TST #4 vs. #5

[cumminsgetme]

I currently have a #5, thinking about switching to a #4. Did a search on the coparison of the two but came up short. Has anyone dyno'd the two plates? Mark with TST said that he hasn't dyno'd the #4 but guesses it to be around 330hp. More importantly... . how do they compare in seat of the pants feel? 370's are coming soon... wonder how a #4 would compliment that.

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94' 2wd,5spd,#5TST,15%pump mod,K&N,imellmoke

 

[John_P]

cumminsgetme:

I have the #5 TST plate right now with
alot of pump mods and the 370 Diamond B
Injectors from Piers. My truck dynoed
at 381 H. P. /1069 Torque at the "Scheid
Diesel Rally" last September. You can
look at my "signature" to see what
mods were done to the pump.

Anyway, this should give you a base-
line for your truck.

--------
John_P

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Red '96 4x4 2500 Auto 3. 54, TST #5, Major Pump Mods(By "Scheid Diesel") 370 Diamond B Injectors, Gov. Spring kit, AFC Spring kit, Banks Exhaust, Prime Loc, Cummins Chrome Kit,Psychotty Air Filter, Pro-Torque Converter, BD Valve Body, BD Pressure Loc, Isspro Gauges, Sendel 16" Alum Wheels w/ 33" BFGs

 

[Sled Puller]

I just had my #5 taken out,and the stock one put back in.
I had the pump on the stand, and they adjusted it to run just as good or better than the #5. I'll let you know more after I hit some familiar hills.
I am starting to get suspicious of $300 plates.
Gene

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1997 Cummins Dodge 4x4 "One Piece At A Time" Bombed & Amsoiled. Amsoil Premiere Direct Jobber, Member of: NRA Business Alliance, GLTDR, WANTED: Wrecked Dodges.
www.awdist.com

 

[Joseph Donnelly]

No reason to get suspicious. Understand that the pump works like this: as the "rack" moves forward, more fuel is made available to the injectors (i. e. the pressurized fuel is available for more degrees of crank rotation). There are adjustments inside the governor that can give the rack more forward movement vs. rocker position. The torque plate allows the rocker to move forward more and hence the rack to move too. However, the torque plate still determines the shape of the torque curve. Moving the plate or its curve forward is the same basic thing as adjusting the rocker vs. rack position to give the rack more forward movement. Hence the pump shop can give you the torque curve that is on the plate only, but they can move it forward. In that way they can increase fueling the same amount throughout rpm. Well designed torque plates increase fueling different amounts vs. rpm and thus change the torque curve.

"A little knowledge is a dangerous thing" #ad

 

[cumminsgetme]

Joe,
I've been thinking about adjusting the rack travel (if I remember correctly it's on the back side of the pump under two screws that are safety wired??. . correct me if I'm wrong). It seems like I've heard people say not to... . and others say go for it. I have a burning desire to know all that there is about these pumps. How do you feel about making these adjustments. In my quest to learn more about these pumps, I feel that the only way gain knowledge (and if a particualar procedure really works) is to dive in and see what happens. How would a rack travel adjustment compliment an already forward positioned plate and afc?
Thanks
Cord

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94' 2wd,5spd,#5TST,15%pump mod,K&N,imellmoke

 

[Cooker]

Gene,

Why did you remove the #5.

Can you comment more on how the truck runs now as compared to with the #5. How is the fuel economy now?

Thanks,
Ryan

 

[Sled Puller]

Ryan,
I took it out to see what it is like with a properly tuned pump compared to the back yard mechanic fix. It is easy to put back in if I want.
Have not had it enough time to tell. I maybe selling it later.

Joe,
I consider the pump tech to be more than a little knowledgeable -15 years of building Hi-Po pumps is a hair more than you hobbyists! #ad

Notice I have not thrown my plate in the trash, but my eyes are always open.
I think a few dyno runs at "Thunder in Muncie" are in order!

 

[Joseph Donnelly]

I was not implying that the pump man was not knowledgeable. On the other hand, I know of professionals who have 15, 20 even 30 years of "experience" but "limited ability. " This hobbyist has documented his Sickly Ram at 609 hp. I never asked Scott at my Bosch shop how many years of experience he has. I only care that his work is the best. How much hp has your professional pump man gotten?

#ad
Bosch teaches their techs "do vat you are told, hmmm, vy vould you vant to do dat?" Give me a few more years of "experience" and who knows what will happen #ad


If you shear that $1 stop pin from too much rack travel you will understand why adjusting from the back can be bad. If your are lucky only the governor will grenade. I make sure my torque plate (it's in the stock position by the way) does not allow too much rack travel. #ad


[This message has been edited by Joseph Donnelly (edited 05-06-2001). ]

 

[dieselburner]

Originally posted by cumminsgetme:
I currently have a #5, thinking about switching to a #4. Did a search on the coparison of the two but came up short. Has anyone dyno'd the two plates? Mark with TST said that he hasn't dyno'd the #4 but guesses it to be around 330hp. More importantly... . how do they compare in seat of the pants feel? 370's are coming soon... wonder how a #4 would compliment that.

I've had both in my ride. I keep the #4 plate in because it gives more torque than the #5. The horse power is the same. I have not ever put my truck on a dyno. These are all "seat of the pants" from taking the truck out and running it.
Steve

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1998 2500 Quad Cab, 12V, 5spd, 4x4, HD Transfer Case, 370HP Diamond B Injectors, #4 TST, 16cm2 Housing, AFC Spring Kit, BD Governor Spring Kit and other governor modifications, Walker Muffler, 285/75-16 BFG AT's, Stainless Steel Tube Steps, Reese Fifth Wheel Hitch, Leather, CD, LSD Dana 80 Rear, 60 Front, McLeod Dual Disc Clutch, Rancho RS9000 Shocks, Rancho Steering Stabilizer, ATS Exhaust Manifold, Psychotty Air Induction, BD Exhaust Brake, Enterprise Engine Delivery Valves

 

[Smoker]

What are the numbers that are stamped on the plates? I have a TST plate that Mark said was a 4. 8 plate and that's whats stamped on it too? Is this #4 bigger than my #4. 8? Anyone heard of 4. 8 plate?

 

[Joseph Donnelly]

4 = 4. 8 = 48. Bad math but works for plates #ad

 

[DHRA]

Joe, don't be so quick tongued to Gene's attempts to rile the Sickly driver! The pump guy he speaks of has forgotten more hp than you will ever see. You are right about the do vat you are told though!

 

[cumminsgetme]

What are the most common modifications a pump shop makes. My pump has been turned up "15%", but at the time I was new to diesel performance... . and basically didn't know whether my *** was up or down! I either didn't ask the right questions or they didn't want to offer any info. I understand that they put them on a stand and test flow rates... . but what kind of adjustments are they making. Are they simply making the same adjustments that we're making in our drive ways... however, using the aid of a stand to measure flow rates in an attempt to get her dialed in just right.