jstone44720

I've been reading and researching, and had a question on the title to this post: If delivery valves add power/fuel, and injectors add power/fuel, why does it seem like folks are always swapping injectors before delivery valves? The delivery valves cost less than even the basic 370 marine injectors which are considered cheap and dirty. What gives?

jstone44720

No good reasons?

nascar mark

Most buy inj's before DV's due to inj's wear out or you could you say, they tend to fall off (mileage and pressure) over time and DV's don't. Also you can gain mileage with an inj and DV's you can't.
Hope this helps.

patdaly

I'm no expert in this, but I believe you really don't gain much from DV's until you out run their ability to deliver, I.E. the Injector is the final hole that the fuel must pass thru. Increasing the holes/sizes or raising the pop pressure would add fuel.

Someone please correct me if I am wrong.

Diesel Dave2

If you get a set of DV cheap...they will help with your 175 pump..I'm not sure what the bottle neck would be if you have the stock 191 injectors..I installed 215 injectors with LC and a very tight AFC.The 215 upgrade sure helped the response,installed LC after..If you get a set of 181 DV,I would use the 131 seats...I tryed 181 DV including the 181 seats and my power was worse than having stock 131 DV and holders..Would like to try 0.22 DV and 131 seats one day...I think that would be a good balance between LC and 131...I'm still experimenting thou..

jstone44720

The falling off makes a bit of sense. At 238k I believe mine have probably given up something. From the other description of injectors being the bottle neck, I guess I had the wrong impression of how delivery valves worked. I thought bigger DV's would lengthen the time the injectors are firing more than just open a bigger hole. Thanks.

If injectors are really the place to start, is the Bosch OEM part #0432131753 a good one? I can only find a few sites selling these as 330 HP. Are they meant for automotive 12v engines? I also found a part number for a 300 hp Bosch injector. P# 0432133864 is listed as a 300 hp injector. Any thoughts on either of these?

infidel

Pat is right, very little gain from bigger DVs unless you also have aftermarket injectors that will flow more fuel.
On the other hand the stock DVs will support higher flowing injectors, to a point.

jstone44720

Thanks to the lot of you. The second injector part number for Bosch 300 hp injectors is a good automotive injector with the correct spray angle - info from a service/tech support guy at a reputable diesel performance vendor. Any ideas what the real HP bump would be for a '94 with a plate, tweaked afc, and boost elbow?

patdaly

Don't know what the HP number is but the tail-O-meter will be pegged.

It doesn't take much to really wake these puppies up, the Torque gain is more the reason, feels like the hand of God is pushing you.

jstone44720

I love that feeling ^^^^^. When I take jets out to Chicago I'm reminded of my truck from 50 mph to 115 mph. Thanks.

Mike Holmen

We picked up a good 20-25psi of boost in Tate's with a set of worked over 181 DV's. To run those DV's you really need twins, the stocker has no hope of clearing up the extra fueling.

Injectors are a decent upgrade, the 370's haze and smoke more than the 215's injectors, mostly due to the spray angle. Ran both the SDX 5X12's and 5X14's, both very decent clean sticks. Been impressed for the quality and their reasonable price. I have a set of 7X15's 148 deg coming, but they are more of a sled pullin/dyno bustin stick.

Lots of extra fuel available in the pump, if you know where to find it.