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I know this has been done before but I just got the dyno results today and wanted to share. I built this because my LS6 died and I intend to do a street turbo setup in the future. Thought I'd post the results from putting LS6 heads on a LS3 so people can find this in search results down the road.
My setup:
2002 Electron Blue Z06
New LS3 block with forged pistons & rods, stock LS3 crank
New mild NA/Boost cam
New Monster Level 3 single disc clutch
Re-used my old LS6 heads / intake
Re-used my ported LS2 throttle body
Re-used my LS6 LG headers + high flow cats
Re-used my Vararam VR-B2
OEM C5Z titanium exhaust
Results:
414whp, 419 lb-ft (Dynojet)
Ran out of airflow due to my heads/intake
This is the craziest combo. It makes more torque than power and the torque curve is flatter than Kansas. Tons of fun to drive - the midrange is just nuts. It's a lot more robust than any LS I've driven (aside from a LS7). I love it. It feels like a crazy strong engine GM should have made from the factory.
Last edited by Torque Obsessed; Dec 7, 2016 at 08:25 PM.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
your car looks good... how did you get an ls2 tb onto the ls6 intake?... I have seen some epoxy part of an ls2 intake onto the ls6 so the tb will fit, not sure I would want that on a boosted application though
Cool , saved a buck or two but can up grad with the LS-3 bottom end . I right now am looking to put a little more HP in my LS-6 it has right now on LMR rollers 440 RWHP a fun ride . The bottom end ( ROD BOILTS ) of the LS-6 weak over 7000 RPM. So have to take out the motor up great the bolts and on and on PITA . You did the right thing with the LS -3 just add power .. Good deal .. Nice vette I got one just like it .. Z-16
Sorry to redirect the thread Torque, but are those cup or cup replica wheels? They are my all time favorite wheels and I didn't think they came in C5Z offsets. Can you give me the 411 on them? They look great on your EBZ!!
Sorry to redirect the thread Torque, but are those cup or cup replica wheels? They are my all time favorite wheels and I didn't think they came in C5Z offsets. Can you give me the 411 on them? They look great on your EBZ!!
Sorry to redirect the thread Torque, but are those cup or cup replica wheels? They are my all time favorite wheels and I didn't think they came in C5Z offsets. Can you give me the 411 on them? They look great on your EBZ!!
Sounds like a cool project, just curious why you used ls6 heads on it, did your ls3 come without heads Im assuming?
I wanted to save money and had to pick between the options:
New LS3, complete OEM engine
New LS3 block with forged pistons/rods from an engine builder, re-use LS6 heads/intake, mild boost cam
Both were about the same cost. Since I was planning to add turbos, I wanted to upgrade the internals to handle boost. The NA results weren't really important to my goals. But it turned out very interesting! I actually like this setup much more than the LS3's I've driven. It feels very strong.
Last edited by Torque Obsessed; Dec 9, 2016 at 09:51 AM.
Sorry to redirect the thread Torque, but are those cup or cup replica wheels? They are my all time favorite wheels and I didn't think they came in C5Z offsets. Can you give me the 411 on them? They look great on your EBZ!!
Thanks! They're Cup replicas in C5 offsets from a forum vendor. I think I found at least two forum vendors who sell them actually. Here's what I'm running.
- 18x9.5 +57 front & 19x10 +56 rear Centennial Cup wheels in Chrome from forum vendor House of Wheels
- 265/35/18 front & 295/30/19 rear Bridgestone S-04 tires
- Lowered all the way on stock bolts - no rubbing or other issues; fenders are not rolled or modified.
Now... There's a caveat to the above. I bought these wheels and enjoyed them for a while, then later upgraded to C6Z brakes, which do not fit under the replica wheels up front. I had to add a spacer to clear the bigger calipers. If I was going to do it again I'd just grab a set of OEM Cup wheels which would stick out farther, but would also clear the brakes without a spacer. Summary: If you're running stock C5Z brakes, the replicas fit great, but if you're planning to upgrade to larger brakes you'll want a different offset than I have.
Last edited by Torque Obsessed; Dec 9, 2016 at 09:50 AM.
your car looks good... how did you get an ls2 tb onto the ls6 intake?... I have seen some epoxy part of an ls2 intake onto the ls6 so the tb will fit, not sure I would want that on a boosted application though
Honestly I'm not 100% sure. I think MTI told me they installed a ported LS2 TB several years ago on my LS6 and we re-used it on this setup. I don't know how they did it. I'd have to go find the paperwork from that build to be sure; it could be a ported LS6 TB or something else entirely. I'm probably about 80% sure we can trust my memory and it's a ported LS2 TB.
Honestly I'm not 100% sure. I think MTI told me they installed a ported LS2 TB several years ago on my LS6 and we re-used it on this setup. I don't know how they did it. I'd have to go find the paperwork from that build to be sure; it could be a ported LS6 TB or something else entirely. I'm probably about 80% sure we can trust my memory and it's a ported LS2 TB.
I don't honestly know for a fact that the stock heads should be modified for the larger bore to improve flow and reduce the chance of hot spots. But this, in conjunction with a quality CNC will also really help your NA power. Also, increasing the chambers will lower compression for your eventual turbo installation. A quick pic of your intake/TB will tell us what's going on there.
PS; Love those wheels, but 10" is kind of narrow for the rears. Is it the picture angle, or does your car have flared rear fenders?
Cool... "you will make more power and tq though with a set of LS3 heads with a smaller runner then factory LS3 260cc"... Even a set of LS3 oem heads will make more... Reminds me of my build kind of... Im running a Forged/Built LS7 block with a LS3 Topend... hahaha
I knew 1 guy who did this on a C6 LS3, Threw on cathedral port LS6/LS2 heads just so he was able to run a Kenne Bell C5 blower kit that was only made for the C5 Cathedral heads... Car made like 800+whp
The LS-3 heads ported make way more power that a set of LS-6 heads you can spent big money on the LS-6 heads and still not be in the same power range as the LS-3 heads . The LS-3 heads a step up from the LS-6 heads .. Don't waste your money on the LS-6 heads .. Your in the world of the LS-3 now you can make some big power and not hurt the motor..
I don't honestly know for a fact that the stock heads should be modified for the larger bore to improve flow and reduce the chance of hot spots. But this, in conjunction with a quality CNC will also really help your NA power. Also, increasing the chambers will lower compression for your eventual turbo installation. A quick pic of your intake/TB will tell us what's going on there.
PS; Love those wheels, but 10" is kind of narrow for the rears. Is it the picture angle, or does your car have flared rear fenders?
It's just the picture. The fenders are stock, though I sure do like how they look here.
LS6 - LS3 combo results
... how did you get an ls2 tb onto the ls6 intake?... I have seen some epoxy part of an ls2 intake onto the ls6 so the tb will fit, not sure I would want that on a boosted application though
