Looking for advise on a turbo setup boost/EGT issues

[hackster]

Working on my crew cab tow/adventure/end of thw world rig.


Put a crew cab cab on a 93 chassis rebuilt the Getrag and put a Valair Clutch setup in there.



Mods:



75 or 100 hp POD's

Denny T fuel pin

low pressure piston lift pump/ new filter and fuel heater delete

factory intercooler

4" turbo back exhaust

4" intake tube and open element air filter

Source Boost Boots





So I had a he341 on it, reclocked with the wastegate welded shut as I was trying not to build more stuff.... The problem there was that I was boosting too much, could peg 40 lbs and do it easy. Towed good and EGT's were reasonable but did not tow much with it that way aftraid to pop the head gasket



So I pulled that setup off there and got another 341 since it was cheap. I put that on there, reclocked it both sides and built a new discharge pipe to the intercooler.



I hooked up all my stuff Truck and Trailer and Buggy up to the rig and headed for an initial tow before I head to Moab next week. Turbo seems laggy compared to the one that is welded up. Egt's were quite a bit higher and boost is low. Before boost was up in the high 30's to max of about 40. Egt towing up sylvan in 4th was right about 1100/1150 or so.



Towing up to browns camp last night up highway 6 on the freeway 4th gear, I had to back out of it to get EGT down to 1200 and only running 23-25 lbs of boost.



Seems slower to make boost too.



Wastegate actuator is tight on the wastegate arm, i have to pull it a fair bit to get it on there.



I did build an adjustable boost elbow, but I have cranked the set screw down and dont seem to be building any more boost. I am going to try to tighten it down some more tonight and retry it.



So, In my opinion, I need more air in the combustion chamber to lower my EGT ie I have too much fuel. Is this the right assumption to make?



Also, if I need to upgrade the turbo, I am not opposed to it, just need to know a direction to look, so much info out there about turbos and opinions.



Thanks in advance,



Sean

[dunes450r]

the very small (9cm2) exhaust housing on the 351 is a known choke point. you hear of people complaining that a 12cm hx housing is small and can cause high egts, a 9 is even tighter. i know lots of people on here swear by them on here, but I still think the housing is just a little too small, especially when combined with bigger sticks and towing. they flow lots of air, but they have high drive pressure to do it.

RC said he had 30psi of boost to maintain 50mph towing 10k with a 351
I towed 8.3k at 60mph with an H1c and 12cm exhaust housing and only had 7-8psi

lots of fuel, and lots of weight is just a little too much for the small exhaust housing IMO. i'm sure people will disagree and say i'm wrong but oh well, my opinion

i think you need to look into a bigger turbo if you want to tow with full power. something like an hx40 would probly work and be cheap, or start looking into an s300g or similar

[BILTIT]

So you replaced a welded WG 341 with an operational WG 341? sounds like its a wastegate issue.

[BILTIT]

the very small (9cm2) exhaust housing on the 351 is a known choke point. you hear of people complaining that a 12cm hx housing is small and can cause high egts, a 9 is even tighter. i know lots of people on here swear by them on here, but I still think the housing is just a little too small, especially when combined with bigger sticks and towing. they flow lots of air, but they have high drive pressure to do it.

RC said he had 30psi of boost to maintain 50mph towing 10k with a 351
I towed 8.3k at 60mph with an H1c and 12cm exhaust housing and only had 7-8psi

lots of fuel, and lots of weight is just a little too much for the small exhaust housing IMO. i'm sure people will disagree and say i'm wrong but oh well, my opinion

i think you need to look into a bigger turbo if you want to tow with full power. something like an hx40 would probly work and be cheap, or start looking into an s300g or similar

The above bolded is not true.

I have towed 10k camper at 60-70mph with only 8psi, no problem. The 351 EH is not as restrictive as you think (at our power levels anyways).

Mind you i am running stock injectors but it comes down to pump tuning which controls egt's the most. I dont like smoke so i dont waste fuel by pouring it out whenever i hit the throttle. I can pull that same camper setup up a steep grade at 1230egts wot, 40psi and accelerate the whole way and be 75+mph at the top.

[BILTIT]

So i would recommend either changing to a 351cw (60mm)or larger or make the jump to compounds. The alternative is turn your fuel down.

[BILTIT]

You have to keep in mind the 9cm is UNDIVIDED VS a DIVIDED 12cm, so they are virtually the same size housings. The 9/12cm works wonders with a std trans, the autos seem to like a 14/16 better.

[RCCUMMINS89]

Might be a good candidate for a 60/68

The he351cw is a great towing turbo, but yes it can be overwhelmed and over boosted due to the small exhaust wheel (not the housing, but the wheel).

There is a reason that an S300G 57/65/12 or 14 is a good towing turbo, when the compressor and exduser get close together they can become overboosted when towing heavy. This is why I'm not a fan of a 62/65 and a 62/71 is just huge. The best ooption for a used take off turbo is the he351cw, which will cool a lot better than the 341 and you have to have a working wasetgate with these turbos.

[hackster]

the very small (9cm2) exhaust housing on the 351 is a known choke point. you hear of people complaining that a 12cm hx housing is small and can cause high egts, a 9 is even tighter. i know lots of people on here swear by them on here, but I still think the housing is just a little too small, especially when combined with bigger sticks and towing. they flow lots of air, but they have high drive pressure to do it.

RC said he had 30psi of boost to maintain 50mph towing 10k with a 351
I towed 8.3k at 60mph with an H1c and 12cm exhaust housing and only had 7-8psi

lots of fuel, and lots of weight is just a little too much for the small exhaust housing IMO. i'm sure people will disagree and say i'm wrong but oh well, my opinion

i think you need to look into a bigger turbo if you want to tow with full power. something like an hx40 would probly work and be cheap, or start looking into an s300g or similar

The above bolded is not true.

I have towed 10k camper at 60-70mph with only 8psi, no problem. The 351 EH is not as restrictive as you think (at our power levels anyways).

Mind you i am running stock injectors but it comes down to pump tuning which controls egt's the most. I dont like smoke so i dont waste fuel by pouring it out whenever i hit the throttle. I can pull that same camper setup up a steep grade at 1230egts wot, 40psi and accelerate the whole way and be 75+mph at the top.

Do you have studs and a head gasket? I think I have two problems here, either I have a leaking wastegate or I have a turbo that is less spin happy than my previous one.

When I was putting it on, i did notice that it did not spin quite as free as the 341 that I was just removing.

Tonight I am going to wire the gate closed tight and see what happens, if all is well then I know the actuator needs adjustment, if it sucks balls still I either have a turbo that is unhappy or a wastegate that is not sealing up.

And yes I removed a welded 341 and replaced it with an unwelded 341. It was a beast before the welded/ unwelded swap but I was afraid of popping a head gasket.

Getting ready to haul my setup down to moab in a week and a half and I really need to have this worked out by then.

Thanks a ton for the thoughts and please keep them coming.

Sean

[RCCUMMINS89]

the very small (9cm2) exhaust housing on the 351 is a known choke point. you hear of people complaining that a 12cm hx housing is small and can cause high egts, a 9 is even tighter. i know lots of people on here swear by them on here, but I still think the housing is just a little too small, especially when combined with bigger sticks and towing. they flow lots of air, but they have high drive pressure to do it.

RC said he had 30psi of boost to maintain 50mph towing 10k with a 351
I towed 8.3k at 60mph with an H1c and 12cm exhaust housing and only had 7-8psi

lots of fuel, and lots of weight is just a little too much for the small exhaust housing IMO. i'm sure people will disagree and say i'm wrong but oh well, my opinion

i think you need to look into a bigger turbo if you want to tow with full power. something like an hx40 would probly work and be cheap, or start looking into an s300g or similar

The above bolded is not true.

I have towed 10k camper at 60-70mph with only 8psi, no problem. The 351 EH is not as restrictive as you think (at our power levels anyways).

Mind you i am running stock injectors but it comes down to pump tuning which controls egt's the most. I dont like smoke so i dont waste fuel by pouring it out whenever i hit the throttle. I can pull that same camper setup up a steep grade at 1230egts wot, 40psi and accelerate the whole way and be 75+mph at the top.

For the record, I did say that in a post.

However, I have since hauled the same thing and don't know what i was smoking that day The 30 psi I was remembering was up a pass. Sometimes we all forget and say stupid things.

[dazedandconfused]

Have you checked for boost leaks since the swap?

[BILTIT]

I do have a headgasket, lol (stock i assume) but no studs. I have a set of new bolts ready to be installed though. I will do studs when i blow a gasket and need to pull the head. I will most likely get the head ported and install a cam at the same time.

I dont run much timing which is what saves me right now i think, I only have the m&h spacer.

[dunes450r]

You have to keep in mind the 9cm is UNDIVIDED VS a DIVIDED 12cm, so they are virtually the same size housings. The 9/12cm works wonders with a std trans, the autos seem to like a 14/16 better.

so you either have 6 cylinders of flow going through 9 cm, or 3 cylinders of flow going through 6cm, either way its a substantial increase, even though its only a small incremental increase

[RCCUMMINS89]

An he351cw has a non divided 9cm housing.... non divided housings out flow a divided housing of comparable size. A 9cm housing on the 351cw flows in comparison about the same as a divided 12.

[RCCUMMINS89]

Another thing is..... people get caught up too much on the housing size. Yes a larger housing will flow more, but when it all comes down to it..... it has to leave the exhaust wheel. The exhaust wheel size has just as much play in it. As does the way the wheels are configured, etc......

[dunes450r]

An he351cw has a non divided 9cm housing.... non divided housings out flow a divided housing of comparable size. A 9cm housing on the 351cw flows in comparison about the same as a divided 12.

how? you have X amount of exhaust to flow through X amount of space (let's just assume the exhaust wheel is the same size) a divided housing splits the exhaust flow into the front 3 cylinders and the back 3 cylinders correct? and an undivided housing housing flows all 6 cylinders through the total volume.

either i'm missing something, or it really is that simple. care to elaborate?


also thanks for clarifying on your towing boost, i thought that was outrageous when you said it, but who am i to tell you what your stuff does.