Turbo Manager questions, help me beat a dead horse.

[great white]

Yes I know it's been posted a thousand times. I've been reading posts all night.

I'm a proponent of using the stock vacuum system on my truck. I like it and the tunability it offers.

But I've read a post by Simon where he put a homemade TM on his 98 (http://www.thetruckstop.us/forum/showthread.php?11102-TM-results-and-other-observations-questions) and it's got me rethinking things.

The main thing that drew my attention was the reduced egt's when hauling around 7000 lbs on grades of up to 7%. Now, keep in mind, this was his fresh rebuild. My old hoss has somewhere around 350,000 kms on it....

With my upcoming tow through the rockies with the 7500 lb TT, I'm finding myself doubting the stock vac system and it's ability to control egt's no matter how I tune it. Especially after my recent high egt experience on just a few road "dips" pulling the trailer.

So, as mentioned, I'd like to beat a dead horse with pro's and con's for a TM please (feel free to copy the list and add):

Pro:

Linear boost curve
Less moving parts
Better EGT control?


Con:

Loose of fine tunabilty
MPG decrease?



Help me decide either way guys. An ATT is just too far outside my budget right now with the need for exhaust and maybe a Heath PCM in the very near future.

Oh yeah, one more thing:

I'll either spin up a copy of the Heath TM on the mill or just buy one from him outright for my GM8....

 

[ak diesel driver]

I believe he got lower egts as compared to a stock tune. The stock tune really sucked as far as boost goes. When your towing heavy up a hill the pcm would pull the boost right when you needed it most.

 

[great white]

I believe he got lower egts as compared to a stock tune. The stock tune really sucked as far as boost goes. When your towing heavy up a hill the pcm would pull the boost right when you needed it most.

Interesting.

My vac system holds around 7-8 psi when loaded up and keeps it there but still likes to spike 1000-1200. It would go higher if I let it.

I'm just looking to keep the egts down.

Current plan is a 4" exhaust and I still have to hook up my devils own kit.

I am considering a TM and a "t-series" Heath PCM to try and further reduce
Egts.

Of course, getting rid of the 350,000 I'm vac pump would also he some piece of mind onthe 8000 I'm haul I've got ahead of me....

 

[great white]

Umm, just browsing Heaths site and found this about a shorter belt:

belt used to eliminate the vacuum pump on 96-00 model 6.5's & will not fit vehicles equiped with OE vacuum pump.

Am I stuck with running the vacuum pump as some type of idler pulley even if I install a TM on my 98?

That would kind of negate any increased reliability or incremental fuel savings from doing a "pump-ectomy"...

 

[JiFaire]

A couple of things, BJ -

The debate over 'to TM or not to TM' has been ongoing for quite some time, now. You can listen to it all over again, but:

- those of us with a TM and Heath tune experienced FAR better towing performance with respect to both power and EGT control.
- most of us also reported better fuel mileage when towing. Few reported losing MPG when empty, although the vacuum proponents claimed that we must be getting much less. All I can tell you is my mileage stayed the same empty and increased while towing, as measured over thousands of km in both trims.

Take that for what it is - I am not that interested in the 'theory' behind it, and I could care less about 'converting you' to my way of thinking. Those are the real-world MPG facts as I saw them.

Secondly, you can remove the vac pump and run a shorter belt on your unit. Heath's disclaimer is there because people were buying the shorter belt and trying to put it on trucks WITHOUT removing the vac pump. (yeah, I know...) I left mine on because I'm basically lazy. In your case (even thought you aren't lazy) I'd leave the pump and lines intact so you could change it back (to vac control) if you wanted to keep experimenting with vac. control.

I have seen all kinds of 'knock-off' turbomasters built, and am just not convinced that they work the same as a real one... the length of the wastegate arm lever, the pitch and rate of the spring used, etc have been very different and I am not convinced they work as well. I asked Bill about that once and he said it took a long time and a pile of real-world testing to get the variables all right; he figured people were free to build their own, but his worked the way it was supposed to - predictably and properly.

I tend to agree with him on that.

Here's a thought; you can always drive through Ellensberg on your way east; make advance arrangements to stop in and see Bill and Todd and get some work done.

 

[great white]

Thanks Jim.

Real world experiences are always valuable.

I'm kind of in the same boat as you right now. I'm more focused on just getting it to work more than the theory behind it.

I'm just running too short on time to tune it to where it needs to be.

I'm hoping a TM, tseries PCM, an exhaust, and the WI is going to be a quick way to livable

I'm not so concerned with "converting" either way.

I would also probably pull the pump if I go the TM way, just to eliminate the possibility of it locking up and smoking a belt halfway across the continent.

My tuning will just continue with a TM instead of the vac system.

Of course, I'll keep all the parts though....

My route goes right by Bill's place in ellensburg, I was half thinking of dropping in and seeing if he'd give a few " optimizing tweaks".

 

[Edzzed]

As for helping you beat a dead horse this is about the best I can do

It is easy enough to make your own T/M, I did it and then bought a Heath ecm, he gave me a free T/M so out went the old one. In my opinion heaths t/m was much better than the one I made. I would have to lift the hood and adjust mine if I was gonna tow, heaths I left alone. I can say for sure why the difference except it must have to do with spring compression. Ed

 

[buddy]

Increasing the boost and timing advance, lowers the EGTs, that why most people get lower EGTs with a PCM and TM. It also helps efficiency under load. Same can be had with the vacuum setup and a modded PCM.

8psi of boost is decent but a couple more pounds could make the difference in EGTs, especially if increasing fuel output in the PCM program and are under sustained load. I could sustain 8psi and up even on the stock PCM on a steep hill, before I increased fueling. So now I sustain more like 14psi, or more if my foot is to the floor. That probably more than most people would be comfortable with, which is why I would just recommend at least 10-12psi under sustained load with power PCM program.

 

[ak diesel driver]

even empty the boost would fall off on mine

 

[Odlaw]

As for helping you beat a dead horse this is about the best I can do

It is easy enough to make your own T/M, I did it and then bought a Heath ecm, he gave me a free T/M so out went the old one. In my opinion heaths t/m was much better than the one I made. I would have to lift the hood and adjust mine if I was gonna tow, heaths I left alone. I can say for sure why the difference except it must have to do with spring compression. Ed

x2 on what Ed said. When I replaced my GM-3 with a GM-8 it had a shiny, new Heath TM on it...so I left it and did not use my homemade one. The TM is made properly and the action is much smoother and is a set-it-and-forget-it design. Boost does not just fall off like mine did. It's set to 12 psi and it pretty much holds it right there...may drop back a 1/2 psi or so.

 

[NVW]

My home made TM worked really well right from the start, I must have got lucky on the spring choice.

I also saw a slight average increase in mpg. and a lot more turbo whistle with the higher boost.

 

[WarWagon]

Only change I made to my TM was when I replaced a weak lift pump. Had to turn the boost down as it went over 14 PSI. Altitude also limits what the TM and the turbo itself can do. I have run out of air and spiked EGT's several times just climbing the mountains here. The TM replaced the 6 PSI factory spring can on my 1993. The TM is done very well and does what is advertised no questions asked. My only complaint is in line with other members on here that there is too much boost unloaded and waste of MPG.

This is with the limited DB2 pump. With the DS4 you have lots more fuel at your disposal and quite frankly will run out of turbo.

With the budget in mind the A Team could pay for itself at the end of the trip in fuel savings. That and getting rid of the choke point where you loose power in higher engine RPM the stock turbo has.

 

[great white]

Pretty sure the ATT ran around 700 bucks last time I checked.

That's too much right now.

800 for exhaust, 500 for a PCM and 150 for a TM is gonna bleed me past dry.

Another 7-800 is out of the question. There's also a farts chance in a hurricane it's gonna save me 800 bucks in fuel.

God help me if the long block calves on the way.....

 

[Edzzed]

Pretty sure the ATT ran around 700 bucks last time I checked.

That's too much right now.

800 for exhaust, 500 for a PCM and 150 for a TM is gonna bleed me past dry.

Another 7-800 is out of the question. There's also a farts chance in a hurricane it's gonna save me 800 bucks in fuel.

God help me if the long block calves on the way.....

You can get an exhaust much cheaper than 800, iirc mine was 320. about 500 for ecm and with an ATT you don't need a t/m

 

[NVW]

BJ, would it be possible to have your SS exh sent to a member across the border and install it on your trip. It would save you a pile of cash if your wife didn't mind a delay.

 

[great white]

You can get an exhaust much cheaper than 800, iirc mine was 320.

Yup, you sure can. If you dont want stainless. I need stainless.

500 for ecm and with an ATT you don't need a t/m

true enough about the TM, that would essentially knock 150 off the total price.

Still, my gm8 is less than a year old and 150 is less than 700 all day long....

 

[JiFaire]

BJ, would it be possible to have your SS exh sent to a member across the border and install it on your trip. It would save you a pile of cash if your wife didn't mind a delay.

Leo, that's a great idea.

BJ, Garth can probably help you set that up, if you're interested. 800 bananas is a pile for an exhaust...

***on edit: there are two muffler shops in Ellensburg - you could make an appointment at one, get there real early and have the exhaust done, and be at Bill's place before noon for the rest...

Just thinkin' out loud (always a dangerous thing)

 

[great white]

Yeah, we've been around this tree before.

It's upwards of 200 bucks just to get on and off the island. About 100 bucks in fuel just to get to ferry and back on the island itself.

Add I another 50 -75 bucks in fuel to run around the mainland and that 450 dollar stainless system is now 800 bucks again.

Might as well just have it delivered to my door for the same price and save all the time and aggravation running around.

Having it done south of the border on the trip out is an idea, except that I've got to get it there pulling the big TT, which is the problem in the first place.

I'm not so sure I'll even be able to make it over the Malahat (http://www.vancouverisland.com/regions/towns/?townid=120) let alone get to Ellensburg without the described mods.

Pretty sure I'll be stuck with and 800 dollar exhaust bill ( that's with ups shipping), 500 for a PCM and 100-ish for a BH TM.

That's around 1400-1500 bucks.

I can manage that after the tax refund comes in.

I still appreciate the offer though Jim.

 

[Edzzed]

you can save some money off the duty and brokerage that UPS will charge if you were to have it shipped to http://www.hagensofblaine.com/index.php not to mention cheaper to ship it within the USA. You can then hop the ferry pick it up. have it installed stateside and then go to ellensburg for an ecm. Bill will also time your truck while there and make sure everything is good. just an idea

 

[Edzzed]

Another thought would be shipping it to the address I provided and I can pick it up and pay the duty on it. meet you at the ferry and you pay my out of pocket expenses. Where are you on the island.