Hello, Tech - for those unfamiliar with my build, the link is in the signature. I posted here, because it's relevant to the dyno section, but also in my build thread in order to keep everything together.

To cut right to the chase, I got new numbers and I'm super stoked!

510@6500 and 448@5500. This was done on a different dyno in order to dial in some low rpm and part throttle stuff I was struggling with on the street. I'll go back to the other dyno to get a more direct comparison on the previous dyno I ran on after all the current testing (and tuning) is complete. Regarding the different dyno's, I asked the operator how his dyno compared to the other one I previously tested on and he said they were typically within a percent of one another and that on any given day, one might be 2-3 HP higher or lower than the other. Guess we will see when the smoke clears. Overall, he was very impressed with the quality and attention to detail of my build, especially compared to the POS hot rods he typically sees where people think they can dump $300 into a car and get 400 HP. He blames hot rod magazines for that, which I thought was pretty funny.

So the dyno operator is extremely ADD and he likes to be left alone while tuning and doing pulls, so I was relegated to a waiting area while he tuned. After the first pull he immediately enters the waiting area where I'm anxiously sitting and asks me to confirm the displacement of the engine. I tell him once again its a 346 and he seems very surprised sharing with me the first run/baseline was already 501/441 (which was close to where I was hoping it would be!), and then he shares with me the previous best 346 on his dyno NA was 470. So, he continues to work the tune over the next few hours, and we end up at final figures of 510/448 which is obviously awesome! Even some other guys in the shop and office came up and asked about the build during all this, so word had already spread. When it's done, the first thing he says to me is "You must have the best cylinder heads on the planet! I've never seen anything like this, and if I hadn't ran the dyno myself I would be calling BS".

Afterwards, we chatted for a while, and we started talking some of the behavior on the dyno. First, it ended up making the best power at 23 degrees timing, which just floored me, but it was true. At 26 degrees, it didn't knock, but it pulled 501-504 on consecutive pulls. I wish we had 93 instead of 91, because a bit more timing and a bit better fuel might have come in even higher. He said that the 5500 peak torque suggests very strongly that this thing wants to make peak power higher. But during the pull, you can hear the tone change around 6300 (video attached so you can hear it plain as day), and that change carries to 7K, where he stopped the pull, because it wasn't making more power. And you can see on the attached graph, that it just flatlines at 6300-7K as well. So, he tells me the intake is holding the motor back, to which I started laughing. I told him I just had a hard time thinking of a Mamo ported fast 102 holding an LS1 back. He then says, he's in uncharted territory with this motor as well, since it beat the previous best on his dyno by 40 HP!. He says that it feels almost like some weird harmonics in the intake where the heads are trying to draw in more air and it's just not available. He then says, he thinks the engine needs a bigger plenum intake with shorter runners. Which points straight to the MSD airforce. Or sheet metal, which I don't want. I discussed this with Tony Mamo later that day and we had (in the past), already batted around the idea of trying one of his ported MSD's on my motor knowing going in we are going to trade low/midrange torque for upper RPM power, based on some of the other testing Tony has done. I REALLY want to see what the full horsepower potential of this combination is so I have already given Tony a deposit to get one of his ported MSD intakes in the works which should be an awesome test - and back to back with no other mods. If the MSD does what I HOPE it does, I'll use the fast for a truck build up in my suburban.

Comparing this run to the previous run at 496, there are some interesting changes, which do point to potentially reaching the ceiling of the fast 102 at the high end - not entirely sure on this, since bigger cube motors do fine on it, but it may be RPM related. Here is sort of a chart to try to help summarize the differences between the pull:

HP............................496................. ..............510
RPM........................6800................... .........6500 (indicates intake potentially not keeping up)
TQ............................431................. ..............448
RPM........................5100................... ..........5500 (indicates power band shifted higher in RPM)
Cam.....................hydraulic................. ........solid
Duration...............227/235......................232/240 (hydraulic equivalent)
LSA/Adv................112+3.......................... 112.5+2
Rear Axle..............stock........................... ..fabbed 9"
Gear.......................3.42................... ...........4.11

As I understand it, when you increase gear, you "consume" HP to gain torque. Add to that the weight of the rotating parts of the rear, and I figure there must have been at least 20 HP in driveline losses due to the upgrades that were made in response to all that DAMAGE. I blame Mamo torque! I did what I could to minimize those losses, but it needed the heavier hardware, and the car has responded quite well to the gear, enabling me to run 28" tires - to which the car has also responded quite well.

So, next steps: I'm going to try a Mamo ported MSD. Based on the torque peaking higher and the HP peaking lower, I do agree that the shorter runners of the MSD will help the top end of the combination carry power better. We'll do the swap and go back to the same dyno for a direct comparison between the two intakes, which will be the first test of Tony's ported cathedral MSD on a 346 cube engine. Once that is done, I'll go back to the dyno I pulled the 496 on many months ago for a direct comparison of before and after. I also need more injector. The 39 pound deatshworks are at 92% duty cycle. I have a set of 42 pound FIC that will go on. These have the EV14 spray pattern, which will do much better at lower flow vs the stream of **** the deatshworks make, but I will change the injectors after the intake swap to eliminate any variables that could affect the intake manifold test

At this point, I feel we could be close to finding out how much can truly be done with a street 346 with some of the best parts on the market currently available!

 

Nicely done sir!

 

In for MSD results, for sure. Great job.

 

Signing onto the thread. Those are indeed fantastic numbers.

 

The correct combination of parts and systems, attention to the details on the build, on parasitic losses, accessory efficiency...well done and the numbers show it. This is brutally f*cking awesome!

 

Very nice! Interested on how the intake swap helps. What's the details on the engine , what heads ,or is this all top secret? Awesome Numbers!

 

No secrets here Darth has EVERYTHING in his build thread,
Referenced in his first Sentence!

 

Thanks ZZ! It's a LONG list. I put the build list link in my sig to make it easier. I'm expecting the swap to cut torque back a smidge and move the HP peak about 500 rpm higher, but that's an educated guess at best based on the LSD vs fast stuff on the LS7's.

I'm hoping to have the swap numbers rather quickly. it won't take long to swap it, and for a quick baseline pull, shouldn't be too much effort required. if it looks like it's trying to pull harder, I'll burn the "baseline" session for a tuning session. If it looks no different, then I'll just take the baseline run and go.

 

That's officially the best compliment the car has ever received!

 

Very well said!!!

 

Cool deal. I'll check out your build thread and look out for the intake results. Kinda wondering if I could benefit from the intake swap as well.

 

That's ******* sick, congrats!

 

Well done my man. I bet you are super stoked.

 

I think you will. I don't know your build that well, but if the avatar pic is an indication of your car, I'm thinking the shorter runners will extend the RPM a bit higher, and should carry better past peak. I'm expecting to see torque drop back into the 430's and the HP peak up closer to 7000 RPM, which would be about right with a 5500 RPM peak TQ. We will see!

Thanks guys! I am quite stoked (my poor wife on friday...)

 

So the way I understand it, it was 496 with the 10 bolt and 3.42's and now 510 through a 4:10 9"?

 

Yes, that's right.

 

The shirt Mrs DarthV8r is wearing in his signature might be a clue.....LOL (MMS 220 heads!)

Just wanted to throw my hat in the ring here and also extend Jacob a big congrats on the results. He is another guy that has sweat all the details of his build. This guy invests a tremendous amount of time thinking about and wrenching on his car and the results are the sweet victory of that effort (for the folks who may have missed his detailed beyond detailed build thread be sure to check it out).

And not to mention he is a genuine good guy who helps out the community as well with all the info he freely shares

Regarding the manifold test I expect the results to mirror the test I conducted awhile back on the engine dyno with a 416.....basically giving up a good bit of lower/midrange torque for an inprovement in peak power and the engines ability to hang onto it.

The car may even fell a tad slower driving around town but assuming the top of the curve does come around (like my 416 example), and your willing to sidestep the clutch around 5500 and shift in the 73-7400 range, the car will be brutally fast keeping the RPM up there in it's new "sweet spot" (It will be a more "peaky" power curve with this manifold choice)

Should make for a wicked sounding in car video.....hint hint......LOL

Here is a very informative thread I posted a ways back about my ported MSD vs my ported FAST.....read it if you haven't seen it as this intake isn't for everyone....you need a well thought out and optimal valvetrain (with perfect valve control), especially in a 346 which will want and need to rev high to take full advantage of its attributes.

https://ls1tech.com/forums/generatio...orted-msd.html



Cheers,
Tony

 

Never realized the sig pic was *****. Nice!

Again, great job guys(& girls). Top notch combo not even at its peak. Yet!

 

I like *****

 

Awesome numbers!