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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
So, I know there was a lot of discussion about tightening the hex bolts on the MSD after install, but frankly, I didn't pay much attention at the time because I didn't have an MSD intake. So my question... how do you tighten the clamshell bolts at the back of the intake?
Do you have to take it off? Did you make a special tool?
So, I know there was a lot of discussion about tightening the hex bolts on the MSD after install, but frankly, I didn't pay much attention at the time because I didn't have an MSD intake. So my question... how do you tighten the clamshell bolts at the back of the intake?
Do you have to take it off? Did you make a special tool?
You can do what I did and use RTV on the clamshell gasket and the top of the bolts.. Two benifits, no leaking and no need to touch them again. YMMV
Last edited by Dan_the_C5_Man; 12-01-2017 at 10:17 PM.
The clamshell gets tightened, then install the manifold, then tighten the manifold to head bolts. I believe that is what you are asking. There's basically no way to tighten the rear clamshell bolts once installed.
I used the RTV on mine and tightened the hell out of the mounting bolts. I applied ARP lubricant on the threads to prevent galling. I've put around 1500 miles on it without an issue. They were tight in my last inspection.
That is a great analogy Derek.... I have been on the fence regarding changing my Fast to the MSD... EVERYONE I talk to gain real HP/TQ over the FAST.... I do see one "possibly" in my future w some 265 heads.... Hence the word FUTURE.....
Originally Posted by wantbluC6
Sounds like what Dan did would fix that issue? The MSD is so far from perfect. People gotta have it regardless.
DD
Put it this way the MSD is a trophy wife, but is an alcoholic. Take the great with the sucky!
Thanks everyone... so I tightened every bolt except the rear one. No evidence of a vacuum leak, and I'll keep track of it.
Mine were tight after 6K miles, but loosened up around 9K miles. I have tightened them, but the engine miss is still there above 4K rpm and full throttle in each gear. Still trying to find the issue.
Sucks running a 600 HP car at 360 HP on a road course with many extra short shifts. The car still pulls strong until it starts mis-firing. Coil wires all test out good, spark plugs looked great.
UPDATE: today CPR found two cracked spark plug wires and replaced all of them. I had checked tthe wire resistance but missed the cracked end connections. This is very likely the cause of the engine miss. I will verify at the NFZ-AZ event on the 16th.
Last edited by AzDave47; 12-06-2017 at 07:48 PM.
Reason: cracked spark plug wires.
From my research. A professionally ported FAST vs an avg. shops done MSD is not going to get you much of anything. Need Mamo etc. Ask yourself are you chasing a magic number or want the looks or have money to burn or just wealthy and bored or none of the above? Also there are the clearance issues. Not enough for myself to WANT or NEED one. Satisfied
Glad i went back to stock from the msd headaches, if i were to do it again, would go FAST but research first. That msd should not have hit the shelves for sale
That's what I did, Mamo ported and shaved MSD. I wanted close to 600 whp, while still being able to daily drive it, and take it on trips to San Diego and Irvine, Ca (traffic) because it was replacing a blown C5Z with 600 whp. At 585 whp, and a few trips to SoCal, at 24 mpg average, goal met.
Mine were tight after 6K miles, but loosened up around 9K miles. I have tightened them, but the engine miss is still there above 4K rpm and full throttle in each gear. Still trying to find the issue.
Reproducible, or somewhat random? I'm guessing you've logged runs and still no dice. What about on Joe's dyno - did it do it there too?
Mine were tight after 6K miles, but loosened up around 9K miles. I have tightened them, but the engine miss is still there above 4K rpm and full throttle in each gear. Still trying to find the issue.
Sucks running a 600 HP car at 360 HP on a road course with many extra short shifts. The car still pulls strong until it starts mis-firing. Coil wires all test out good, spark plugs looked great.
That stinks that your engine is misfiring Dave. Could your tuner run the engine under load and selectively turn off injectors to see if the misfire goes away, or if the loaded hp varies? There's gotta be a tuning hack to trouble shoot this. Hopefully it's missing on one cylinder, seems easier to troubleshoot if so.
Did the misfiring begin after the head/cam install? Could it be a loose engine ground? Crank and cam sensor sorta comes to mind, but that seems less likely, and probably ruled out by some other logic.
Mine were tight after 6K miles, but loosened up around 9K miles. I have tightened them, but the engine miss is still there above 4K rpm and full throttle in each gear. Still trying to find the issue.
Sucks running a 600 HP car at 360 HP on a road course with many extra short shifts. The car still pulls strong until it starts mis-firing. Coil wires all test out good, spark plugs looked great.
I had a similar issue with my old LS1 - turned out to be a bad spark plug wire.
I believe I've also seen this symptom tied to a broken valve spring - are you by chance running duals? Even if you aren't, I've seen single springs break but not drop the valve.
Last edited by Dan_the_C5_Man; 12-05-2017 at 10:13 PM.
The engine seemed to run fine at the NFZ October 1/2 mile with no miss evident after the installation of the ARH 2" and ID725s. Speed was down over Pfadt by 5-6 MPH but it was for others as temps were 20* hotter than the prior event.
A week later on a Vette Sette driveout, I got on it strongly in 3rd gear to above 6K and the miss was there. The following weekend the miss was consistently there above 4-5K rpm and I'd short shift . It pulled strongly until it got up into that rpm range. I checked the plugs (looked great with light brown and normal gap on all plugs). We checked back in the pits and there were no codes, I did not run a data logger in the road course events. I checked the coil wires and they were all 8 or 80 ohms (not sure of the units, but all consistent. I found the MSD bolts loose and tightened all that I could access. I pulled the rocker covers and all seemed to be OK under there. I went for a drive and fully warm got it briefly to 6K in 2nd and 5K+ in 3rd and there was no miss. Then the following weekend at another road course even the miss was consistently there at 4-5K under full throttle so I had to short shift all day again. It pulled well below 4K and had no problem breaking the rear tires (R888s) loose if too much throttle was used coming out of corners.
The car is scheduled to go in to CPR on Monday. They should be able to duplicate the problem on dyno loading and have the tuner check to see what is going on. Based on the way it runs, it seems like it must be a fuel or electrical issue rather than any hard mechanical issue. Possibly the MSD gasket got damaged, but then why would it pull strongly below 4K and have the spark plugs look so good? I'm signed up for the NFZ event on the 16th, hopefully will make it.
The car drives fine in normal street driving which is all in the lower rpm range. The engine is tuned for 91, run on 91 on the street and has 6-7 gallons of 100 added to a 1/4 tank , then topped off so both tanks are 93+ when I do road course events.
OP, I hope this is all useful info for you.
Last edited by AzDave47; 12-02-2017 at 11:40 PM.
Reason: Car scheduled to go in to CPR Monday PM
Actually I have comparisons between a lightly ported fast vs my ported MSD by Darin Morgan.... Both cars are h/c you do gain a lot actually and mine was on the first tune, and im running 13/4 vs his 17/8....here you go I wasn't a believer till I tried it....here you go this is on sae smoothing 5....
As you can see I ate the fast for lunch look at the gap....then I loose power due to the exhaust and stock Porter TB.....enjoy
Last edited by RamAir972003; 12-02-2017 at 09:03 PM.
12-01-2017, 09:07 PM
MSD intake question
