J02ws6transam

Hey guys. I have.m a 07 z06 that I just ordered a magnuson heartbeat system for. The car is a stock z06 with a set of ported heads from ahr to address the valve issue. Any other mods you guys suggest I do to the car while doing the install to keep everything happy with the car? Is a catch can a good idea? Will the factory balancer hold up ok? I am thinking about getting a racetronix fuel pump harness for the boost a pump system. Any help is appreciated.
Jon

CI GS

Definitely get the Racetronix harness. That’s the best value for money mod you can do on a C6, IMV, and it makes connecting the BAP a breeze, of you order the BAP connector kit along with it.
I would change the balancer too. The factory ones simply aren’t designed to drive a blower and tend to come apart after a while anyhow. I think oldmotorhead has a nice 10% Powerbond race series balancer for the dry sump motors that he wanted to sell. Hopefully he’ll chime in here soon. He’s our resident “TVS guru”. The Powerbond is a high quality option that cost quite a bit less than the high end IW and ATI dampers.
A catch can is definitely a good idea. Best one, hands down, is Mighty Mouse.
You’re gonna love that car. Your tires, not so much...

J02ws6transam

Thank you for the response. I will have to look at those balances. I will get the racetronix harness for sure. And probably a new balancer and catch can as well. I’ll be pinning the crank anyway so now is the time for the balancer. What is the difference between the regular balancer and a race balancer? Which would I want? Also would the 10% change the blower speed and my psi? Would I want to stay the same size?
Also when I drain the coolant for the engine I was thinking of just using some redline water wetter and distilled water. The car is not driven in the winter and gets stored in a heated garage that never gets below 55 degrees. Does any antifreeze need to be added for any lubriacting factors in the system or can I run straight distilled water and water wetter?
Thanks again.
Jon

TXSTICK

I will be installing a complete 3" ZR1 exhaust system on my LS3 with the heartbeat. It is suppose to work very well and allow the maggie to breather better.
ATI damper and pinning the crank next Tuesday.

CI GS

The difference between the Dayco/Powerbond race series dampers and a regular balancer is that the outer ring is held in place by a huge circlip, and the balancer is designed for greater durability in high-RPM/racing conditions.
The 10% overdrive will definitely change your blower speed and your boost, but I doubt that the boost would be too high for pump gas with the low boost upper/blower pulley that Magnuson ships with their blowers. More than likely, it will only bump your boost up from 5-6 psi to 7-8 psi, if I had to guess.
All I ever use as coolant in my vehicles is distilled water and water wetter, since our “winter” temps here only get down to 75*, so antifreeze is a waste of time for me. Been running that in my daily driven truck for over 9 years now, and haven’t had any issues.

old motorhead

How fast do you want to go? Find out what size blower pulley your kit ships with. Without meth, I wouldn't want to be over 9 or 10psi on an LS7. With standard crank pulley and 81mm blower pulley, you shouldn't be over 9psi on your set up. That would be a fun ride right there!

Unreal

Last I checked dayco/power bond don't make a dry sump balancer. Check out IW for a good blower balancer.

old motorhead

Don't know about now, but they did a year or so ago. I recently sold a 10% O/D one that would fit LS7 and dry sump LS3. https://www.coloradospeed.com/pulley...bp01p7fqcdsjt3

Unreal

Good deal. Never mind then. There was a few of the cheaper balancer options that use to be only wet sump.

Then again CO speed is about the worst vendor around, so please don't buy it there.

old motorhead

They aren't my first choice either. When I looked, they were the only place I could find it. May be different now.

CI GS

Here it is, as listed on Summit’s website:
https://www.summitracing.com/dom/parts/pbb-pbo81503sc10

Not much detail on there as to what application it’s for, but if you go on Dayco’s website and do a search for a 2010 Corvette with the 7.0L, that’s one of the balances listed, so that must be the right one:

J02ws6transam

I have dont a few list searches for the ls7 for the dayco and they do offer the premium and race version for both standard size and 10%. Thanks for all the help guys. One other question i am trying to figure out but have not been able to get a good response on... magnuson says the system for a totally stock ls7 produces 5.5 pounds of boost. I am stock except for having ported heads. I know the ported heads will decrease my boost a little with the extra flow, but will it lower it enough that i should try to compensate with a 10% overdrive or smaller pulley on the heartbeat? I wont be racing the car so im not looking to get every bit of power out of the motor, i would rather a safe reliable motor for cruising and tire smoking but also dont want to leave too much extra power out there either. The car will be tunes once its all said and done anyway, not sure by who yet, still figuring that out, but just trying to get this all figured out before the install.
Thanks for the help
Jon

Unreal

Boost doesn't matter for reliability. Your pistons/cylinder walls don't care about boost, they care about cylinder pressure. If you make 1000psi of cylinder pressure on 3psi of boost or 5psi of boost, it doesn't matter.

CI GS

I agree with Unreal, but 5.5 psi of boost with a stock cam is not much, even for an LS7, so putting a 10% OD balancer on there with the standard Magnuson pulley should still be safe, as long as the tune is done properly, and especially so if the ported heads drops your boost down by, say, another .5 -1?? psi. The 10% OD would be roughly the equivalent of dropping down one pulley size (-3mm, from 96mm to 93mm) which typically gains roughly 1.5 psi on a stock cam LS3, and probably a little less on an LS7.

By way of demonstration: a 10% OD, which has a ~ 8" (209mm) diameter, combined with a standard 96mm pulley, works out at 2.17:1 in terms of pulley ratio, and the stock balancer, which has a ~7.5" (191mm) diameter combined with a 93mm pulley (one step down in size from 96mm) would equate to a 2.05:1 pulley ratio. So its pretty much a wash, with the 10% OD balancer and 96mm pulley being able to make a very slight amount more boost than the stock balancer and the 93mm.

If I had to guess, I would say that you would end up with somewhere between 6.5 and 7.5 psi, which should be safe, with the right fueling and timing.

schpenxel

Insta-ban coming up

Unreal

Think of it this way, the HB 2.3 L blower is spinning at 25k RPM and on a 7.0L LS7 that has a fairly big cam, big flowing heads, lots of cubes you see 5psi, make 650rwhp. Put that same blower, same speed on a 6.2L LS3, smaller cam, lower flowing heads, etc now you have 12psi. Because the one motor is more restrictive, but they make the same power, blower working just as hard and spinning same speed. Both make ~650rwhp. Cylinder pressure is near identical. So don't get caught up on PSI. LS7 seem to stay reliable in the <700rwhp range, assuming you have nothing but great gas. It doesn't matter if it takes 4psi or 10psi to get to 700rwhp, just keep it in the safe power range, not safe boost range.

J02ws6transam

Thanks guys for the great explanations. Luckily i do have 93 octane fuel in new york so that does help. It all makes alot of sense. I never really thought if it that way about cylinder pressure vs boost. According to magnuson and there dyno charts the tune that comes with the kit at 5.5 psi puts 585 hp to the wheels and im sure thats very conservative for them to keep things safe. So if I get the 10% overdrive balancer and get 1 psi more give or take, i will still be well under 700 hp to the wheels and should be fine. I really appreciate your knowledge guys and taking the time to help
Jon

CI GS

I get it that cylinder pressure is the major determinant of the onset of detonation with any given fuel, and that a particular blower produces different boost on different engines, etc. But, on any given engine, boost is also a factor in the onset detonation as well, since increasing boost on any engine will raise both IATs and cylinder pressure. And we're dealing with and comparing known baselines and rotor speeds and can predict boost, based on the number of examples of both LS7s and LS3 out there with stock cams and this particular blower.
The problem (at least for me) is that there's no way to easily determine cylinder pressure, other than looking at RWHP, which varies from dyno to dyno anyhow. And, you could easily have a situation where one engine can make 700whp on a specific dyno, with a certain AFR and ignition lead, and another make an identical whp number with less fuel and more lead and the latter grenades itself in minutes on the dyno and the other lives for 100,000 miles...
So, whilst I agree that it's cylinder pressure, particularly, violent spikes in cylinder pressure caused by detonation, that is the durability-limiting factor of any engine, given that we have a decent idea of output based on calculable rotor speeds and boost on a stock cam LS7, it's simply easier and just as safe to opine on what is a safe boost level on that combination of engine and blower as it is to say what is a safe RWHP level. I'm not trying to provoke argument on this, but rather trying to explain my thought process, FWIW.

Unreal

True, if you are talking stock motors, but once you throw in headers, heads, cams, etc etc then it all goes out the window.

old motorhead

I realize how cylinder pressure plays in to power. CR, valve timing, ignition timing, altitude, temperature, load, boost, etc all need to be accounted for. I have no point of reference there though. I do, however, know how fast a TVS 2300 blower needs to be spun to make X amount of power on an LS platform. Sure, there are differences due to intake and exhaust variances. Cubic inches also will change things. I think, based on my experience with three different TVS2300 blowers, that a Heartbeat running an 81mm top pulley and stock diameter crank pulley will net the OP 650-700 rwhp. And boost should be considerably less than 9psi. I mentioned boost to bring IAT's into view. With less boost, you have lower IAT's. Lower IAT's yield more power. Also, less boost gets you less load on the blower drive system. Much less likely to be dealing with any belt slip issues. Don't want another guy on here dealing with "Sammy" issues.....