Custom 12mm VE coming soon!

Here's the dyno sheet. The 2nd run was actually the highest at 249hp. The 1st run, the one JQ got on video, was 248hp.
 

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Why did it drop off so bad on the first run?

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jimbo486 said:
I'm on-board with Jason and others agreeing that it needs more fuel. 1200degs. is very low. I didn't pay attention to that gauge during the first run to even see where they were and didn't notice it until the 2nd or 3rd run. This pump makes 263cc's (max) at 2,000RPM engine speed. That's around 450hp worth of fuel. It drops a bit after that going to 233cc's at 3,000RPM and 220cc's at 3,500RPM.
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Your AFC might be too tight then.
 
Here's an old post KTA made on 1stgen.org.....testing different injector sizes versus cc. 4x14s versus 6x18s, the big sticks picked up nearly 80cc at peak. Just something to chew on.

To illustrate the effect injectors have and to show the potential power diffrences I ran the same pump set the same way through my 6x.018" and a set of POD's I have laying around. These are the results
RPM 6x.018 POD
1500 285 210
2000 300 210
2200 302 220
2500 277 180
2600 206 130
3000 45 35
 
chevota84 said:
Why did it drop off so bad on the first run?

Sent from my SCH-I535 using Xparent Blue Tapatalk 2
Click to expand...

I sandbagged. Wasn't watching the tach and looked as soon as I let out and wanted to push it more. Power was already dropping by then anyhow.

JQmile said:
Here's an old post KTA made on 1stgen.org.....testing different injector sizes versus cc. 4x14s versus 6x18s, the big sticks picked up nearly 80cc at peak. Just something to chew on.

To illustrate the effect injectors have and to show the potential power diffrences I ran the same pump set the same way through my 6x.018" and a set of POD's I have laying around. These are the results
RPM 6x.018 POD
1500 285 210
2000 300 210
2200 302 220
2500 277 180
2600 206 130
3000 45 35
Click to expand...

I can believe that. Looking forward to trying the 68lpm DDPs. Wish I could find and get on a local dyno to see what the improvement is. Giles' bench uses p-pump injectors for testing which I understand to be slightly smaller than stock i/c injectors, if not, the same size. It'd be interesting to see what cc's I'm getting with these 5x.012s for comparison.
 
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It's been my experience that with the VE flowing most at lower engine rpms, pretty-much riding the brake and letting the turbo(s) come online as you begin the dyno run helps a lot. (You're doing the same thing building boost prior to launching at the track).

But I agree with the others, you're not smoking enough at the bottom (short on fuel). That video and the dyno-graph suggests to me that the turbo was way late coming online. The VE's output was rolling off when the turbo got ginnin.

More fuel and earlier air, with a couple of hours on a dyno to dial in the timing should get you on up there.
 
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You can also come up to Irwindale when you get your bigger injectors in, and run the 1/8th mile and do the trap speed thing. It's usually been accurate to about 20hp for me, as long as you get the weight of your truck right.

Edit: And it's only 1/8th mile, so you don't have to worry about shifting much, or blowing up.
 
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BC847 said:
It's been my experience that with the VE flowing most at lower engine rpms, pretty-much riding the brake and letting the turbo(s) come online as you begin the dyno run helps a lot. (You're doing the same thing building boost prior to launching at the track).

But I agree with the others, you're not smoking enough at the bottom (short on fuel). That video and the dyno-graph suggests to me that the turbo was way late coming online. The VE's output was rolling off when the turbo got ginnin.

More fuel and earlier air, with a couple of hours on a dyno to dial in the timing should get you on up there.
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I think a big part of it is that this particular DynoJet is an inertia dyno. Those with experience with a Giles pump can attest that even with the AFC as tight as it is, it fuels harder on a load-type dyno. Compared to an inertia dyno that can't even load the engine as much as simply driving it on the street. And I can say though that it seems to smoke more on the street when I'm heavy into the throttle.

However, I wasn't aware that some braking could have been applied to the rollers to simulate a load until after I had completed my 3 runs. Had I know, that would probably have started some air moving sooner and thus, yielded better numbers.

Talking to my buddy with the mild 12mm from Giles earlier this evening made me feel quite a bit better. We both agreed that there's a chance that the static timing just might be too advanced. If Giles set it to 1.3mm, that's not much more than stock at 1.25mm = approx. 12.5degs. The extra rattle I can hear probably shouldn't be audible with a .05mm advance. The pump is almost touching the head and the pump gear wasn't jumped a tooth. Maybe that's where the 1.3mm positioned the pump? As I said in previous posts, everything lined up while locked at TDC #1.

I really should to get on a load-type dyno to see a more accurate number and check the timing.
 
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Superior Automotive I believe has a load.dyno. We had a Socal Diesel dyno day there a few years ago. It's right by Greg's house on La Palma and Magnolia. Or you can drive out to Westech.

Garrett

encrypted with an enigma machine
 
Brake boosting helpes out a lot on the dyno. My truck probably would have pigged out if I didn't ride the brakes as much as I did. I was a little upset for you when I read some of the earlier posts that you lost power. I was rooting for yah!! I'd try adjusting the afc so the fuel came on a little sooner. If it doesn't work you could always go back. Hope you get this figured out.

Eric
 
Sutter1stgen said:
Brake boosting helpes out a lot on the dyno. My truck probably would have pigged out if I didn't ride the brakes as much as I did. I was a little upset for you when I read some of the earlier posts that you lost power. I was rooting for yah!! I'd try adjusting the afc so the fuel came on a little sooner. If it doesn't work you could always go back. Hope you get this figured out.

Eric
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You need to re-dyno yours with those 6x16s, to see what you picked up!
 
JQmile said:
You need to re-dyno yours with those 6x16s, to see what you picked up!
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I know! I've been really busy. I'm in the process of going to work for my dad on his farm. A d right now I'm trying to get my current boss caught up with all of his planting and harvest equipment servicing. I'm going to try to sneak up to ponci's for the dyno at least. Which day is the dyno on? I'm real curiouse to see what they put down. And I promised you a re-dyno. Lol

Eric
 
Sutter1stgen said:
I'm real curious to see what they put down.

Eric
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I gained 50hp on my 95 160hp p-pump by switching from 5x12s to 5x18s, even without any additional timing. I'd expect you to see the same or even better with the amount of air you have.
 
A lot of the big hp fuel only guys run a lot of timing....I think some even have two teeth skipped!

Edit:"Big HP" being relative to the VE guys of course....LOL
 
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Spoke with Giles today. He was just as stumped as I am. A few things he suggested were to check the steel tube to AFC for leaks, verify the throttle reaches the high idle screw with the pedal to the floor and to try and watch fuel pressure while driving to ensure it's not dropping instantly for some strange reason.

The linkage reaches the high idle screw, check. AFC line isn't broken or kinked, check. I drove with it disconnected and was only seeing 15psi with my foot in it a little. It still felt somewhat strong but sluggish at the same time. I didn't give it a lot of throttle since it wasn't quite up to normal operating temperature.

Talking with him some more, he told me that the AFC starts full fueling at 25psi for a gradual increase. I verified that the static timing is set at 1.3mm and dynamic reaches nearly 10mm! I asked him about the position of the pump and how close it is to the head and wondered if it needs to be retarded a bit. He doesn't feel that that small of a chance would make a difference. He agreed that fuel feed pressure could cause the dynamic timing to advance too soon but again, not a big difference. Inlet pressure at idle is 26-28psi. With the engine off, the gauge shows 24psi. I'm thinking of backing the pressure down to around 20psi.

Trying to start with the small, simple things. Probably something so ridiculously small that I would never think of. Anybody have any more ideas??
 
Sutter1stgen said:
330/660 at johns BBQ. I may need to jump a tooth to help break that magic 400!
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Eric.
You ought to take a drive up this way and see the first gen for sale in Oregon House. First driveway past the post office. Worth the trip. Or stop here and we can drive up in my truck.

RonA
 
So what about boost referance for fuel pressure, start mid teens and ramp up? Just a thought. Good luck and hope you can dial it in.
 
Sutter1stgen said:
I'm going to try to sneak up to ponci's for the dyno at least. Which day is the dyno on? I'm real curiouse to see what they put down. And I promised you a re-dyno. Lol

Eric
Click to expand...

The dyno is on Sunday if you can sneak up here. It would be nice to meet you.

Stomp
 
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