Lucky#13

Cheers,

so I have lsa blower with lsa heads on top of lq4. 4l80e tranny wih 2800 converter and 3.3 gear behind the engine. Now I have stock 096 cam (198/209 .500/.500 119.5 lsa). Looking to wake up the combo a little bit with a cam swap. I have stock ls9 injectors and KenneBell BAP on the fuel side. Cast C6 vette manifolds with C6 cats on the exhaust side, rest of the piping is free flowing 2,5´ stainless with crossover and magna mufflers.

I was going to go with ls9 cam, but something came up and now I have make the decision again. Have read good things about the Summit SUM-8715 cam.

Car is a summer daily toy which sees track time maybe once or twice a year. How do you think these cams would differ on my setup, both engine character and tuneability wisely?

All help is much appreciated!

Cam specs:
222/233 @ .050 valve lift and .600/.575 lift with factory 1.7 rockers and a 115+3 LSA SUM-8715 cam
211/230 @ .050 valve lift and .558/.552 lift with factory 1.7 rockers and a 122.5 LSA LS9 cam

V8sounds

iTrader: (1)

The LS9 cam definitely has less overlap, as well as being smaller overall. That being said, I would likely run the SUM-8715. I don't feel that either would have very bad manners on a 6.0, especially with a PD blower; and the Summit cam will almost certainly make more power; thought it seems you are probably fuel limited either way.

joyridin'

iTrader: (1)

I would not go with either one of those cams.I would go with a BTR Stage 1 or 2 PD cam. They are both pretty mild and you will get more horsepower for the same amount of work.

68Formula

The guy that sent you the wrong cam, sort of did you a favor. The Summit-8715 should work well with the blower and is a much better choice over the factory LS9 camshaft.

Lucky#13

Thank you all for your thoughts.

New tune is required anyway, but which one will be harder on tuner? On fuel side there is DW300 fuel pump with KenneBell BAP and ls9 injectors. So the injectors are the limiting factor? What would you recommend as an upgrade? (Budget is always a big factor)


You are quite right there. I don´t yet have the genIV timing cover/sensor/wiring kit yet, so the summit cam would be great budget wisely as it would bolt right in.

I do have PAC 1218 and the hardened Manley pushrods 7´400. Both cams would work with them. On the other hand, all the BTR PDS cams would not work cause the higher lift, right?

Any other thoughts/suggestions?

JosephIV

iTrader: (14)

I don't see a problem with your fuel setup unless you're burning E85 and shooting for a high horsepower # on higher boost. I think the LS9 injectors and DW 300 / BAP should see you safely make up to 600 RWHP at 58 PSI base fuel pressure to 65 PSI fuel pressure boost referenced on 93 octane gas.

I'm just some schmuck on the internet though, do yourself a favor and contact somebody who is used to tuning LSA cars and ask for advice. Vengeance Racing, Complete Street Performance, Lingenfelter, RPM, etc. We can throw around boost, injector rating, and horsepower #'s but until you see what happens with your setup and what your injector duty cycle is when you run it we won't know for sure.

There are places that resize and flow LS9 injectors if you end up needing bigger. Might be less expensive than buying Deka 80's or other injectors. Selling the LS9's would obviously offset cost if you did step up to bigger. Good luck!.

68Formula

Correct. Although sometimes it's possible to go slightly above spec. The risk is two-fold. One, you could get into coil bind. Second, depending on the spring rate, lobe aggressiveness, and the intended rpm, you could get into valve float (which again, could also lead to coil bind).

Lucky#13

Thanks for your opinion. Burning 98 octane gas up here. Boost is a bit higher because 2,7 upper pulley.

68Formula

Another option is the SDPC LS9 Powermax Camshaft: https://sdparts.com/i-24138756-sdpc-...s-engines.html

stevieturbo

RH has done a load of videos lately with various cams including the LS9....it should answer most questions, with evidence to support any choices.

Lucky#13

Thanks for a great tip! Very nice option, I do have dig deeper on this cam.

Richards vids are most informative. I really start to like more these SUM-8715 specs, especially because the most important power area for me is low and mid range. But at the same time I have say that SDPC "LS9 POWER MAX" CAMSHAFT with 216/239 @ .050 valve lift and .600/.600 lift with factory 1.7 rockers and a 120+4 LSA is also very, very tempting option.

Lucky#13

Thanks for everybody for your input. I made up my mind and ordered the SDPC "LS9 POWER MAX" CAMSHAFT with 216/239 @ .050 valve lift and .600/.600 lift with factory 1.7 rockers and a 120+4 LSA. I will report results, but unfortunately it will take some time due the delivery time etc. installation will take place somewhere in june or so.

Mavn

iTrader: (3)

Summit 8715 is the ****.

NitrOmm

iTrader: (1)

un-related but I see why you reference this guy RH. His vids are spot on !! No Bullshit, back to back & to the point.
Thanks for the direction.

Project GatTagO

iTrader: (7)

Since the OP has made the purchase decision, my comments are not intended for him, but maybe for others that find this thread in the future. I have experience with the Summit 8715 cam in my 5.3L NA and I have experience with the LS7 cam (cam specs are almost identical to the LS9 cam) in a 6.2L, also NA.

The Summit cam is very easy to tune. Mine idles smoothly around 42-44kPa and I have it idling around 725 rpm. It also pulls strong from idle and doesn't seem to run out of steam even past 6500rpm. I am a big fan of this cam and if I ever build a power adder engine, this cam will be at the top of the list to consider.

The LS7 cam in the 6.2L is also very easy to tune. Keep in mind that this is the cam that GM includes with the LSX376 B15 engine. It idles very smoothly. Smoother than the Summit cam. Some people might even think that it is too smooth. I think it makes great power and it has no problem pulling my 4000 pound 1970 GTO around.

Andrew

forcd ind

iTrader: (7)

I have the Summit stg 2 cam, was thinking of pulling it in favor of the 8715 cam to get down more in
my driving range, but not sure if the effort is worth it or not. I want it to idle like a stocker, not able to hear
the exhaust, and make 1000 HP, lol.

Mavn

iTrader: (3)

My car makes 900+ Wheel on medium boost with the 8715 cam. put it in, you will love it. car doesn't chop at all. super smooth.

silversweetZ

iTrader: (11)

Don't mean to hijack but MAVN, whats your thoughts on the 8706? Do you like the 8715 better for the longer exhaust duration and better LSA? I almost pulled the trigger on the 8706 until I saw your two threads on the 8715.

Mavn

iTrader: (3)

I put the sum 8706 in my s10 with a 6.0 and it worked great. I've had the best luck with the stage 1 . Carrys power to 7800 and makes a great tq curve. I see no reason to go bigger. Again this is personal preference . The smallest cam you can get to work, the better off you are !

TT427

iTrader: (1)

I remember the big cam test one of the magazines did with all the different factory cams, they had the 3 different Crane grinds at the end. The Crane 210/218 always stuck in my mind, lost almost no power down low at 2500 to the smallest cam and almost equaled the Ls9 cam in peak power. Seems a person couldn’t go wrong with something similar in specs, can make big broad power with under 220 duration cams.