Engine/Transmission (1998.5 - 2002) Still need help w/ EGT's

[jlccc]

I have the modifications as listed in my profile. Towing my 5500# TT uphill (@ 5K-7K feet) I can still hit 1400+F if I keep my foot in it. I'm in a dilemma as to what I should try next to keep temps down. My goal is to get enough cooling so I don't have to worry about EGT's no matter how deep I put my foot.



I'm considering the following:



1)PDR HX-35 w/ 14cm2 wastegated housing



2)14cm2 wastegated housing by itself



3)AFE Megacannon



4)Having the local Holset distributor change the 54mm wheel in my HX-35 to a 56mm or 58mm wheel.



[I would try a 16cm2 non-wastegate housing except that I can't, due to the Jacobs exhaust brake not fitting on that particular turbine housing. ]

I'd be grateful if someone with REAL EXPERIENCE, not heresay, could chime in on this.

 

[Koa Man]

I had a PDR HX35/14, which gave me about a 100* drop from the stock turbo with quicker spool up and more boost. I could still hit over 1400* real easy. Changed to a HX40/16 and EGTs dropped another 200*. I can keep my foot in it pretty good now. I feel this is all the turbo I need with my current mods.

 

[Greg Boardman-RIP]

I think that the problem in your case is not the air filter. The Mega Cannon will not flow much more than the BHAF. I have DDII's, BHAF, DD DRAG Comp box, and a HX40. I can still see temps of 1250* towing in the desert heat (110*) uphill loaded with trailer full of horses holding it WOT. Engine temps raise too. I also am running the 180* stat and it helps a little. My best advice to you is to lessen up on the throttle. That is what I have to do. I will also run at 60 mph in third to keep up the boost. With the fuel you are pushing, I would say the advice of a hx40 is not the greatest. I would maybe get a hx35 modified by Piers to do the trick. he says that the 40 is for trucks with 350 hp or more. If you wastegate the 35 at about 32-34 psi it will be in the optimum efficincy range. That will help. Now the thing about being able to keep your foot in it without worrying is insane. The only thing to cure that seems to be alot of money. Then you need Twins, bigger injectors, Comp box, ya see where I am going here? I would stick to what you have and maybe lessen up a bit. 1250-1300* is very acceptable in my book. You are not very far off from that. I also suspect the bombing bug might have hit. If so enjoy Hope this helps a little. Greg

 

[jlccc]

Originally posted by Greg Boardman Now the thing about being able to keep your foot in it without worrying is insane.

[snip]

I would stick to what you have and maybe lessen up a bit. 1250-1300* is very acceptable in my book. Greg

No, the bombing bug has run its course. I don't need or want any more power, I just want to be able to use what I already have.



Perhaps my expectations are a little high. I was under the impression that with just an EZ, 275's, BHAF and 4" exhaust I might be able to stay under 1300F at WOT.

 

[Greg Boardman-RIP]

I think you should be able to haul uphill WOT most of the time. I would downshift when the goin' gets hot.

 

[jlccc]

Originally posted by Greg Boardman

I think you should be able to haul uphill WOT most of the time. I would downshift when the goin' gets hot.

I think I should be able to also. But I can't.



Say I'm doing 70 mph up a hill. If I stay in sixth with the throttle nailed, EGT's climb slowly to 1400+. If I put it in fifth then I reach 1400F MUCH QUICKER. Downshifting doesn't help.

 

[KatDiesel]

You have neglected to mention what your boost numbers look like?





A PDR HX35 w/14cm² housing will prolly be the most exspensive option. Since you already stated you want to keep your Jacobs brake, I would try just a housing swap. If that doesn't do enough for you then you could add the PDR HX35 to the mix? If you don't mind going straight to it (money wise) from the getgo... ... try the PDR HX35... ...

 

[Koa Man]

What KatDiesel suggested is a good option. You won't be out any money if you added the PDR HX35 after you bought a different housing, since the cost of the turbo shown on Piers website does not include a housing.



I also wasn't suggesting you get a HX40 either, since I know you want to keep your exhaust brake. Just letting you know that the HX35/14 was not enough in my case. My flatbed headboard, 5 ft. high, is killing my truck's performance at speed. On my test hill with the HX40, truck empty, I can only do 72 mph @ 1250*. Before I changed over to a flatbed, I could do 80 mph @ 1300* with the stock turbo. My next mod will be some air flow modifications to my headboard.

 

[jlccc]

Originally posted by KatDiesel

You have neglected to mention what your boost numbers look like?

Boost numbers vary a bit with my foot of course, but at max boost I can hit 29-30 psi, even at 7K elevation.



If I nail it I see 29-30 psi. When I back off the throttle to maintain 1300F, I have to admit not paying real close attention to the boost I'm getting at that very second. (I've always been more concerned with watching the pyro). I believe I recall seeing about 25psi though while maintaining 1300F.

 

[JMarkos]

jlccc, I am in the same boat as you are, maybe its the crappy Utah air. Up until this spring I had never hit over 1200, but it seems , or everyone is telling me that the hot summer air will add 1 1/2 times the outside temp to your EGT's. Maybe so but I never had this problem last year. I don't know how hot mine will actually get as I don't want to become my own warrenty station just yet, but I have seen 1400 and it was climbing fast. I would be interested to know what a bigger pin wheel would do also,I am considering that and a non wastegated 14cm.



I assume you have checked all your hoses and clamps for an air leak, I made a set of plugs and pressure tested mine, if you want to use these you are welcome to them.