96 Auto Stock Boost Psi.???

[KRoaden]

I think Santa's brining me some gauges for Christmas and I'd like to get a head-start on baseline values!! Boost how many psi and do you guys see a vaccum at idle (my gauges has vaccum as well)?? EGT Temp how high??? Thanks alot guys and have a great Holiday Season!!!!!!HOHO

 

[Joe G.]

You should never see any vacuum on a diesel. The intake system is presureized by the turbo charger. The vacuum pump is a separate deal to provide for brakes, cruise control, and 4X4 front axle engagement. EGT in pre turbo should be at or below 1300. After at or below 1000. With a stock '96 auto the maximum boost you should see is about 18 PSI. That's where the waste gate opens.

 

[ProvenPerformance]

KRoaden-



See my signature for truck details...



At idle, no boost.

At 60mph, no load, 4-6psi (depending on wind / conditions).

At WOT, I peg my AutoMeter guage at 35psi.



At idle, 250-300 degF.

At 60mph, no load, 500 degF typically, up to 600.

At WOT, I don't recall ever seeing over 1100 degF... but I've never been at WOT for longer than maybe 5-10 seconds.



I wouldn't get a guage with vacuum if I were you... . waste of valuable guage display space!



Tom

 

[Dieselnerd]

When my truck was stock the boost topped out at 18. 5 pounds. The vacuum gauge isn't needed. You get vacuum from your vacuum pump but it should remain pretty constant unless you have a big leak, it doesn't have any meaning as far as your engine performance. EGT depends on pre or post turbo. Post turbo stock runs about 800 to 850 max as I recall.

 

[SlyBones]

Call me stupid, but I think the vacuum he is referring to is not the vacuum from the vacuum pump. In gassers when the throttle body is closed, your at idle, the piston is sucking against the closed system, and its has vacuum. As the throttle body opens the vacuum decreases until WOT where vacuum is 0. Or something like this. Seems like back in high school when we had a turbo rabbit we had went from -18psi to about 8psi. Above 8psi it pinged like crazy. I bet all non turbo or supercharged gassers from from vacuum to 0 as the throttle is pressed and RPM's rise.



Anyways these diesel dont have butterfly's or throttle bodies. So therefore there is no vacuum, correct??????

 

[KRoaden]

SLybones pegged it right on the head. I'm thinking of gassers. It seems to me that you have to have some vac. around idle, due to no boost and the pistons still drwing air... ??? . Not sure on this topic. the boost gauge she/Santa's getting me has 25Psi boost to 35 inches of mercury. If she got it I'll proably hook it up and see what happens, after all I can buy another gauge if start to gain too much boost!!

 

[Reddog1]

Vacuum - Pressure

I had a boost/vacuum gauge on the shelf from my gasser turbo days. This was the first gauge I put on my Ram, and I have been looking at it for several months, flatland, up hill and down.



My Ram is stock, and if it ran any better, I might pee on myself .



There an’t no vacuum at anytime on MY Ram, other than that from my vacuum pump.



SlyBones - no vacuum is correct!



ProvenPerformance – Which mod brought your boost up to 35 PSI?



Dieselnerd – What mod increased your boost from 18. 5 PSI?



My Boost at cruse typically between 4 & 8 lbs with maximum boost at 18 lbs.



My gauge is Stewart and Warner. If I replace it, it would only be for aesthetics (?).



Kroaden – Walk softly, you hurt Santa’s feelings, you go on the bad list, and we all know what happens then.







Wayne

 

[Dieselnerd]

Red, my boost was increased by installing a TST 230/605 plate (which dyno'd at 240HP with TC locked up). Boost is now set at approx. 28 pounds although with the adjustable elbow I can get it over 36. I settled on 28 after testing for minimum smoke and minimum egt under full throttle. 28 pounds is more than enough to burn all the fuel, more air just means higher egt (air gets hotter as it's compressed) and takes more power to make the higher pressure. Was good thread on this subject several months ago.

 

[ProvenPerformance]

Reddog1-



The installation of the Bosch plate brought my boost up to 35psi. I should add though, my truck stock, produced 25 pounds of boost. I am not using a "boost elbow" and I just replaced my original Autometer with another (they now have the new antifog lenses on their guages so I sent all of mine back and got new ones), so I know that the guage is accurate... as they both read identical.



Hope this helps.



Tom

 

[Reddog1]

Your experience suggest the TST 230/605 plate will raise the boost to approximately 35 lbs. Is this true?



I have seen two boost elbows: One has a 1/64 (I think) bleeder hole (external) and a metered orifice with an adjustment screw, and the other has no bleeder hole and no metered orifice (standard elbow) with an adjustment screw only. Know why?



I would think, the adjustment screw only determines the rate of the boost. If you wait long enough, the pressure would be the same on each side of the adjustment screw. Conversely, the bleeder would limit the amount of boost the gate would see. Do I understand this correctly?



Wayne

 

[ProvenPerformance]

Wayne-



I'm the wrong guy to be asking. Through the TDR, because I already have such high boost, I was told not to even bother with the elbow... so I'm not familiar with them.



One thing I should make clear, though, is that I'm not running the TST plate. The plate I bought (from a Cummins dealer) is also rated at 230hp/605lbft... but cost 1/2 the price.



Tom

 

[Reddog1]

Tom



Could you elaborate more on your plate?





Wayne

 

[ProvenPerformance]

I actually bought the plate from a guy that works at Cummins.



After words, I talked to our local dealer, and according to him, the plate is found in several different 5. 9 equipped vehicles. He said it's a stock plate in a lot of delivery type trucks equipped with 5. 9's.



The slip in the package has the following numbers on it:

2 427 133 620

870 015110



Hope this helps.



Tom

 

[HoleshotHolset]

This could prove to be a cheaper alternative to the $300 plates currently offered.



However... . most Cummins dealers require a CPL... . and the CPL you give them off your B5. 9 in your Ram won't coincide with the CPL of the plate that you want.



Moral of the story: Call Piers... if he doesn't have something for your 12-valve at an affordable price, then you don't need it!



Matt

 

[Joseph Donnelly]

I haven't looked at that plate but I have inspected the 300 hp plate and compared it to the TST plates. The TST's are a lot richer, compensating for our smaller injectors and pump parts as needed. When TST was developing their plates, Bosch and Cummins told him (during meetings at the Cummins plant where he worked before retiring) that it was impossible to duplicate the 230 hp engine package with just a torque plate. Mark Chapple proved them wrong. This should indicate to you just how much richer his plates are than anything Bosch/Cummins has tried.

 

[KB0OU]

STOCK PSI??

How can anyone here give you stock psi etc. everyone has bombed it by now!!!

 

[Driftwood Ram]

Re: STOCK PSI??

Originally posted by KB0OU

How can anyone here give you stock psi etc. everyone has bombed it by now!!!

18 lbs is the correct answer for those that can not remember. hehe

 

[Reddog1]

Tom – Thanks for the info.



Joseph Donnelly – Interesting info, thanks. Is it true the TST 230/605 plate will raise the boost to approximately 35 lbs. ?



Joseph Donnelly – Could you explain boost elbows. As I stated on an earlier post, I have seen two boost elbows: One has a 1/64 (I think) bleeder hole (external) and a metered orifice with an adjustment screw, and the other has no bleeder hole and no metered orifice (standard elbow) with an adjustment screw only.



I would think, the adjustment screw only determines the rate of the boost. If you wait long enough, the pressure would be the same on each side of the adjustment screw. Conversely, the bleeder would limit the amount of boost the gate would see. Do I understand this correctly?



Maybe we should start another thread on the boost elbows?





Wayne