Ls3 lg g6x3 full bolt ons low numbers
 

2004 c5 zo6
ls3 motor swap
lg g6x3 cam
ls7 lifters
smith brothers trunion kit
btr 660. Springs
ls3 intake manifold with stock ls3 injectors
ls2 Vmax ported tb
vararam intake
ati 25% ud pulley
Improved racing crank scrapper


arh 1 7/8 headers catless x pipe
corsa extreme

act dual disc clutch
3.73 gears

The car put down on a mustang dyno
431rwhp
431 rwtq
91 pump gas
10.7 compression /stock

seems low for the set up and seeing other identical builds put down north of 470 to the wheels

https://cimg4.ibsrv.net/gimg/ls1tech...5cef50ffc.jpeg

Peak is way too soon..should make peank hp around 6400-6500.

my point exactly

i was thinking maybe the cam wasn’t installed right but then again this a big cam and I would have ptv issues,maybe

I’m kinda in the same boat but different build with ls3 top end.

I have a 416 with BTR stage 4 cam stock ls3 heads and Holley hi ram. My car made 511 at 6100rpm. Motor is 11.2.1. We were tuning the car on nitrous and I had a ls7 lifter collapse. I always blamed the heads but I wonder if it was the lifters with the 660 springs. Motor only has 2500miles on it. The car is currently apart right now. I’m going with Johnson short travel link bar lifters and new springs for insurance then measure new pushrods.

Should be back on the dyno within a couple weeks. I’ll let ya know what happens. Lots of people told me the stock heads shouldn’t restrict RPM but would restrict HP. I’m no engine builder/professional but believe the people that have told me this.

You might have just had a bad lifter. Stock LS3 heads are normally good for around 600FWHP

Swap out to some Johnson short travels and port those heads. That cam has like a .640+ lift and did you degree the cam?

Should peak higher than that with a 235*/244* duration and 111* LSA.

My much smaller cam has peaks HP/TQ at 6600/5400 rpms....and with 7.5* overlap, probably has much better drivability.

Plus....I roll with 11.3:1 compression. The LG g6x3 cam really isn't a good match with stock compression....no mater what peak HP others have gotten. Unless.....you ALWAYS drive at 6500+ rpms.

Still, on a Mustang dyno....those peak numbers ain't half bad. Just a bit low in the RPM curve.

KW

Were those other builds Dyno'ed on a Dyno Jet?

If so your looking at 12.5% - 13.5% higher numbers than you will see on Mustang Dyno.

Just a 10.0% correction would put RWHP at 473.1, 12.5% 483.75

My engine makes 360 RWHP on Mustang it's tuned on VS 406 RWHP on Dyno jet I used for compairson purposes.. On long Black Dyno it makes no difference. .

I think your issue is on the induction side. I do not think a ls3 intake and basically stock size throttle feeding a 416. I bet if you could see the data you are pulling a vacuum at WOT.

Def peaked low. Torque at 4800 says cam is about right. Power should peak around 6500 on that cam. Maybe try a sniper and 102 throttle just to support some rpm

stock ls3

Agreed that it peaks low but the graph looks smooth. If they are running a true MD calibration those are pretty good numbers. It would be around 490ish on a Dynojet. We run a "correction" factor on our MD dyno to display DynoJet numbers. The correction factor is 15-16% IIRC. We got tired of customers complaining why their car didn't make the power the internet said it should. We talked to MD and they gave use a math calibration to spit out Dyno Jet numbers.

At this point my concern is the rpm and why it drops sooner then I think this cam is designed

ls7 lifters and the valve springs ?

I'm not sure of the LG cam specs (don't buy cams from people who don't give you specs) but my LS3 made 470 on a Mustang dyno and pulled well to 7000 with probably a smaller cam.

I had same lifters, springs, pulley, headers, gear ratio etc. However I did have a FAST 102 that makes a good difference above 6000RPM and I was on 93 octane fuel. What is your timing up top on 91 octane?

LG G6X3 cam specs- 235/244, .647/.612, 111LSA

What length pushrods? My bet is that or cam installed wrong.

Yea, something is off. Main thing I see is the shape. Tq dropping off right after about 49xxrpm. As it dropping so hard it does not even make more power than tq along with the peak around 6k. That setup/cam should most definitely make more power than tq.

7.4 pushrods not stock

cam was installed dot to dot

The valvetrain is quit considering the cam size

numbers are from a mustang dyno and not dyno jet

If the cam was installed wrong torque would peak low. It is peaking at 4800 right where it should.

Check your map readings at wot. I bet it is pulling a vacuum. Indicating induction not keeping up. Starving for air at higher rpm.

That cam will rev to 7k and as said bolton LS3's can make that number. It's more than just an intake issue, besides the fact that very few LS motors ever make the same torque number as HP.