RedZ4me

Well weeks after purchasing from Tony Mamo my ported MSD, I was finally able to spend the day at the shop for the install and tune.

Some history - shop is great, you can hang out all day (not get in the way though) and watch things getting done. it's probably the premier Corvette/Camaro shop with a super reputation. This same shop did my PRC heads install, MF103 intake, Trunnion upgrade, and tune but past tuner is no longer as he's oftened referred to as 'cut&paste' and spends little time on cars tuning properly. Anyways, car was running great BUT in the past/ my first round, never saw the guy tune it even though I asked to be there but results (I was told and given a printout was 524 rhp/450 torque on full stock exhaust - good right?? At least I thought so.

Today, we did a baseline. Why? Owner and tuner insisted because past tuner was known to lean the run out, get the good numbers and back it off. They have come across this on almost all the cars past tuner did - nice eh?? Owner of the shop parted with him and now has an exceptional tuner who has done hundreds of ls tunes and spent a great deal of time today on my car. Both advised me running the baseline dyno today will give us different numbers from past tuners 'claimed' numbers and they were right - 494 rwhp 30 less than I thought I had for 2 years.

Today - install went well, water pump was clearanced slightly, intake went on well, all buttoned up, all items checked and some run time on dyno to verify some settings and parameters. Slight cool down and off we go.

Dyno run 1 - very little timing, car pulls off a 514 rwhp just to check things out. Engine brought to about 7k rpm but pulling timing. Tuner has seen this countless times this time of year as in the winter, our stations run a winter blend of fuel. ** Keep in mind I store my car topped up with 94 octane and only had it out twice so far this year (busy but that's another story) Each time topped up with fresh fuel but there is probably a mix of old fuel/new in the tank. So tuner is confident it's a fuel issue.......pulled the plugs and mint shape.

Dyno run 2 - few tweaks more and 524 but still pulling timing, anywhere from 5-10 degrees across the range ......he showed me all this on the laptop with the hp tuners software. Nothing hiding/no secrets - Again, feels fuel crappy. This number achieved at a low 17 degrees only........very low, told should be in the 22-26 area???

So enough for today - tuner took it for a normal street drive as I wanted to ensure the 102 TB is easily driveable and it is, not bad at all.

The bad - well, not happy really but I'm not considering these 'final numbers' yet. Considering the timing is very low, he is confident when I return for another attempt in mid-july with more fresh fuel, we'll gain another 20 rwhp. In fact has installed a few ported Mamo intakes with TB achieving 40-50 rwhp so that's good

So car runs good overall and drove home (about 40 min drive) with good driveability.

The UGLY (maybe) - after the tuner did his drive, I hop in to leave and notice a growl and low rpms that can be heard more in the car than out - at first I thought maybe the msd hitting the fire wall ?? (thought I read that in a thread here of possible contacting the firewall)
Hard to describe but it's not a tapping or ticking, it's a growl that can be heard at idle and lower rpms in the cab - almost like a throwout bearing sound but it isn't that - i washed the car before putting it away and heard it as I restarted the car and low revs. As I drive away from a light in first and second,(unsure of other gears as wind noise starts to overpower) with light to moderate throttle, you can hear it.

I have no codes, no tapping/ticking, idle is great, starts up fine, no funky exhaust smoke etc....

Sorry for the long rank - I'm really bummed out - crap like this really gets to me, making me ask why didn't I just leave things alone as it was running fine.

Video, I have a iphone video but having difficulty uploading - any help will be appreciated.

So not sure, maybe a rocker?, maybe an inner/or outer valve spring broke? Running ok as mentioned just hoping don't have some internal engine damage

Unreal

Tune stuff like you describe is VERY VERY VERY common.

Local guy had a intake/tune/heads done on his car. Stock exhaust, no headers, no cam. Tuner told him it made 520rwhp. Did a base line tune up here, made 440rwhp or so. A bone stock z06 made 460 right after, so he actually lost ~20rwhp with his mods/tune. Its amazing what people do to sell crap and make their tunes look good.

Dan_the_C5_Man

Very good chance the manifold (or something attached to it) is just slightly grazing the cowl or firewall.

MSD really pushed the dimensions on this manifold, a bit too far actually (hense your water pump clearancing). You sure it isn't just barely touching?

RedZ4me

^^^

Not sure of anything today, just hoping not an internal issue like like rod or crank bearing . Oil pressure is good though. Thanks for trying to help, this will be on my mind until i can get back there (busy time for me now)

MyLS1Hauls

I had the same noise with my FAST. It was rubbing the firewall slightly. When I removed it, you could see where it was rubbing. The engine really needs to be lowered about 1/8" to totally remedy it. It will still rub a bit when the engine torques at full throttle.

Must_Have_Z

RedZ4me - do you have stock cam? I didn't see anything mentioned in your post about a cam. If you're on stock cam, I would consider your numbers really good! My Z has stock cam, headers, CAI, ported heads, Corsa exhaust. I'm at 487RWHP on a mustang dyno. I'm considering the MSD and NW combo, but I'm not sure it will gain me much with stock cam, so I may just go with a ported stock TB and LS7 intake.

njk4o5

seems like good numbers if stock cam/heads

southspeed

It's barely touching the firewall on the back passenger side. Mine did the same thing. I searched for a while but finally had to pretty much lay on the drivers side of the motor and shine a flashlight back there and could barely see a spot where it was touching. I actually had a thread on it in here. I took a long skinny flathead screwdriver and tapped it through with a hammer then pulled it back out. No more vibration sound ever since.

RedZ4me

^^^^^

Found your thread (below) and believe I have the same issue - just so tuff to see back their even with flashlight so not sure where it's hitting (assuming it is)

Drove today and motor seems ok so probably is this:

https://www.corvetteforum.com/forums...e-install.html

RedZ4me

No mild cam that's so driveable, won't change it. PRC heads. with 5-10 degrees being pulled across the range, I'm sure I'll be at 550 rwhp on the next visit assuming it is the fuel. find out next month but it does rip on the street for sure

RedZ4me

No - mild cam. I've past those younger years of ruining the driveability

southspeed

Look in that thread where trs cobra clearances his firewall. Thats the same spot mine was hitting but it was easier for me to get at it from the drivers side. I'd bet money yours is touching right there.

RedZ4me

thanks Southspeed and others - so tuff to see in there, was gently prying around today, drove around a while and it is much less but not gone so I move something around Will try this week sometime again.

rio95

This is probably nothing major so don't get too discouraged. I agree it's probably hitting. It seems like the lower hinson mounts are probably a good idea with the MSD....

If u have a 06-07 I'd make sure the alternator fins aren't rubbing internally. That happened to me and would pull up to 10deg of timing at wot.

Also, the nw102 makes some noise that you might not be used to.

RedZ4me

^^^^^^
I think you are right, out for a few hours (had day off) and she runs good - except this occasional gurgling sound - same as southspeed member described and yes that 102 is sucking some air!

Unreal

The contact of the MSD with firewall could be causing the knock. After that is fixed, relog it. That alone would be the 5-10 degrees of KR.

RedZ4me

good point, thanks!