J02ws6transam

Soo much information to process. And I do appreciate it. I am really glad I asked this question because with the ported heads I was going to leave get a factory size powerbond replacement balancer and stick with the factory pulley which I think would just leave too much power on the table. I think going with the 10% overdrive factory heartbeat pulley and a good tune is the way to go. I will be having it tuned at rpm in Delaware so I am confident they will do a great tune.
Lets hope for the best! Thanks again guys
Jon

old motorhead

Let us know what size blower pulley your kit comes with. You're probably still leaving a lot on the table, even with a 10% O/D crank pulley.

J02ws6transam

By the sounds of what everyone says and what Info j can find it looks like it comes with a 96 mm pulley. Would that be playing it too safe and leaving too much on the table?

old motorhead

Yeah, that would be playing it too safe in my book. With a 10% o/d crank pulley and 90mm blower pulley, you still should be plenty safe. That's the equivalent blower speed of the stock balancer/81mm drive setup that I mentioned earlier. You can easily go up from there. Changing a blower pulley is a five minute job.

Just beware that you may need a tune touchup if you spin the blower faster that what it was tuned for. One of mine threw a "lean bank one" code at cruise after speeding the blower up very slightly. I was on a 500 mile trip when the code came up. Cleared it several times, but it would always pop back up. Just stayed out of boost for the entire trip (bummer) and got it tuned when we got home. Despite what you read here, you can actually accelerate quite briskly without ever getting into boost.

J02ws6transam

Thanks for the info. Which size I decide to go with I would figure out and have set before I take it and have it tuned. Now I have some thinking to do about sizes do go with. I want to be safe but not overly safe lol

CI GS

I don’t know whether I can agree that a 10% OD (209mm) balancer combined with a 90mm, which works out to a 2.3:1 ratio is going to be safe on a LS7 with just 93 octane. I just don’t know, is all I’m saying...
But I can say with certainty that a 2.1:1 ratio - which is what you get if you combine either a stock 191mm balancer with a 90mm pulley or a 209mm (10%OD) with a 96mm pulley - is safe on a stock cammed LS3 with 1.75” headers. I can say this because I ran that combo for about a year on my car, with the stock cam, with 14 degrees of timing and a ~11.6:1 AFR, with nothing other than 93 octane pump gas, and the car ran flawlessly like that, making around 8.5 psi of boost. Sometimes I wish I had left it alone like that, to be honest, lol.
But there is something else the OP needs to keep in mind, and that is injector capacity. I don’t know what the LS7 kits come with, but if it’s the same LS9 injectors that comes with the LS3 kit (as I suspect is the case), then given that he will be fueling a bigger motor, making more power, he will most likely run out of injector, even at a 2.1:1 pulley ratio. My car, with the aforementioned combo, was maxing at 93% IDC with the LS9 injectors, so I’m sure with the same pulley ratio, he will be beyond 100% IDC with those same injectors.
So, I would talk to Magnuson and see which injectors they sell with the kit. Personally, if they’re the LS9 injectors, I would see if I could order the kit without them and get a discount, and then buy some ID1050X injectors, because then you have more injector than you would need, probably even with E85. The ID injectors, combined with the data they give you for them, are amazing. I would bet that easily pay for themselves with the better/more accurate fueling they give you.

@Rodney: I think we should leave this guy alone now, and make him figure out what to do. Because you’re a bad influence, as we all know already, and I’m worse, so the poor guy basically has one devil sitting on each shoulder here...

J02ws6transam

The kit does come with ls9 injectors. I don’t want to push the car too hard. I would rather be safe than sorry. I will just go with the 10% overdrive balancer and standard pulley on the blower and get it tuned. Then hopefully with the ported heads it will even out or just be slightly higher like you said and I won’t have to worry. I really do appreciate all the help and info everyone has given me.
I can’t wait for the install. Also just ordered the Mighty Mouse wild kit to install at the same time. I will Ofer the 10% overdrive balancer today that way my mind is made up lol.
Thanks again
Jon

Turbo6TA

BTW ... The 'LS9' injectors that come with the Heartbeat kit are actually Bosch P/N: 0280158187 .... rated at 52 Lb / Hr @ 58 PSI

old motorhead

So yeah, the injectors that come with the standard kit are too small. I thought that was a given. That's no big deal as, because of the smaller pulley, and ported heads, he'll need a custom tune anyway. OP needs to order a "tuner" kit that comes sans injectors and tune. Save a few bucks there as he'll need to buy both a tune and bigger injectors. Sky's the limit on which injectors to buy. He could get along just fine with 60#'s if he's going to keep the power on the mild side. I think mine were at 75% at 640 rwhp. A little more upside with the 85# injectors. They're fine until you all flex fuel into the mix. Then, you need to upgrade to 110+. Ahhh, decisions and more decisions.

Still don't think the 90mm and O/D pulley would be too much. If it were mine, I'd probably go with the 87mm pulley. I haven't blown up any LS motors yet due to making too much power. With a good tune and consistent octane, they hold together pretty well.

J02ws6transam

So are you saying the injectors that come with the kit will be too small for the factory blower pulley and 10% overdrive balancer?

old motorhead

That's probably OK, but have your tuner watch it closely.

Turbo6TA

When I purchased the "Tuner" kit, it came with the Bosch injectors I mentioned above.

But they did take $200 off the price of the kit since I didn't get the hand-held tuner with the canned tune.

J02ws6transam

When I was buying the kit, I wasn’t even offered a tuner kit. I was only offered the complete kit. And unfortunately rpm where my tune will done is a 3 hours drive away so I wouldn’t have needed a basic tune to get me down there anyway. I’ll just keep out of boost for the drive down. Will be so hard not to mash the throttle lol

Turbo6TA

Just to let you know ... Even if you are getting the car dyno tuned, you will still need to install the canned tune in order to drive it to the dyno for dyno tuning ... It won't run without some kind of a tune since you will have the LS9 MAP sensor installed.

Only other way that it will run (if the canned tune is not installed, and it has not been dyno tuned) is to install the LS3 or LS7 Map sensor .... then drive the car to the dyno and re-install the LS9 MAP sensor once the car is on the dyno.

J02ws6transam

Yes I will install the canned tune for sure. That way I can drive it around a bit before I take the car to get tuned to put a few heat cycles in and make sure everything is ok.

old motorhead

Magnuson changes these kits up sometimes. My HB tuner kit came without injectors and tune. My first jackshaft TVS came with a Calloway Honker CAI. They changed that up also after the first few units were shipped.

J02ws6transam

I was looking at the powerbond balancers this morning and for the ls7 they actually make a 10% overdrive made for supercharging. It has a SC in the part number and in the description states it’s made to increase boost (which obviously it would) without having to decrease pulley size on the blower. I just thought that was interesting. That is the balancer I will wind up going with.
Jon

CI GS

Isn’t it the same one I posted the picture of and the link to on Summit and oldmotorhead referred to in earlier posts on this thread? That should be the 10%OD 8-rib supercharged version, for the LS7/dry sump LS3 motors.

J02ws6transam

Yes. It is the same balancer. Sorry I overlooked that when I wrote that post. I just thought it was interesting they made one to work for supercharged motors. Very cool. My mistake
Jon

old motorhead

Send RPM a message and get their thoughts about your pulley selection. They may have done a few of the LS7 Heartbeats