Hey guys,

I think I'm ready for an aftermarket prom for my '94 and an auction vendor who lives near me here in Texas has a new one with 99mm3 fuel output. My plan so far is to dyno my truck before the prom and after to illustrate any power gains in a dyno graph. I just have to cobble some sheckles together first.

So, how does a pump that is only capable of about 84mm^3 make 99mm^3 by changing a prom?

Proms increase the fuel delivery by calling for the optical to count more slots per injection event, the same way other chips increase delivery from 63mm3 to 83mm3. I will be increasing it from 61 mm3 to ? Which will be verified on my scantool.

That's just it. What you read on the scan tool is what the Prom is requesting...not necessarily what the pump is delivering. The physical limits of the pump get in the way here. Your prom could call for 1000 mm^3, the pump can only deliver about 84 mm^3 maximum.

I think RJ may have something, I was looking on the Stanadyne site a while back and our pumps have a max HP rating of 250 hp. That is one reason I question the reality of some of the EPROM out there that promise 80 hp because if my math is correct if you take a 195 BHP engine and add 80 HP you now have a 275HP and that is 25 hp more than the fuel pump will support if Standyne is right. So where did the extra HP come from???? I know you could be a bit more efficent but is that real. TDG maybe the guy who would know?

There must be a max fuel rate the pump can produce. Does anyone know for sure what it is?

I just posted it.

Tex talks about increasing fuel output to 90mm3 and wester's garage has a reflash for 93mm3. I guess they didn't hear it couldn't be done.

Westers is selling a new pump set to 93mm.
rj, I read what you posted but is that a number your thinking or a number put out by stanadyne?

They're changing something in the pump, most likely the cam ring, and they're pairing it with what would be 83mm programming to get that. You can't get that high (99) without digging into the pump.

QM, If your going to do before and after dyno's. There really isn't much point in arguing about what stanadyne says the pumps limits are. Dyno's don't lie.
RJ your sig says 223 hp at the wheels if thats true than the 250hp limit stanadyne claims is not true or you'd only be losing 27hp to drivetrain. The 4l80e cost between 35 and 40hp by itself not to mention the accessories. You'd have to be making at least 280hp at the flywheel to get 223 to the wheels, so the 250hp cannot be the physical limitation of the IP.

I think RJ may have something, I was looking on the Stanadyne site a while back and our pumps have a max HP rating of 250 hp. That is one reason I question the reality of some of the EPROM out there that promise 80 hp because if my math is correct if you take a 195 BHP engine and add 80 HP you now have a 275HP and that is 25 hp more than the fuel pump will support if Standyne is right. So where did the extra HP come from???? I know you could be a bit more efficent but is that real. TDG maybe the guy who would know?If the pump will only go to 250 hp then how did RJ get his dyno numbers at the RWHP???? it appear that RJ and other has found some hidden stuff in these setup that the manufacter didn't want to claim

Actually, Stanadyne's website (http://www.stanadyne.com/new/ppt/ppt_dselecpump.asp) says the pumps capabilites are to 25BHP (19Kw) per cylinder which would only make 200 BHP on an 8cyl pump. Which is pretty much what these trucks do stock. As many of us here have proven on this site, you can far exceed this with reprogramming and other methods.

I agree with TDG, those must be actual tests based on specific engine configurations, not taking into account turbo's, large exhausts, injection timing. My truck and many others are making way over 200 flywheel HP. So somewhere were not getting all the info from Stanadyne. There's a big difference between results based on testing and the actual physical limit of power obtainable from each injection pulse.

The numbers in my sig are real. The data is posted in the FAQ's at the top of the page.

Note, I never said that 250 hp was the limit for these pumps. 16ga said that based on Stanadyne's web site, which I've seen as well. I said that 84 mm^3 was the physical limit for these pumps. TDG has shown cam ring changes that increase that physical limit and now Wester's is advertising one with increased physical limit.

My point was that no chip can magically cause one of these pumps to deliver 99 mm^3. QM needs to spend more time learning how these machines work than dreaming about numbers that aren't real.

As for my power level, I posted in another thread (with all the justification) that my engine is probably making 275 hp and over 490 lb-ft at the crankshaft. That is clearly more than Stanadyne advertises. In fact, bigger numbers will be posted by this summer. Mark your calendars.

The numbers in my sig are real. The data is posted in the FAQ's at the top of the page.

Note, I never said that 250 hp was the limit for these pumps. 16ga said that based on Stanadyne's web site, which I've seen as well. I said that 84 mm^3 was the physical limit for these pumps. TDG has shown cam ring changes that increase that physical limit and now Wester's is advertising one with increased physical limit.

My point was that no chip can magically cause one of these pumps to deliver 99 mm^3. QM needs to spend more time learning how these machines work than dreaming about numbers that aren't real.

As for my power level, I posted in another thread (with all the justification) that my engine is probably making 275 hp and over 490 lb-ft at the crankshaft. That is clearly more than Stanadyne advertises. In fact, bigger numbers will be posted by this summer. Mark your calendars.
And you know RJ I was not questioning your dyno number's, I try not to do that to anyone. I was asking a question in hope someone who knows could explain. SOunds like another one bites the dust when it comes to the limits as set by Stanadyne I guess. Can't wait to see bigger numbers?

"QM needs to spend more time learning how these machines work than dreaming about numbers that aren't real."


:eek: No offense to anyone, but iv learned a lot more about these trucks from reading QM's post than i have anyone elses, i think the guys knows what he talkin about hes just a little power hungry like all the rest of us:ro)

RJ, I find your #'s to be impressive and I do not dispute them. Which brings me back to what I said before dyno's don't lie and you can't get 223 to the ground from a 250 limit pump, so the info from Stanadyne is based on some set of standards unique to them.
As to QM, he is the bravest experimental tweeker I've seen for the 6.5 always looking for a new way to get our trucks to the next level. His first post simply states that he found a new prom and was going to perform pre and post dyno data on it. To me that doesn't sound anything like dreaming about numbers. That sounds like R&D at its finest.

I agree with RJ on his post, numbers don't lie. If thats what the stock pump can make efficiently then thats what it makes, but once you consider how you burn what it makes then thats where the differences will come in. Stock pumps mean stock set-ups and we are not playing with stock set-ups here, we are talking modified. Add a little more boost and a little more 02 and we can make them HP numbers alot larger.

I have talked with "the man" at Westers, as a matter of fact he did my ECM for me while i waited and watched and seems to have done a fine job too. This guy went out after doing my reflash and purchase his own 97-98? 6.5TD just to see what he could do to it with the programming so he can preach what he sells, since that time he's been looking into the 92+mm pump. I was there three or four weeks ago, the pump wasn''t ready yet. The pumps are not being made or produced there, they will be made from a fuel shop, possibly TDG's place of employment but i can't confirm this, they might come Japan for all i know.

All i'm saying here is to forget the max 84mm fuel rate of a stock pump because the pump is no longer stock right? If it was stock you'd buy it from your local dealer or parts store for less money rather then purchase one from a performance shop such as Westers or any other performance shop.

A stock pump as advertised can't put out more fuel than its advertised to put out in a stock setting, change some peramaters and it will make a little more, tweak the pump itself and make even more.

Anyways whats all this huff about Westers anyways, i never heard mention of them before i got my reflash done there? Sounds like they're a leader, not a follower.:ro)

They're changing something in the pump, most likely the cam ring, and they're pairing it with what would be 83mm programming to get that. You can't get that high (99) without digging into the pump.
But someone will always be there to claim it can be done, and someone will always believe it. Just like the 80HP chip for the 6.5...

The PCM calls for more fuel than the mechanical limit, is it possible to increase that mechanical limit. Ie regrinding the cam ring, or a combination of internal tweaks? I bought a back up 5521, and I'm not afraid to modify it.

QM, I am ready for those numbers from the dyno. Keep up the research.

You should be...............

I bought it for $23 on the bay. It was purchased for the sole purpose of taking it apart.
If I don't push the envelope who is? I'm really glad some of you guys are interested in what could be. All I hear "officially" is the status quo. all I'm interested in is more go.

[If] The PCM calls for more fuel than the mechanical limit, is it possible to increase that mechanical limit. Ie regrinding the cam ring, or a combination of internal tweaks?If the PCM tries to exceed the mechanical limits, you will certainly run into operational problems. Big difference in someone who knows how to write PROMs, and knowing how to make one work on the vehicle. Idealy, if you change the pumps internals to get more fuel, the best way would be to program a PROM to match the pumps new capabilities. This could be done simply by calibrating the pump with whatever changes you made inside. Then you would have to do a lot of draws at different RPMs, Advance, and Pulse Widths (being FSOL energized duration, not CTIME) and put it all into a data base. You could then use this data, along with the original programming to design a matched set pump and PROM. Simply putting 99 into the PROM just won't cut it.

If you notice my sig, I'm still running a 5068 cam ring. This is a cheat to make the pump actually deliver more fuel quantity than the PCM 'thinks' its actually delivering. However, due to programming limitations of my L56 PROM:thumbsdow the difference is minimal. I still plan to remedy that soon with an L65, but the best way would be as I described, sit down with someone who can write a PROM to match the new fuel curve.

TDG,

So are you saying on the OBDI trucks we just have to find an L65 PROM and not replace the whole damn PCM? Would it be better to get an aftermarket prom (like Heath or Kennedy) that was specifically for an L65 with the same features as the truck currently has? I am just itchin to get rid of the rest of the EGR electronics in my truck.

Yes, the prom contains ALL the programming instructions for the Engine and Tranny. If you want to get more fuel/power, then aftermarket is the way to go. I have no personal experience with any of the Aftermarket ones, but I've heard good things about both Kennedy and Heath. I would prefer Kennedy, he's on the site, so you can always get ahold of him ;)

An aftermarket PROM can push you to the mechanical limits of the pump, if you want to go beyond that (~84mm) you have to make some internal changes in the pump.

If I don't push the envelope who is? I'm really glad some of you guys are interested in what could be. All I hear "officially" is the status quo. all I'm interested in is more go.
There is a difference between pushing the envelope and talking about pushing the envelope.

The experiemental tendencies of Mr. QM are good. If he would take my advice and learn more about how these machines worked instead of dreaming about magic proms, he'd waste a lot less of his time and wouldn't go down so many dead ends (and wouldn't mount oil filters upsided down). My comments are never meant to belittle, but to try to help people learn. If you refuse to learn, that's not my problem.

As for pushing the envelope... anyone care to enter a loaded hill climb contest with me? You can read about how mine performed last summer (if you have a membership) at http://www.thedieselpage.com/features/pulloff04.htm. You'll be able to read about more performance from my Suburban there later this year. Then we'll talk about pushing the envelope and, what was that called? Oh, yeah. The status quo.

Ron, I give you credit for the hill climb and showing a good time and mph but your truck is set up like many others and running similar powered same engine trucks up the hill will not prove much. What did JK's old 96 do on the hill climb, if you remember? I think your truck is running same power levels as his made except he had a different turbo maybe.
How much power to you expect the burb to make after the new engine? Are you going to a better chip to get more fuel and boost into the motor?

My truck was set up like many others. That's all changing.

JK's 96 was 1 second quicker than mine up the hill. He made 48 mph at the mile, while I had fallen to 42 mph. About 2/3 of the way up, I was at about 47 mph. Had I allowed a shift into direct, I think I could have held or even gained speed. Now, the trailer weight was 10,460 lb when JK ran the hill. It was 11,920 lb when I did.

I don't talk about numbers in a speculative fashion, as others do. I always say, "The proof's in the puddin'!" When there are numbers to report, they will be reported.

Ronniejoe, Get on the hill before the temps and the wind kick up!! Looking forward to seeing how you do this year. http://www.dieselplace.com/forum/images/smilies/rockon.gif

So, if I get a replacement prom, I know most of the vendors want to know the code on top of the prom. No problem. But if I want a prom that is an upgrade from the L65 prom so the EGR crapola is ignored, howinhell do I do that?

Don't know how it would work with a chip, but I just swapped to a L65 PCM from the junkyard, to get it reflashed I read the vin of the PCM with my scan tool and used that VIN to have that PCM flashed for a H/O 65

HEY RJ
I would love to be there to watch you and others pull that hill, never know who might show up. Sorry can't bring my "pulling" machine it only goes 15 mph but can handle over 300,000 lbs. Now that's pulling (or pushing) your weight around. LOL ya have a good day, ya hear.

I can't swear to the 250hp number as I pulled it out of my gettting older by the day head which I should know better and TDG that 25BHP per cylinder rings true, still it bring us back to the fact that there is limit to what these pumps will put out unless like TDG say you "dig" into the pump. If I remember right there was discussion way back of at least on fella considering changing the pump physically to try and increase fuel supply.

RJ,
yupp you did bog down I was also forced to back off to keep in position behind your Suburban. I also think Ron you would have don better if you could have been the first one on the hill before it got too warm.
BTW anyone know if there going to be a pull off in Salt Lake or will that come at another place or time? Last year I enjoyed just running in the chase truck.