Probably I asked few questions in different threads, however as it is getting more serious, just want to start a new one hoping all materialize.

LS3, A6, Cam kit, air intake and full exhaust are installed.
Last pull was 442 rwhp.

Aim is around 630rwhp. I have stock bottom end, and do not want to go higher, just to save the engine. Hope this is not too much for stock bottom end.

I plan to install KB BAP. Should I go 17.5 or 20 V.?

Plan for alky methanol kit. Should I go single or double nozzle?

What boost (pulley size) is needed to reach my goal?

Do I need 8 rips?

Do I need to change injectors size?

Magnuson website shows a need for hood liner removal or getting spacer from Lingenfelter. Which one is better?

Thanks.

 

I just went thru this whole process. If you go A&A, I would say go with V2 headunit, 3.6 pulley, kb bap comes with the kit, not sure about voltage, single nozzle meth kit, 6rib will do the trick. Trick is in the tune. If you have an auto expect to lose some 40hp in the process. I went with the V3 headunit and before too soon I will be reaching the max revs for this model.

Even with my percieved low numbers, my car now makes 200whp more on a stock engine with A6, not complaining....

 

Centris are good but do not meet my needs. I made up my mind. It is a Magnuson Heartbeat.

 

All u need is a few threads down.


https://www.corvetteforum.com/forums...o-numbers.html

 

Hey ... have the Heartbeat on my 08 - Auto ... cammed - at 10PSI dyno at 631 rwhp - 575 rwtq... car pulls hard ...
Installed valve springs - upgraded injectors - Boost a pump - Header package LG Motorsports...Borla type S exhaust... stock bottom end !!!car is insane actually ...

 

Single nozzle is plenty on the Alky kit.

You'll want the 81mm blower pulley. With your upgraded cam and long tures, you should see about 9.5psi. Here's the belt that's been shown to work well http://www.thequietbelt.com/#the-art-of-silence Don't remember the size, but maybe Streek14 will chime in. He's young and still remembers things like that....That combo should make the power you're after. You can do it on a 6 rib as long as you use a good belt and your tensioner isn't toast.

You do need to bump up the injectors if you're still running the LS9 injectors that the kit comes with. +-72#ers will handle anything the Heartbeat can dish out.

I haven't done anything to my hood and I only have a small mark where a hose clamp on the throttle body touches the liner a little. A Magnuson rep mentioned that gravity being gravity....eventually the liner will sag anough where you might consider removing it. I'd do that before adding any spacers.

 

Great.. what pulley size you are running?
What injectors have you got now?
6 or 8 rip?
I assume no meth in your set up!

 

KB offer BAP in 17.5 and 20 V. Which one you recommend?

 

To answer your questions:

1) BAP: I chose the 20 volt version. Gives extra headroom and doesn't seem to have any noticeable effect on fuel pump life vs. the 17 volt version.

2) Single M15 meth nozzle is plenty for what this blower makes with the available pulleys. That's what me and oldmotorhead run.

3) Get the 81mm pulley. It's the smallest available from Magnuson, but will probably make less than 10 psi with a cam.

4) 6 rib belt is fine with the 81mm pulley. Get a Gatorback belt. I think they're actually branded "Continental" now, but should be the same. This is the one you want for the 81mm pulley: http://www.summitracing.com/parts/cel-4060967

5) You'll likely need injectors. The supplied LS9 injectors were right near 100% duty cycle on my car when I was running the 90mm pulley on an otherwise stock engine with headers. I swapped them out when I went to the 81mm pulley. I'm partial to Injector Dynamics injectors, because they come with proper calibration data. The ID850 drops right into an LS3 and will support more power than this blower can make.

6) I didn't use the spacers, and still have my stock hood liner installed. Other than some minor marks from the air boot, no problems.

Hope that helps.

 

Very helpful... thank you.

The ID850 Injectors are about 1000$ in their website. Am I looking at the right part?

 

Some good info here!

 

ID's can be had for less. PM me

 

Running the 81mm pulley ... upgraded injectors ( cant remember exactly now ) nothing fancy on the belt ... NO meth ... from what I read the " tune " is very important to play and keep safe ... I have a auto so I just put in D and mash her !!! car is a frigging blast to drive...I have installed the SLP hood so some heat seems to escape and cold air does come in at driving speeds... might help a little ...

 

Nice numbers for your set up

 

I see holley injectors half the price on 66lb. Is it a compromise or do I need the 85lb for sure?

 

Brian tells me the ls9 injectors that come with HB will be sufficient with BAP for 650rwhp.
Getting confused more! Any views will help.

 

650 wheel is a lot of HP through an A6. That's 750 or more at the crank. My 60#er's in my old LS3 were at 80% at 640rwhp. That's through an M6. A6 hp would have been closer to 600. I guess you could have your tuner watch it close on some lower power runs and see where you're at...I wouldn't, but I'm no expert. The cost of a set of injectors is TINY compared to finding out the hard way that yours aren't cutting it.

 

Dont skimp out on fuel

 

Don't skimp on injectors. The ID850s have good and accurate calibration data that will make things more consistent and easier to tune. There's much more to this than the flow rating. Matt at FSP sold me my set for a very reasonable price. Well worth the extra cash in my opinion.

As for the LS9 injectors, all I can tell you is that mine were at ~98% duty cycle making 550 rwhp through a manual trans with a 90mm pulley. This was with a 20 volt BAP and Racetronix harness. Using meth for some of the fueling will help take a load off the injectors, but not much unless you really want to live dangerously.

There's a number of factors that effect how much power an injector will support, but I don't see any way in hell those will work with a non-boost-referenced C6 fuel system, a cam, and 81mm pulley.

 

From your comments and some research, I understand that ls9 will be maxed out much much below 600rwhp. Conclusion is they are no use for me.

Also, the 08 ls3 ECM understands upto 63.5lbs. Do I benefit from the 85lb (calibration, cost, rich fuel )?
I found people happy with an upgrade to 65lbs with injectors not maxed out. If this is true, a set of Fast 65lbs will be 500$ less than IDs.
I will get the IDs if other products will get me in troubles. But saving with no compromise is not bad I guess.