Bosch starwheel question

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Could someone, in laymans terms please, tell me what adjusting the starwheell actually does to the truck?? What happens if I hypothetically take it to the extreme in the all the way out and all the way in position?? And lastly if I turn it will I
A. notice more hp(empty)
B. get better fuel mileage
C. notice ANY change(unless I am
towing something)
Just trying to get a better understanding of how the pump works
P. S. If I was to lose that cap during driving would fuel come out that hole??(just wondering) THANKS

 

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Inside the pump at the back is a rubber diaphram that is pushed against by turbo boost pressure and that partially determines how much fuel is injected at what boost and engine speed. As I understand it this is primarily to reduce low rpm smoke and help fuel economy. When you turn the star wheel it either increases or decreases the spring resistance to the boost pressure and will let more fuel flow at lower rpm and boost when turned the correct direction. No there is not any fuel under that plug (at least I havnt seen any). Its a simple adjustment that takes 2 minutes so play away and dial in as much power as is there and balance that against how much smoke you will tolerate and enjoy the increase in low end power. I believe this is correct info but am willing to learn if it isnt.
This info only applies to P7100 pumps (94-98 12 valve)

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96 SLT Laramie CC 5spd, 3. 54, no muff, no cat, 5"turn down tip
. Member NRA/USPSA

[This message has been edited by Deezul 1 (edited 01-14-2001). ]

 

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That's correct. The alan key at the top of the afc housing is 7mm or 5/16 & moving the star wheel towards the engine increases low end response but gives more smoke.

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Piers, BD engine R&D

 

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so ,correct me if I am wrong, when i am turning the wheel towards the motor, iam actually decreasing fuel mileage because I am allowing more fuel in at lower rpm?? If this is the case then this will only benefit heavy towing?? Also when I advance the wheel towards the motor I starts to disappear beyond the hole(@30 clicks). Do you guys, who advance, take the pump cover off and go beyond that hole??? THanks

 

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I turned mine til the spring was so loose that I could slide it with the screwdriver.
It never got out of reach from inside the hole tho. Then I slid the plate full foward and WOW ! smoke galore then. Now I have moved the wheel back against the spring with some tention and it rides fine with little smoke. The wheel position seems to act like an accelerator pump on a gas engine. When you mash the petal, that is when the extra fuel is given. I may be wrong there but that is how it responds with me.
Ron

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97 3500 dually, ext. cab p/u,5sp,2wd,3:54,245/75R16,
straight pipe,105k mi. star wheel loose,plate slid forward, I like it
Ron

 

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Rednut, I ran mine 60 clicks, (Yes, SIXTY!), and no reduction in mileage. Still got some tension on the spring, too. Just a little bit of smoke on hard accel. Made a HUGE difference in driveability. I am about to slide my plate forward, so I'll most likely have to back off on the 'wheel.

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'96 Regular Cab, 116. 5K, SLT 2WD auto 3. 54, Vista topper, Pillar-mounted Autometer Boost/Pyro, transmission temp and oil pressure guages under dash, starwheel spun

 

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Ok now that we have moved the AFC wheel and know what it does, how about the stock plate? I was told that moving the stock plate wont gain as much as an aftermarket plate because it wasn't designed like the aftermarkets are. If you can get nearly as much as aftermarket results, why not slide the stock forward for a while until funds come available. I would be installing the 235/605 plate, but if the stock plate would give me 100 lbs of torque, I will slide it forward. Maybe this is a question that Joe or Piers would answer. .

Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, Pre-Turbo ISSPRO 3" Pyrometer & Boost Guage,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks,Amsoil Dealer,Straight Piped

 

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Rick,

Slide the plate. It's worth 40 to 60hp more in our pumps. That put's you past the 230/605 #12 plate, for free. #ad
#ad




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Money Sink - 96, 5 speed, HX40-16, TST #11/280 slid 3/4 way, 300 HP Injectors, Scourge BD 4200rpm Governor kit, McLeod.
4", CATless, straight out back, chrome turn down.
ISSPRO Pillar, Delvac 1 & Amsiol, K&N, Mag-Hytec, 3:54, Michelin 235s on Alcoas, Rancho 9000's, Valentine One.
#11 plate days are numbered, custom grind in hand.
Dutchmen 27' 5th Wheel.
GoldWing.

 

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take the plate out and use a file to make the slots even longer and then set it full forward. saves the price of the kit. i would have went this route but had already bought the new plate on which i used a file on to get it to set more forward. i would get the brass elbow used on afc though. watch your egt's ,,especially if your towing. the 12 valvers are easier to bomb than the 24's with all the electronic gizmos,,kinda wish my '01. 5 was a 12v,,,i guess i will figure the new one out,,alot more expensive to bomb though

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94 2500 4x4 SLT,auto,182,000 miles,3:54,brilliant blue/silver,tst 250/635 set full forward,star wheel wide open,air box ported,pump turned up 20%,k&n,gauges,cat gutted,
2001. 5 3500 4x4 q-cab slt,auto,6000 miles,3:55lsd,brite silver,stock (for now)both have 12k hitches&15k's in the beds,30ft fourwinds 5er,(MY RAMS) http://albums.photopoint.com/j/AlbumIndex?u=1360183&a=10142301

 

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Rednut, I turned mine up. I dont know how many "clicks". It was a real PITA to see in there while the screwdriver was in there too.
I DID lose some MPG's, and had beaucoup smoke. (I think I lost the MPG's because I liked to see the smoke) I cut it back some, and have a happy medium now.

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98 Quad cab 4X4 2500 12 valve,5 speed,3. 54 rears, 8' bed. Boost and egt gauges but basicly stock except for a "properly adjusted" AFC. Cat in the garage. Uniden HR 2510, Texas Star 1200 amp. 59,000 Mi as of 10/21/00.
NRA life member. High power/IDPA.

 

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I slid my plate and housing this weekend. Wow! What a difference! Wakes that beast up, that's for sure. And, I DID NOT turn my starwheel back. As long as I keep my foot out of it, (actually I have to, my transmission's slipping), smokes not too bad. The 70 mph throttle tip-in is just awesome. Instant gratification! #ad

 

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I just had my truck on the dyno with the only the stock plate and AFC housing slid forward and the star wheel adjusted. I also have the K&N RE-0880 and a straight exhaust. The truck dynoed at 282. 8 HP. That's not bad for not spending any money. That's better than a 24 valve with the PE on 3.
I will eventually drop the money for the 370 injectors and a #4 plate but that's in the future.
I'm definatly happy with what I have for the time being.

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Curtis Harris
1997 3500 Club Cab
"CASPER"
Check out the Lone Star TDR

 

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With adding that amount of fuel, don't you have to do something to the amount of boost? Doesn't the after market cam plates come with something that changes the boost?

Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, Pre-Turbo ISSPRO 3" Pyrometer & Boost Guage,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks,Amsoil Dealer,Straight Piped

 

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282. 8 hp at the rear wheels **** thats awesome.
How much boost and EGT'S did you have? What kind of fuel mileage do you get with it set that way.

Thanks
#ad
#ad
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D McGrady 1996 Club Cab 6BTA 5. 9 12 Valve All Stock Except K&N and Wrangler A/T 305/70/16 136 K and going strong.

 

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1st post,
Ran the s-wheel in about 30 clicks, little more low end power. Question is would it be safe to slide the stock plate any before I add egt,gages?Or would the auto transmission fail?

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96 3500 Feline deceased. Electric start
Ready to upgrade. 86K. Rtoe,3. 54,Ext. cab.

 

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This response may open up another discussion. I called TST Products to ask a couple of questions and one of the questions was if you start adding fuel what do you do with the stock boost. The answer that I got was if you added fuel you also need to do something with the boost. It needs to be changed from what it comes out with stock. .

RIck

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, Pre-Turbo ISSPRO 3" Pyrometer & Boost Guage,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks,Amsoil Dealer,Straight Piped

 

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My boost went up by itself, after sliding the plate and housing. I used to get 18-19 lbs. Now I get 22-24, before transmission slip. More fuel means more boost, I guess.

 

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I can't answer the EGT and Boost question because I don't have gauges yet. Honestly, I had no idea I was pushing that many ponies. Guess that's what the dyno is for. As far as mileage is concerned, I'm consistantly running 18 to 19 mpg. I didn't notice a drop in mileage after I did the mods. You have to take into consideration that I've got a heavy steel brushguard and a rear bumper that weighs in the neighborhood of 200#. That also affects the mileage.

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Curtis Harris
1997 3500 Club Cab
"CASPER"
Check out the Lone Star TDR

 

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Once you've moved the stock plate, just disconnect the line from the afc housing to the wastegate. Plug the open line & tighten the clamp back down & cap off the wastegate. Free boost increase. You've got to love these. #ad
#ad

 

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Just put in a TST #8 (230/605) and I'm getting 28 lbs of boost. Star wheel is turned about 25 clicks, I am going to go another 10 clicks this weekend. Little to no smoke right now.

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'98. 4 Bright White Quad Cab SLT, 2WD, 12 Valves & the BIG "P" Pump! 3. 54, AT, Trailer Tow PKG, Camper PKG, OEM Cab Lights, TST #8, Three pod A pillar gauge mount, EGT pre-turbo, 4" Exhaust Turndown, K&N Air Filter, 5th W. Hitch, Pace Edwards Roll-Top, Tint, 265 Michelins and turbo silencer ring AWOL!

23,876 miles - 1/7/01

[This message has been edited by tschwab (edited 01-24-2001). ]