 pretty quickly and beyond. The only way I've been able to control the temps is by dropping gears and backing out of the fuel. I will look into some of the items mentioned. Thank you for trying to help!

 

[cerberusiam]

Don't think you can use a boost elbow on that turbo so it will be a j-hook to hold the WG shut, but, by the time you get to 30 psi the turbo is out of its map anyway. It will help but you will still suffer at lower rpms trying to load the engine. It might get you what you want so at least try it.

A good turbo will give you more air at 20 psi to control EGT's than the stocker ever will at 30 psi so you are on the right track thinking turbo time. Smarty doesn't boost fool but nless you are getting over boost codes it is a non factor.

 

[NIsaacs]

Don't think you can use a boost elbow on that turbo so it will be a j-hook to hold the WG

The OP has a 6-spd truck. I have been running my '01 for the last 180k with my mods @ 30-32 psi boost, pulling hard, foot to the floor, 1700-2300 rpm with no ill effects. Under 1700 or over 2300, then yes, temps are a problem so I don't do it.

Nick

 

[PC12Driver]

Don't think you can use a boost elbow on that turbo so it will be a j-hook to hold the WG shut, but, by the time you get to 30 psi the turbo is out of its map anyway. It will help but you will still suffer at lower rpms trying to load the engine. It might get you what you want so at least try it.

Negative. That's the exact truck that I used to have. It has an HX35 with the rubber boost hose and an elbow. The turbo on the auto trucks that year (HY35/9) have a hard line and need the j-hook.

The tiny HYs were good for the high 20s. The HXs had no problem giving beneficial boost to right around 35. After that the pyro would climb sharply, so it was pretty obvious where that turbo's limit was.

I ran that fueling level for a couple years with that turbo and egts were no problem with 34 psi at the manifold and a 10k lbs 5th wheel in tow.

 

[JR]

I have the exact same set up and have had no problems pulling similar grades. The boost elbow will help, but the one major difference I'm wondering about is elevation. I'm much closer to sea level, if your at a high altitude going to a larger turbo may be your best bet.

 

[PC12Driver]

A larger turbo killed my power at altitude, and egts were uncontrollable unless the engine was well into the 2,000s. Big turbos don't make more air, they just move larger amounts more efficiently if adequate drive energy is available. At altitude that drive energy isn't there. Even the little stock turbos suffer on the bottom end. I was cut off on an 11,000' pass and had to hit the brakes, and the Hx35 wouldn't even wake up until 1,600 rpm or so. I had to drop all the way back to second to light things back up and accelerate. The hybrid I had would have needed about 2,000 rpm and egts would have been at or near redline by then.

 

[NIsaacs]

I have the exact same set up and have had no problems pulling similar grades. The boost elbow will help, but the one major difference I'm wondering about is elevation. I'm much closer to sea level, if your at a high altitude going to a larger turbo may be your best bet.

You don't get no cigar! Anchorage, AK is 102' so....

Nick

 

[JR]

You don't get no cigar! Anchorage, AK is 102' so....

Nick

HA! Guess that shows how much I know about Alaska! Stupid midwest farmers...:-laf

 

[Blademan]

Yeah...I'm in Anchorage Alaska. So most of the elevation the truck will see is 0 to 3000 feet. I haven't even left town yet, so it has not seen 1000 feet. The pyro temp sensor is mounted pre-turbo also. No trouble with water or oil temp. Outside air temps might have been about 40 degrees max on the few trips I made with it after getting it out of the shop in the morning and early afternoon. I've only had it out of the shop for a couple of weeks so I don't have a lot to go on yet. I need to get a video one of these weeks and put it on YouTube of what's going on.

Thanks!

 

[Bob4x4]

Make sure you don't have any boost leaks that will make temps much hotter than you should have at your power level

 

[cerberusiam]

An HX35 is well out of its map by the time it gets to 30 psi, can't ignore the numbers and THAT is fact. Holeset builds these turbos for the application and that is stock power. Yes, they will boost over the stock map. Yes, they will make power over that BUT they are beyond their useful range.

A bigger turbo WILL make more air. A bigger turbo WILL make more air at lower boost than an HX35. A bigger turbo will not spool slower, raise EGT's, or anything other than provide the air needed for the fueling. The biggest problem is the buyers are so undeducated about what turbo and how they work they end up buying the marketing glitz instead of doing their homework and finding a match for the application. Home work is essential or you are buying someone elses idea and it likely will not work as well as expected.

Add the boost elbow, j-hook, whatever it takes to raise the boost to see if that will solve your problem. If it gives you adequate control over EGT's and you can run the power level you like you are on your way. You should be able to get it to 30+ psi with some rpm. Whether it will keep EGT's in check where you want to tow is another question. If you want to tow at 2000 rpms and it takes 2600 rpms to keep the temps where you want, then you have choices to make.

 

[NIsaacs]

An HX35 is well out of its map by the time it gets to 30 psi, can't ignore the numbers and THAT is fact. Holeset builds these turbos for the application and that is stock power. Yes, they will boost over the stock map. Yes, they will make power over that BUT they are beyond their useful range.

I am going to respectfully disagree with this blanket statement. The HX35 is not out of it's map at 30 psi at all RPM ranges, my miles driven and pyro numbers prove that it is useful. To say otherwise would be like saying my stock steering shaft will not drive my truck, that I need a Borgeson. I have never run off the road with my lil old stocker shaft

Nick