is this a crazy idea?

[razorback]

ok, i know most of the turbos on our idis are about 8psi with a max of 10.. but my turbo is considerably bigger than a banks, its around the s400 size andi am afraid of getting too much boost. ( i can already hear turbine whine around 1500rpm in P and N) so i want to protect myself and set it so it cant go over 14 or 15 psi.. i know normally a wastegate is done to do this..but while at work i was looking at some of our well accessories (im a plumbing dept manager at lowes) and saw we carry one for 75 psi.. that got me thinking.. so i searched and found one that was 15psi preset 35ish bucks).. now would this work for what i want to do, in theory it should do the same thing correct? or do i really just need to get a wastegate?


if i have to get a wastegate, where would i install it? (intake, exhaust, etc etc)


and yes i know putting a turbo the size of a s400 is crazy in itself..

 

[sassyrel]

theres lot of em on ebay----just type in blowoff valve. and make sure its large enough!!!

 

[razorback]

do i need a blow off valve or a wastegate?

 

[91f2504x4]

You need a wastegate, a blow off valve (in the sense of turbochargers) vents the inlet charge air to allow the turbo to continue to spin between shifts, instead of barking and slowing down. A wastegate which is what you want, vents excess exhaust gas past the turbine wheel, so that you do not overboost the engine or go past the efficiency range of the turbo.

I think that you are thinking of a pop off valve, similar to what is on a hot water heater, don't use this, it will not be very efficient at dumping a large volume of charge air, you need to just get a external wastegate if you are concerned with overboosting your engine.

To install an external wastegate, you are going to have to put a hole in your exhaust pre-turbo and then weld a flange here to mount the wastegate. Then you are going to run a boost reference line to the wastegate from your intake, in the same place that you would hook up a boost gauge. Then you can reroute the exhaust from wastegate to the exhaust pipe behind the turbo or just dump it under the truck.

 

[razorback]

im looking on ebay now for wastegates. arent too badly priced. 90ish bucks for a 60mm 4-8 psi

 

[91f2504x4]

im looking on ebay now for wastegates. arent too badly priced. 90ish bucks for a 60mm 4-8 psi

You can change out the spring for 12psi, which is probably what you would want, I think you can get a 15 psi spring too, but you always expect to get a couple more psi than what the spring is for, in most cases that I have dealt with anyway. Most of the wastegate can be fine tuned, or you can get an electronic boost controller and use that to regulate your boost, but I don't really think you need that in this application.

 

[razorback]

what size do you think i need? 38, 44, 50, 60..etc. mm?

 

[91f2504x4]

what size do you think i need? 38, 44, 50, 60..etc. mm?

Go with the biggest one you can afford, don't pay a buttload if you don't need to. The bigger the gate the easier it will be for the exhaust gasses to get out, especially if you are using a turbo that could possibly make a lot of boost but you dont really want it to.

 

[Diesel JD]

Have you even tested this thing out on the road? One sure way to not overboost is to watch the boost gauge and back your foot out of it if it gets to be too much. I bet it doesn't make nearly the boost you think it will. I really wouldn't let it get over 12 psi with stock 6.9 head bolts.

 

[razorback]

took it for a road test today.. started off it would only get about 3psi. but when you would stop and start go go again, then slowly get on it, you could hear it build boost.. then a sudden jump in boost.. highest i saw it was 10psi.. that was somewhat babying it..im a little worried what it would get to when its towing or under steady load. it sounded really nice going through almost straight 4 inch tubing. there are still a few issues im not real comfortable with (way its acting, etc) i dont think it would be 100% reliable and since ill be moving back to fayetteville to finish school, i need something reliable. so im going to take the turbo off and just keep it NA. if i had more time i would keep throwing money at it, but for now im going with reliable/less pain in ass over something that sounds like a big block ford with a turbo whine..

 

[Diesel JD]

I think I'd just run it and drive by the gauges. I don't think you're likely to do any damage with things the way they are but hey its your call. You aren't going to be doing a lot of heavy hauling or towing are you?

 

[91f2504x4]

took it for a road test today.. started off it would only get about 3psi. but when you would stop and start go go again, then slowly get on it, you could hear it build boost.. then a sudden jump in boost.. highest i saw it was 10psi.. that was somewhat babying it..im a little worried what it would get to when its towing or under steady load. it sounded really nice going through almost straight 4 inch tubing. there are still a few issues im not real comfortable with (way its acting, etc) i dont think it would be 100% reliable and since ill be moving back to fayetteville to finish school, i need something reliable. so im going to take the turbo off and just keep it NA. if i had more time i would keep throwing money at it, but for now im going with reliable/less pain in ass over something that sounds like a big block ford with a turbo whine..

What exactly are you worried about reliability wise? My turbo will make 18+ psi but I just don't keep it to the floor all the time. In normal driving conditions I typically see 10-15psi at the most, if I hammer on it, up a big hill it will go above 15psi, but I just let out of it, and I can climb the hills pretty fast. I may eventually put an external wastegate on mine but I don't mind it the way it is. I would have to be running wide open with a hard load before I would be concerned with overboosting. If you are only seeing 10 psi max I don't think you have much to worry about. As soon as I hook it back to my gooseneck with my pulling tractor on there, I will see if I need a wastegate or not, I think total weight of tractor and trailer combined it roughly 15k.

 

[razorback]

ok the 2 issues/concerns i had were this

first one, sometimes it sounds like its sputtering.. not enough fuel or something. this is idling, not under throttle.. also there is also very very little smoke

and second one, when i turn it off and take the key out, it takes a second to shut down. after the road test it seemed like it took 5-10 seconds..

both of these were not present while the banks was on there.. the shut off im wondering if its the shutoff solenoid? how would i test that?

first problem.. not enough fuel?

 

[91f2504x4]

ok the 2 issues/concerns i had were this

first one, sometimes it sounds like its sputtering.. not enough fuel or something. this is idling, not under throttle.. also there is also very very little smoke

and second one, when i turn it off and take the key out, it takes a second to shut down. after the road test it seemed like it took 5-10 seconds..

both of these were not present while the banks was on there.. the shut off im wondering if its the shutoff solenoid? how would i test that?

first problem.. not enough fuel?

If it is idling rough and smoking, you either have a slight timing issue or you may need new injectors and a good timing to go with them.

The second issue you described does sound like a FSS sticking. You could try running some treatment of your choice through the fuel system.

 

[6 Nebraska IDIs]

Both issues could be a failing IP, in my opinion. But nevertheless both are fuel injection related and have nothing to do with your turbo, they'll take a crap no matter what you're running for aspiration. I'd have the injectors pop tested, if they are supposedly low mile, and find the culprits, if there are any. Second, flush your injection system with some ATF or BG fuel system cleaner, either one should get that FSS unstuck.

Its your truck, but IMO you're just making more work for yourself by pulling the turbo system.