Engine/Transmission (1994 - 1998) Thoughts on Injector Upgrades

[Joe G.]

Sliding the plate has no affect on timing. On these mechanical pumps the timing of the start of injection stays the same regardless of how much fuel you give it.

 

[Reddog1]

Sleeper - Are you running stock injectors?



JohnE - Have you dynoed, and if so at what HP?





Wayne

 

[JohnE]

<blockquote>Reddog1 asked:

JohnE - Have you dynoed, and if so at what HP?</blockquote><hr>

I have dynoed with governor springs at 12. 5&deg; (stock) timing and at 20&deg; timing. (I've haven't dynoed the #4 plate thinking the stock transmission will not be up to the task. )

gsk w/ 12. 5&deg; timing: 154 hp @ 2,800 rpm and 380 ft-lbs @ 1900 rpm

gsk w/ 20&deg; timing: 176 hp @ 3,100 rpm and 380 ft-lb @ 1900 rpm.



I have the #4 plate fully back. I get hit 1500&deg; on the pyro when hot rodding in the 3k rpm range.



JJW-ND has a 96 manual and we did governor springs together. He dynoed 345 with just a #11 plate. Adding governor springs, 16 cm&sup2; housing, advanced timing; and a new thicker head gasket put him up to 360 hp. He can tow without any EGT problems by keeping the rpm down, but hot rodding and 3k rpms and EGT will go right to 1500&deg;

 

[LSMITH]

Man, it seems to me that ported heads and or a cam would help you guys tremendously. The 24V can make 350 HP and still have EGT along the lines of stock with just a muffler delete for airflow mods. From what I have gathered the 24V head flows quite a bit more air, but the cam is pretty close in profile to the 12V cam.



I am at or slightly above 350 RWHP and can only break 1350* when at WOT for over 20 seconds on days with temps above 85* and humidity at least as high.

 

[Reddog1]

LSMITH - I envy your EGT's. I am still chasing mine. I guess it's just a matter of time. OH, I mean money.





JohnE - Santa will be delivering the timing tools. I will start with that.



Sleeper - Are you running stock injectors?





Wayne

 

[Sleeper]

Yes, stock. I could go with bigger injectors but that would just mean more fuel => more heat. A better spray pattern might mean better fuel efficiency but I suspect the gains would be fairly small.

 

[Sleeper]

LSMITH,

I'm not sure that a cam or ported heads would do much. Back (way back) in my SCCA days, we improved flow (cam/heads) to increase the volume of mixture into the cylinders. With 34 PSI, that's not really an issue. It would improve response but not fuel volume. My exhaust is clean, very little smoke, so I suspect my fuel/air mix is about right. Piers was keen to put in cam after my dowel pin killed the cover (whole nother story) but I couldn't't justify the expense if it didn't help my towing performance.

 

[LSMITH]

Sleeper, I don't think the gain will come in simply adding more air, but in adding a smoother flow of air. If the air can flow smoothly the same volume can get into the cylinder under less pressure, less pressure needed means your charge air temps can drop. Dropping charge air temps is VERY effective in fighting EGT.



At 34 PSI you are at the top end of the HX-35 and charge air temps might surprise you.



Also on the larger injectors, if you can get the same charge of fuel in the cylinder in a shorter period of time EGT in the manifold will drop. You might be able to install larger injectors and pull the fueling back a little for the same power with slightly lower EGT.

 

[illflem]

LS, could it be that lower 24 valve egts are due more to electronic defueling and timing change when high egts are encountered rather than the head design?

 

[LSMITH]

Bill, I don't know for sure but I would not think it that drastic of a change in timing between 12 and 24v engines, and the fuel has to be there to make the power. The timing is not a priority suspect of mine as lots of guys are trying17* and more of initial advance in the 12V and it is not curbing the EGT much, not to mention cylinder pressures get really high really fast leading me to believe that headgasket failures would be much more common on the 24V if timing advanced a good deal at RPM. We know for a fact that a stock 24V head will move air a lot more efficiently than a stock 12V head, so that was what I was looking at first. The cam would also play a large part in moving the air efficiently. DD has claimed some huge EGT decreases with ported heads and cams. Maybe it is a combination of both on the 12V?



There have been guys running over 30* of initial timing in a 12V with mega fueling and nuclear EGT but none that I know of at a more modest power level. I wonder if anyone that has a timing set would try a couple setups at the risk of the headgasket? Maybe 20, 25 and 30 degrees of advance? I seriously doubt a stock headgasket would live though beyond 20*. We know that 12 -17 don't cut it, and any lower would make it worse.



Just wondering out loud. Good discussion!!

 

[Sleeper]

LS, I can't disagree with you on the theory but I have my doubts on the values. It's been far too long since I studied flow dynamics to have firm facts for you. I'll just have to drop back to my dollar to Hp rationalization.



If you think 34 is high, you should have seen the pyro when we had it at 39 and the plate forward! It was exciting and scary at the same time. When towing, I spent more time looking at the gauges than I did at the road. However when running light, rowing through the box sure was fun.

 

[LSMITH]

Sleeper, I know full well what you mean, I have seen 44 PSI with a stock HX35 and the EGT that goes with that much fuel



There have been some values posted on here by members that have done the testing of charge air temps at various boost levels, as well as data on the efficiency map of the HX35. It surprised the heck out of me. You should be able to turn up some data with a search. Just more food for thought, I certainly am not sure what the answer is.

 

[Reddog1]

Originally posted by got smoke?

Just curious as to what some of you would advise for someone who tows only occasionally but usually very heavy.



I've written out 370's already and was looking at Bully Dog 300HP injectors but was told that it wouldn't do much for the truck? Now I understand from stock yes it would, but this is for information for me to put back for later. I'm looking into getting a clutch and #10 plate in the next month or so so these injectors will be on down the line.



Anyhow what are some suggestion on Injectors to help in the power dept. but keep the EGT's under wraps for occasional heavy towing? DDII's have been suggested but I cannot find a price for just injectors on their website.



Anyhow I'll shutup now because your opinion is what I want.

Thanks,

None of us has really responded to GOT SMOKE?'s thread.



I for one would agree that the 370's would not do what you want. I am considering stock or 215's.



Maybe someone could identify each of the most common injectors, performance to be expected and price range?





Wayne

 

[JohnE]

Try the first page, Wayne

<small><hr><blockquote>JohnE replied:&quot;...

Do the governor springs, AFC spring, and #10 plate. Evaluate where that got you which should be nearing 400 hp.

... &quot;</blockquote><hr></small>



The baseline here is already 215 injectors and the big pump and good timing. If Mark was starting with 160 or 180 injectors, then the order would change a bit.

 

[Reddog1]

John - Do you know from first hand knowledge that with governor springs, AFC spring, and #10 plate that you would have close to 400 HP? Has someone with that combo dynoed?



It looks more and more like I may have some 370's for sale in the near future.



What are our options on injectors?





Wayne

 

[J.R. Adkins]

IMO you should get the 370,s. When towing, just back out of the throttle. How fast do you plan on towing that heavy load? Or you can drop a gear. It all depends on you. How often do you tow? You don't have to tow at full power in 5th gear.

If you want to tow with a lot of power go to twins. JMO







J. R.

 

[JohnE]

A 96, 5 spd with a #11 plate and AFC spring did 345+hp.

Adding governor springs and a 16 cm&sup2; housing produced 360+hp. Piers suggested he go with a #10 plate next. A #10 plate is generally rated 50 hp over a #11 plate.



J. R. and LSmith offer another approach that probably is the better option IF you keep the engine rpm and vehicle speed down. Bigger injectors give more power through the entire rpm band.



Wayne, when you dynoed and run the high EGTs was it in direct (3rd) or OD (4th)? I've noticed some operators use 3rd and some use 4th on the autos.



What is the difference between a HX and HY turbo?



-John

 

[JJW_ND]

Time will tell???

No expert on timing but the shop several of us use up here sets most all at 20 degrees. Several dozen trucks setup this way. What I noticed over stock timing (maybe slightly above stock) was much less black smoke, much more crisp response (especially with a very cold engine), slight lower EGTs and 30 hp increase. The HP increase was a before and after timing change without leaving the dyno. After 100k of use and no headgasket problems I will be in a better position to speak of higher timing and headgaksets.



Timing on 12V is fixed. No change with RPMs. Not the case with 24V!



My experiece has been a #11 in a 215hp 5sp with 4" exhaust, BHAF can reach low to mid 300hp with out any EGT issues. Under 2700 rpms no matter the load would be under 1300. After I added GSK I could once again reach or exceed 1500. Higher RPMS and 12V means high EGTs. This is with a #11 which is a somewhat consverative plate.



Al at Piers recomend a more agressive plate over injectors when I asked a while back. You have adjustablity with a plate to increase or decrease EGTs. With injectors, they dump the same "extra" fuel all the time. This might pertain more the 215hp 5sps as they get much more response out of plates.



jjw

ND

 

[Reddog1]

J. R. Adkins - I have a slide-in camper that weights in at about 2600 lbs. I also have a 35-foot 5th wheel (12000 lbs. ), haven't towed it yet, but will soon.



On the camper, I played with different gears. I also have an auxiliary transmission set-up as an under drive (3. :54 or 4:10).



I do have the 370's. I guess I am having problem with having the HP, without being able to use it.





JohnE - I wonder how different 5 spd is compared to the auto? As verified HP, with those configurations, I am encouraged.



As for the bigger injectors giving more power through the entire rpm band, my dyno sheet supports that. I went from 1800 RPM to 2050 RPM shows 246 HP. At about 3150 RPM, it drops to about 220 HP. On speed, the chart shows 248. 6 HP from 46 MPH to about 75 MPH. I might add, the dyno guy would not go over 1200 degrees.



I think it was dynoed in 4th OD. It was in the 3:54 gear auxiliary Trans gear.



I have no idea as to the difference between a HX and HY turbo.





JJW-ND - The dyno numbers you have experienced are comparable to those of Johns.



I am not sure I am willing to go more than 16 degrees just yet.





Wayne

 

[J.R. Adkins]

If you want to use all of your power(well most of it ) get a set of twins.







J. R.