Author Topic: Boost Pressure #'s (Read 8510 times)

camboscams · « **on:** February 04, 2009, 04:16:11 pm »

I've got a freshly rebuilt 1.6l na that i'm currently installing turbo componets and a TD.IP on (Thanks to cheifdiesel) and need to know what my limatations are as far as boost pressure is concerned. Both the head and block have been milled FLAT, new fiber 3notch heasgasket with Hylomar head gasket sealent, and new head bolts. With the IHI RH05 turbo i need to know how much boost the engine can take and not hurt the life of it, so i know were to set my wastegate.

If anyone has any ideas about this all info would be greatly welcomed.

8v-of-fury · « **Reply #1 on:** February 04, 2009, 04:41:53 pm »

i think i read somewhere that 15 would be pushing it on an n/a engine simply because it lacks the few certain components of t/d engines. I think if you run stock boost like what 10-12 psi or something like that you'll be good for power over a normal n/a and won't be really hurting the engine. However i think it might not actually be the pressure that hurts the engines its the heat that comes with the pressure, and thats what slowly kills the engine. Because if you really think about it, whats diff between a n/a and a t/d.. the td is better equipped to dicipate heat.. so my theory is its the heat that will harm your engine. owever it is just a theory

Hopefully a pro chimes in.. and tells me if im right or not? lol

camboscams · « **Reply #2 on:** February 04, 2009, 05:48:37 pm »

Thanks 8v, anyone done this conversion, or firsthand accounts?

jtanguay · « **Reply #3 on:** February 04, 2009, 05:54:23 pm »

run as much boost as the engine will produce. you'll probably just blow a HG unless you run the 1.9 MLS. now if you turn up the fuel and boost, you could potentially dig the motor an early grave. mild performance increase should be ok.

i think it was MJF who was running about 180+hp out of motor with an N/A mech head, so i wouldn't worry too much about that, but i'm pretty sure his block had the oil squirters... those are necessary when running high EGT's otherwise you'll melt the pistons.

as with any diesel, black smoke is bad. tune the engine to run with no black smoke, and everything should be just fine. install an EGT gauge if you really want to push it.

8v-of-fury · « **Reply #4 on:** February 04, 2009, 05:57:28 pm »

ahah! so it is the heat that wrecks these engines and not the boost. If you are to use a metal Hg and studs, as long as you tune it to run clean of black smoke you should be able to hit some crazy boost levels while maintaining the longevity of the engine. Like Jt said, its the turning up of the fuel that will produce the smoke which will melt things. lol keep the fueiling right and the boost high, and you;ll be a happy camper!

good luck with what your doing!

jtanguay · « **Reply #5 on:** February 04, 2009, 06:01:23 pm »

Quote from: "8v-of-fury"

ahah! so it is the heat that wrecks these engines and not the boost. If you are to use a metal Hg and studs, as long as you tune it to run clean of black smoke you should be able to hit some crazy boost levels while maintaining the longevity of the engine. Like Jt said, its the turning up of the fuel that will produce the smoke which will melt things. lol keep the fueiling right and the boost high, and you;ll be a happy camper! good luck with what your doing!

boost is relative to the fuel though... you'll find that underfueled, it is much more difficult to achieve the high boost levels. i don't really like that trade-off, but there is a solution! VNT :lol:

8v-of-fury · « **Reply #6 on:** February 04, 2009, 06:05:13 pm »

But if you properly fuel, like slightly under fueled so that you are not producing any smoke, and make sure you dont go over 1400 degrees you should be ok on an n/a and still be able to reach crazy numbers for an n/a engine. How does a VNT differ? what is it about it that makes them so much more likeable for n/a turbo mods? do they work differently then a normal turbo? Im sure the OP would like to hear about this as well, so this is not a thread jack

camboscams · « **Reply #7 on:** February 04, 2009, 06:11:49 pm »

Well if i had a choice i'd perfer not to melt my new "King" pistons. so basicly what i gather from these statements is to keep enough boost to keep the smoke levels down. But not enough to blow the HG.(If only i knew what the magic number is? :lol: )

Quote

but there is a solution! VNT

BTW the IHI is ballbearing 30% faster spooling then thrust bearing :twisted:

8v-of-fury · « **Reply #8 on:** February 04, 2009, 06:19:24 pm »

sadly i think depending on your setup. it will be trial and error mostly. Start low and go from there.

oh and dont forget to have some mad fun. lol

camboscams · « **Reply #9 on:** February 04, 2009, 07:39:33 pm »

Thats right Cheese Man! I plan on having fun regardless of my Boost Pressure!!!

saurkraut · « **Reply #10 on:** February 05, 2009, 08:53:48 am »

You can run 25+ PSI with out going over 1100° F egt. I've done it with my 1.5TD experiment. I ran a K24 with the waste gate disconnected, disabled blow off valve, 2.5" exhauste turbo to rear bumber, and I set the full boost EGT with the LDA pin. The free block i used was cracked, so I didn't get any long term running out of it. But it ran good, and had surprizing high RPM power.

The only issue I had was lower RPM egt. If I lugged it at all, the egt would climb rapidly. If I watched my gear selection, the EGT stayed very low.

An EGT probe is a must with a turbo on a NA motor. I was running the Spruce thermocouple and a VDO Vision gauge.

jtanguay · « **Reply #11 on:** February 05, 2009, 10:06:42 am »

this diagram i just made should hopefully give you an idea of why a VNT is more efficient, and faster spooling than the traditional style turbo. a ball bearing turbo will definitely be better, but a ball bearing VNT would be the real deal

and the image below is the VNT turbo vane actuation. when the vanes are open, the exhaust gases are directed to the turbine. when they are closed, the exhaust gases bypass the turbine, yet the turbo can still spool at this point, showing just how efficient this system is! (because the vanes do not create a seal like a wastegate) they call some VNT systems infinitely variable, although infinitely is hard to swallow, as i'm sure there is a calculation of just how many variations there can be :lol:

to give you an idea of what kind of lag these turbo's have, Tintin has some video's floating around (google video i think) where he was blipping the throttle and achieving boost spikes of 30 psi NO LOAD!!! try that with your conventional style turbo, or even ball bearing turbo??? :wink:

and saurkraut is correct about the low EGTs while running high boost, but every little bit of flow increase helps. porting, polishing, bigger exhaust, fresh air filter, etc. will all help keep the gases moving which will in turn keep the EGT's down.

8v-of-fury · « **Reply #12 on:** February 05, 2009, 02:54:31 pm »

Very nice picture Jt

So what your saying is that with a turbo on an N/a you can run as much boost as you can generate, but in the same breath keeping your egt's low enough and not lugging it and selecting the right gear you will not harm the life of the n/a engine? that's pretty sweet! I like the sounds of this, free flowing exhaust and intake from a gasser, port matched, and egt guage. All while keeping the egt's low you can run like 25+ psi. thats insane! i love it.

So in theory boost is not the killer of a diesel engine, but the heat involved with the boost is. very noice!

camboscams · « **Reply #13 on:** February 05, 2009, 06:35:53 pm »

I always thought it was the compression strokes combustion pressure with the added boost that blew the head gaskets. But from Jt's statement it is the EGT's that do it.

Interesting....

Smokey Eddy · « **Reply #14 on:** February 05, 2009, 06:54:34 pm »

building on what jt said about boost lowering EGT

I disconnected my turbo to see what it was like with 0 boost and my egt went up to 800 with just a downpipe on it. with the turbo connected up i never saw my gauge register and it starts at 600