metal_miner

About 2 months ago I "downgraded" to a SPS 62 turbo from a SPS 66 for resons I explained in post #18 of this thread.

Well, I finally dynoed the SPS 62 turbo today with the 3-flow (100 HP) injectors + TST PMCR (twins program)+ PDR cam combo. These were the UNCORRECTED results:

0x0 362 HP / 663 TQ
1x0 388 HP / 723 TQ
2x1 428 HP / 911 TQ
3x1 466 HP / 999 TQ
4x1 522 HP / 1061 TQ
5x1 431 HP / 872 TQ
2x2 480 HP / 1049 TQ
3x2 502 HP / 1066 TQ
4x2 539 HP / 1000 TQ

Cleary above level 5 I lost power due to the rail running dry causing poor atomization, high EGT, and tons of smoke. However, it was also interesting to note that the EGT on the dyno didn't utterly peg the gauge until I selected Level 4. Dyno EGT were pretty tolerable up to the 460 to 480 HP level. I would suspect during real-world driving, the EGT might be higher at these same power levels due to higher engine loading. Ahhh, if I only had twins...

I also didn't test higher than Te level 2 since I pretty much knew I would lose power and drain the rail even faster due to the stronger low end fueling based on other people's posted dyno experiences.

I did have a TS MP-8 pressure box, but didn't hook it up as I felt that I wouldn't gain anything more of significance. I was also 4.5 hours from home so I didn't want to chance blowing anything up ... Anyway, without the MP-8 my rail pressure still pegged the max on the rail pressure gauge (26,700 psi) due to the ECM trying to feed the injectors.

The graphs of power versus time also show that as expected the SPS 62 spools faster than the SPS 66, resulting in earlier power and torque. This is much better for towing and stoplight-to-stoplight! For instance, the graphs I have collected show the SPS 62 going from 100 to 350 HP 0.1 to 0.2 seconds faster thans the SPS 66.

BTW I also had a chance to briefly meet up with DTR member cquestad. Good guy with lots of very helpful truck tuning knowledge and the pictures in his gallery don't do his truck any justice! Next time through I hope to get some more time to shoot the breeze as unfortunately our schedules didn't mesh.

Anyway, here's some graphs, with the last graph comparing the SPS 66 to the SPS 62 power delivery. The 62 comes "on" 100-200 rpm lower than the 66.

realsquash

So the rail went way high, eh? No pressure box? Was it high the whole time or just at a certain RPM? What's up with the dip at 2000 rpm? It's present in all the graphs.

Thanks for posting that data, very interesting!

Andy

PourinDiesel

Nice numbers!!

Very impressive. Looks like you really tuned it perfectly!

metal_miner

Andy-

Very good eyes you got! Correct - no pressure box. I have a theory that with big injectors the ECM would up the fuel pressure due to shorter duration to output the same amount of fuel as a stock type injector under similar circumstances. This in effect is the same thing has advancing the injection timing. When I ran a MP-8 stacked with his TST you could hear his happening under normal conditions so I didn't want to have things happening too aggressively with 2 aggressive boxes! I felt that this would make the power really peaky too.

The rail pressure looked to spike on the gauge in the 2000-2500 rpm range and then it is all downhill from there.

As far as that 2000 rpm blip I have noticed that in practically every TST dyno posted. Some are not at 2000 rpm and could be at 2100 rpm. I guess that depends on the truck. Weird ju-ju going on!

realsquash

I was just looking at the graphs again... It looks like the Juice doesn't have the dip, but it's almost as though it intentionally avoids ramping up around that area. Maybe it's just coincidence. The 0x0 also doesn't show the dip, and at 2000rpm has more torque than 3x2.

Something is up with these engines and 1900-2100 rpm. If I drive my truck in that range I will always get 21mpg. Any higher and it drops off fast. At 2300rpm mileage is already down to 18, 2500rpm and it's 16. Very odd... I have felt a flat spot there with just my EZ installed. With the Tripledog only I don't feel a dead spot there. Both stacked and there's no discernable dead spot so that leads me to believe it's programmed that way. But what gets pulled back? Timing? Duration? Pressure?

I wonder if there's a dyno graph out there of a BDDL stacked with a TST. Or even just a BDDL. Or a TST on a 4.5+. I am going to do a little digging for that now.

Andy

metal_miner

I have lots of SPS 66 and HTB2 62/14 dyno graphs I can post with the Edge Juice with 100 HP injectors or I can email them to you if you want.

What I found with the Edge stuff is that the power and torque curves really, smoothly follow the factory curves, but at a higher level of course. The TST curves seem to be more peaky / "violent" - and I don't know if that is a function of running out of rail pressure or not.

As for TST / BDDL stacks, PourinDiesel above dynoed with that combo so he might have some graphs to share!

realsquash

Post or email is fine with me (realsquash at gmail dot com), thanks a lot! I wonder what a VA 3.2 does... I just wonder too much, that's my problem!

Andy

CG98x

Seat of the pants tells me the 3.2 has the same dip, whether it's stacked or by itself.

metal_miner

Realsquash-

Dyno with Juice and HTB2 62/14 + DD3 injectors + PDR cam:



Dyno with Juice and SPS 66 + 3-flow injectors + PDR cam:



Dyno comparing HTB2 62/14 turbo to the bigger SPS 66 turbo:

realsquash

The first Juice graph shows more HP and TQ under 2000rpm turned off than when on. That is so very odd to me. There is still something going on at 2000 there but the Juice seems to skirt around it.

EDIT: it looks like at 1900rpm or so the Juice on 0 is a full 100lb-ft ahead. What the ???

I've read that the 555 Juice uses pressure were as the 600+ doesn't. There's no Crazy Larry for the 555, but apparently they did testing with one and it wasn't driveable. What does it all mean?

Next time you do a dyno run you should try without the VSS hooked up on the tranny and see what happens.

Andy