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So I took the plunge and went from the max effort setup the M6 Z28 I bought came with and went with a more conservative cam and a set of Tony's MMS 220s. I've had the car back from PCM of NC since Friday and although I haven't really stuck my foot in it yet, I'm definitely happy. The goal was the same or more power than the car was making with much better fuel economy and low end power.
Old setup:
MS4 Cam (239/242)
GMPP Ported LS6 heads with gigantic 250mm intake runners.
LS6 Intake
Spec 3 Clutch
Strange S60 Rearend
4.10s
Car made 426rwhp and 380 ft/lbs torque.
New setup:
Comp Cams 226/232 Cam specced by Tony
MMS 220 Heads milled to 62 CCs. Aiming for 11.5:1 compression.
Intake clutch,gears, and rear end remained the same.
Car made 438 rwhp and 402 ft/lbs of torque. At first I was a tad disappointed until thinking about the fact of all the additional money people have to spend to hit 500rwhp including cutting out any source of parasitic loss. And this is still with the old LS6 intake so I know I could pick up a ton of power with a Fast setup. And I definitely can't complain since this is through an S60 rearend, a heavy clutch and I'm sure the heavy 18 inch rims don't help either.
In the end, its much more cost effective for me to funnel some more money into the nitrous kit I havent installed yet and use a small shot anytime I want to hit the numbers someone else spent a lot more for.
I haven't filled the car back up for mileage but I can already tell fuel economy is going to be much better and I haven't been doing a whole lot to help that matter with my foot in it all the time. The car is backfiring and popping a good bit after letting off of the throttle at certain RPMs (and with dumped true duals this is LOUD) but the bucking and surging days of the MS4 are gone. It isn't annoying but I'm not sure if I should be concerned about the tune due to this or not. Throttle response is great and there's no more waiting until 4000 RPM for the car's power to really pick up.
To me that seems about right. Maybe a touch lower than I'd guess. You'd gain some with a fast 102 and then again some with the 102 throttle body. 4.10s dyno lower than 3.42's, and that strange is heavy. That's regardless of the clutch and rims.
Also, looks like that double hump torque curve from the MS was smoothed out. Probably a lot more fun to drive.
Congratulations!
Looks like you picked up ~25 lb ft from 2700-3700 RPM that
Must feel a whole lot crisper. FAST 102/102 TB on your combo
Worth at LEAST 20-25 RWHP out of the BOX! Vs LS6
MAMOFIED 35-40 RWHP, 460-480 RWHP with a medium sized
Cam and a relatively heavy driveline.
I think the results are excellent with all the obvious room for improvement still in place (and factoring in the heavy power robbing driveline your running).
You went with much smaller heads from a previous baseline of CNC ported OEM castings (not unported stock castings).....went with a much smaller cam....and you picked up a bunch of power everywhere including peak power which is difficult to do with a cam that much smaller (we arent talking about a few degrees smaller).
Huge gains across the entire curve....you need to go mash the throttle on that thing.....its going to feel better than you think because your average gains in HP and TQ is very significant. Some mods give up bottom to get that 10-20 more ponies on top.....you picked up everywhere and your going to feel that when you hammer down on the throttle
Also....and this is a big also.....part throttle response and tip in must be improved in a huge way and while you never see that on a dyno (only showing you WOT stuff), thats the kind of thing that really makes driving the car sooo much more fun and enjoyable.....it feels even faster due to that.....always crisp.....always alive....AND your still making a bunch more power and TQ at every RPM while getting to enjoy that. Its the have your cake and eat it to scenario.....enjoy it and get a better grasp of what was accomplished with the swap.....its very significant.
With your driveline in place the car would never be a hero on the chassis dyno but its pretty obvious it would dyno very strong regardless with a ported 102, 102 TB.....a larger 4" CAI, lighter clutch/flywheel assembly etc. as Navy Blue and others have already touched on. And your running steep gears which hurts the dyno number....all things considered your making excellent power and TQ in my opinion.
Also, Im pretty sure I sent you a 226/230 cam (not a 226/232) so its even smaller than you originally stated and the lobes I spec'ed for your build were a little smoother and easier on parts than I typically run.....that cost us a few ponies also but would extened spring life and run a little quieter as well.
You did great....obviously the install and tune went reasonably well or the results wouldn't be this good. Im actually quite surprised how well it carried with the LS6 intake.....go rip some gears in that baby snatching them around 6800-6900 and let us know how good it feels! Its a 7K player with the ported 102 without a doubt and the entire curve will be fattened up again.....not just gains up top
Curious what pushrods you are running. I went from 5/16 to 3/8 double taper on my AFR 205's (Tony worked the heads for me) and it helped the upper RPM smooth out and I actually picked up about 6 hp just from a pushrod change. I did the change mostly for longevity of the setup, but it was interesting to see what happened to the curve.
Crappy. 22mpg on the highway if I was lucky with the MS4 and probably 12-13 in the city.
Both figures are from the same dyno, yes. It may be conservative as well since this car put up 441rwhp on the old setup on another dyno.
Tony, yeah I couldn't recall the exact cam specs and was too lazy to go snag the box, I just remembered the intake duration. Throttle response is amazing and I still haven't really gave the car more than 2/3 throttle.
Which brings me to this question- Do I need to worry about 'break in' mileage? I was thinking of getting about 500 miles on the engine before really stressing it.
Crappy. 22mpg on the highway if I was lucky with the MS4 and probably 12-13 in the city.
Both figures are from the same dyno, yes. It may be conservative as well since this car put up 441rwhp on the old setup on another dyno.
Tony, yeah I couldn't recall the exact cam specs and was too lazy to go snag the box, I just remembered the intake duration. Throttle response is amazing and I still haven't really gave the car more than 2/3 throttle.
Which brings me to this question- Do I need to worry about 'break in' mileage? I was thinking of getting about 500 miles on the engine before really stressing it.
What are you breaking in??
The cam is a roller and doesn't require it and Mamo Motorsport heads beg for WOT right out of the box.....LOL
Seriously though....heads are all dialed in and need nothing in the way of break in.....cam is pretty much the same story. Break in is only required typically when your dealing with a new shortblock to help seal the rings but honestly that requires load and going WOT on a new engine once the A/F ratio is dialed in (and the timing set properly) is actually desirable cause that's exactly the type of load that starts sealing the rings.
Its a performance engine.....they don't need to be babied if they are built properly
Biggest thing I see is that you went from a gigantic cam to a very mild cam and made more power! Ditch the stock LS6 intake and you'll make so much more. On it's face it seems like a big chunk of money and hassle to do a FAST 102/102 for a seemingly smallish gain, but you'll be happy you did.
While I don't have a dyno prove it I'm quite certain my results mirror the OP's. My old setup(PRC 5.3's/228r-114) was 419whp/375wtq and felt terrible down low. Now it feels about the same up top and maybe carrying a little better due to a better designed valve train but down low is the best part. Crisp throttle and a lot more torque down low. Once I get the money for a new intake (LS2 now) I'll head up to Nijmegen(look it up :-) to the nearest dyno and find out.
12-07-2015, 08:11 PM
Mamo 220 Build Complete. 
Throttle response is amazing and I still haven't really gave the car more than 2/3 throttle.
