LOL roll with a flat bill on sideways and no one would think twice


...can't wait to see what the new mods do

 

and you have to have it more advanced as well i suspect.

so most of the pressure is from having to move the fuel and lifting the pintle so quickly, not so much from the pintle closing the hole with the spring pressure.

so what part of the db2 doesn't like extra pressure?

 

I have the timing @ 10* on this pump, same as the last.

the DB4 is just a superior pump by design.... the DB2 just cannot inject fuel as quickly as a 4 plunger, hence cannot reach the same injection pressures.

 

My truck doesnt smoke one puff except for when it first starts up cold, and 2.5 points of compression isnt going to cause that much smoke on its own. I think its your stg 1.5 injectors and that pump, while injection pressure plays a role (And the fuel through the injector orifice), I bet it has more to do with spray pattern of your sticks... Might be part of your issue with the DB4 (while not as bad) smoking as well. I think you should put my spare BB codes in and see what it does with that pump, that way you can at least count out the injectors as an issue.

On that note, I maxxed out my WG tonight, and saw 22psi for the first time, but its way up there, 3400 rpm. I think my engine flows just a little bit more air than yours does, with the slight displacement advantage, and thats why I only see 22psi maxxed, Of course, I could back the torque screw out and see if that adds anything as well.

But as long as we are getting off topic a bit here, I think your right on the money as far as these turbo's are concerned. The exhaust wheel is a bit small and thats why they work alot better with more flow (RPM). Now your going to get me shopping around for other turbo options...

 

2.5 points of CR? Mine is 3.5 lower at the least..... Also, my injectors are exactly the same as yours, Ken confirmed that.....

People keep saying my 'smoke issue' with the DB4.... the IDI guys are the only ones that see it as an issue, the 12v guys thought it was perfectly normal. That being said, I have also confirmed I have a restrictive charger... this will cause smoke haze at higher fuel output.

You only see 22psi maxed because my turbo kit is better than yours :P

Bring the BB's down br0. Actually you could give them to amber saturday. I'll throw them in.

As for shopping around for different turbo, you should put a backpressure gauge on first. I'm nearly 1:1 at my current fuel level.... and you're not pushing nearly enough boost or power to need a bigger charger yet. I would suggest figuring out your fueling situation first, and then buy the appropriate charger.

EDIT:

and about your truck not smoking... when I watched you leave H&H the other day, it hazed the whole way up the road, yes even when you weren't punching it. I think you just have trouble seeing it from your mirriors because its thin.

Same thing when I followed you to your house the day you welded my radiator. Almost a constant minor haze.

 

Alright, enough with the threadjack... back to my pump...

Ill get some more info on it as soon as I get the rotor back...

 

buuuut... i want more info noooow...

Have you decided if youre going to modify leaf springs?

 

Racin, are you planning to use a 6.2 spring in your pump? and just what effect does it have. I thought it keeps the pump fueling longer (assuming it can get the fuel, for instance your fill ports) or does it just increase the maximum rpm? Also, did you decide whether or not you plan to modify the leaf springs?

 

The plan for the 400 pump is to run the stock stroke on the plungers for reliabilty, and as far as RPM's goe, I think ill keep them around stock on that pump as well. The only way I would put in the 6.2 spring is if A) I was running a fairly stock DB2, and I was looking for all out hp on the dyno or B) I was building a drag IDI that needed some RPM to complete the 1/4 mile still pulling... 4k on an IDI is totally useless other than those two reasons... At least thats how I feel about it.

 

Got ya, i was just curious as i knew you wer pushin some higher revs on your turbo cal and was wondering if you plan to do the same on this one.

 

Na, my truck hardly see's over 3K, not really any point to go north of 3400 unless Im after the numbers for bragging rights... All the work is done between 1500 and 2500...

 

I know P-pumps are totally different but what is the difference when guys do higher gov springs on those? Does it add more fuel on a P-pump or does it function pretty much the same?

 

it just keeps the metering valve from being open at high rpm thus less fuel makes it to the pistons.

in an injection pump you set the engine speed with your foot. the difference between what you set and the actual engine speed determines how much fuel is injected.

 

I understand that part. Lol. But I just know Cummins guys add a 4k gov spring and didn't know if it had the same affect on there IP and it does on our IP?

 

Having put a 3200 spring in my VE cummins, I can tell you that the spring changes the fueling all across the rpm range, with more fuel given per throttle position. However, this isn't some kind of voodoo magic, by putting in a stiffer spring, you are forcing the governor to react faster to changes in throttle position, IE, what rpm you are calling for, and the gain in max rpm is simply due to the stiffer spring requiring more leverage from the governor to overcome.
The reason this makes such a big difference in a mech cummins, VE or P-pump is the stock governor setup is overcoming the governor spring at around 2600, and with a VE, 2800 is all you are ever going to get, with the change in spring it start defuelling at around 3200, with no linkage/throttle mods.
That is another of the things the VE guys do. My truck has no high idle screw at all, and the base idle is adjusted so that the stop is 1/4" from the boss that the screw goes in, vs the nearly 3/4 it was stock, so I have considerably more travel than stock, and at max throttle, which is now limited by cable travel I am putting considerably more tension on the spring, allowing me an extra 400 rpm over what just the 3200 spring would do in it's own.

I really don't see much point in changing the spring in an IDI, the extra bit of rpm you want can be gained soley by adjusting the throttle stop.
Besides, if memory serves, a stock 6.9 pump is supposed to spin 3750, I'd have to look into the shop manual again. My 6.9 will spin 3750 all day any day of the week, but, it is not a stock pump.