12 Valve Performance

[Randy J]

Not to start a war, but it seems to me a computer timing box, new injectors, and you have 300 useable horsepower from a 24 valve. What's it take to get that from a 12 valve? Just a fuel plate? New injectors? What does a governer spring kit do?

Just curious

 

[Don M]

to get 300 on a 12 valve... you can do that with plate and exhaust.

I got 326 HP with a cam plate(#11 slid forward) and 4" exhaust.

Still had the stock air box with a K&N filter.



Don~



oh yeah, I bumped the timing 1. 5 degrees.

 

[Randy J]

Wow, that's pretty impressive. I notice the DD Stage 3 injectors only added about 20 horse power, after the plate.

By the way, how about EGT's?

 

[Don M]

The stock (215HP) injectors are really quite good. EGT's on my rig are totally controllable. I never get over 1400 and that is for a very short burst. I can hold it to the floor on the HWY and the governor will start cutting back fuel and the EGT's stabilize at around 1000.

Towing a 8000 lb. cargo trailer EGT's climb faster, you just have to watch how fast you accellerate, after your speed is up the EGT's drop back down.

Tons of smoke on take off. I love it.



After the DD'3 and K&N filter I got roughly a 2MPG increase in fuel economy.

The truck has better acceleration with the DD3's. They also started my clutch slipping. The clutch has about 200,000 hard miles on it though.



Yes, it seems the DD3's only added a total of 20 HP but that is somewhat deceiving. The 326 HP number before the injectors was on a cool day with the intercooler soaked in water from a hose with fans blowing all over it. Outside air temp was around 70.

The dyno run with the DD3's was very hot outside air, no fans, and the outside air temp was 103. . I had some cruddy Texaco fuel as well.

I think I picked up around 25-30 HP. Midrange seems better also.



Randy, remember the bombing may be a little easier on the 24 valve (e. g. adding boxes and so on) but the 12 valves are still the king of power.

Right now you can only do so much with the boxes and injectors.

I think around 475 HP without drugs. 12's can get to 500 and some have gone on to 600.



I think the 12 valve 5 speed trucks are the most reliable too.



Don~

 

[HoleshotHolset]

I agree with the P7100 being more reliable than the whole VP44 setup. People are putting the P7100 on 24-valve engines, but I have yet to see anyone put a 24-valve VP44 on a 12-valve engine.

Want more power from a 12-valve? Put in injectors, delivery valves, adjust/replace a few springs, loose the exhaust and do it all for $600 or so. One box for a 24-valve costs darn near that much. I've driven a 24-valve for more miles than my 12-valve and I like the benefits of both. But for me... more HP with less $$ and simple hand tools is the HOT OPTION!!



Matt - fan of all diesels, owner of the best.

My 100th post!! JOY!

 

[John_P]

Randy:



To give you more "numbers" on a 12 valve here is a

progression of my "mods" over the last year or so:



1. With a TST #6 plate only, stock exhaust: 225 H. P. /625 TQ



2. TST #5 plate, 370 injs, gov sprg kit, afc sprg kit

modifications to the P7100 (higher fuel, RPM)

3 1/2" exhaust, no cat 381 H. P. /1069TQ



Both of these readings were on a "Mustang" Dyno

at Scheid Diesel.



The "governor spring kit" raises the RPM of the pump

from stock (2500-3000) up to 3500-4000 and beyond.



Hope this has helped you some.



-----------

John_P

 

[Forrest]

Cost wise on a 12V, wouldn't you 1st go as big on the plate as you can before changing injectors? The injectors are so much more expensive than a plate. If you've max'd out on the plate & you don't have enough umph, then go to injectors & pump mods?

 

[Randy J]

Is there much benefit to the governer spring kit? It would seem to me once you reach about 3000 rpm, you're pretty much out of the horse power band anyway.



Thanks for all the great information.

 

[sewman]

Randy: if you run a bid plate w/stock inj mainly anything less than 215 your overworking your pump alittle & can cause failure.



Forrest:Rpm's are always nice,try drag racing shifting shifting @

2500rpm, I have & lost to a ratty ole Ferd gas truck

put in gov spring kit & DD3"s & he seen my lights & couldn't even catch me on top end!!!

 

[Forrest]

I'm 99% of the time pretty easy on it, but on those rare occasions where you need it, the gov spring kit makes all the difference in the world. Before, fuel was getting limited about 2300 & I squeezed every last drop @ 25 to 2600. Now, I can rev easily to 3200, which I've never exceeded. You can carry the power so much farther with the added rpm.



The rpm rises so fast with the added power that when you shift @ 2500, you're right back on 2500 again real fast. Very frustrating. sewman has it right on.

 

[gitchesum]

Money?? What money?

I know it ain't 300hp but I pulled a 283 on a DynoJet with a K&N Filter, starught exhaust and the stock plate slid forward. I will say that the HP Dyno sheet looked like a gasser dyno but it was still up there. I might try a plate out and see how that powerband changes.

I might even let you drive it in Kerrville

 

[drawson]

4000 RPM is

I just got my governer spring kit in and I LUV it. Unlike Forrest I have seen 4000 at least once a day since installing it This extra RPM helps to take care of the big gear ratio differance between 3rd & 4th. I think the engine actually sounds really good up there in the RPM range.



AS far as getting 300 HP in a 215 HP engine all it takes is a #11 plate slightly forward or the #11 w/ a 16 CM2 housing will do that also.

 

[sewman]

Drawson:What's your top speed with the 3. 54 gear @4000rpm?

Bob

 

[drawson]

Top Speed

sewman,



I haven't found that out yet. On one hill putting a new subaru WRX in it's place I was doing 115 when I looked down at the speed-o This was all done in a 55 MPH zone



WIth the stock governer set up it would only goes 105 or so. From where I was there I would say she should go 125 or so. But it was pretty floaty at 115

 

[HoleshotHolset]

I dunno if this applies totally to this thread or not..... but..... when I first got my truck it would shift at 2500rpm at WOT (with lots of sputtering)..... I thought that was too low. One day I had OD locked out and I hit like 60 mph in 3rd gear (3000rpm)... . ever since then the truck has been shifting at 2700rpm or maybe a little bit higher..... with less sputtering.

I don't know if the governor setup just needs an Italian tuneup every now and then... . but this is the cheapest governor spring upgrade I've ever seen.



Matt

 

[Hammer]

Exhaust system adds power?????????

Ya know,every once in a while you'll see a statement like this and I have to chuckle,,Seems like there have been a few who have tested exhaust systems and most recently Joe D. wrote an article that was in very good detail on how an aftermarket exhaust makes now NOTICABLE gain hp(If I remember the amount was a BLISTERING your pants off 7 hp),,It will help the EGT's though,but,show me somebody that says the exhuast made a seat of the pants HP improvement and I'll say BUNK!!,,300 Hp is attainable WITHOUT the addition of a plate at all and since I know somebody is going to dispute it Randy,search for MY6EATSV8's posts because he was over the mark you question with all stock components,,He does have some interesting tricks and myself have found them a worthy addition,,The governor spring kit is not in my truck I used what My6 gave me to do and can rpm at will,now,I can not reach the orbit shots these cats with it can,but,in a low rpm motor why spin it into orbit and into valve float that kills hp and torque,,Not to mention the wear and tear on the valve train itself,,Off our recent dyno day out here my truck made respectable HP inside the range the motor is designed to run and was quite happy,,The only aftermarket equipment on my rig is a TST #10 plate set slightly rear of center,My6's rpm and washer trick,Amsoil air filter in the stock box minus the fender sleeve,a litttle timing advance and no cat and muffler all stock pipe(3"),,My best numbers on "THE HUMBLER" the DYNOJET dyno we used were this... . 324. 5 hp at 2400 rpm and 812. 8 ft lbs of torque at 1800 rpm,,While I realize that many others are making much more I was quite happy and feel that the motor is very efficent,,People may dispute what I have posted in the numbers,but,we have the charts and there were many witnesses to my pulls and if they are non-believers they can ask any Mason-Dixon TDR members that were in attendence,,So if its power you seek do a little research and you'll see and find what you want... ... "REAL TRUCKS RATTLE"