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Old 08-22-2014, 09:51 AM   #21
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Originally Posted by hankclaussen View Post
What tire size are you running? I am having trouble making sense of these numbers given the ratios and using FM's calculator page.
I am running 195/50/15's but they seem to be a bit "short" compared to their theoretical 22.7" diameter. Either that or my tachometer is off

Interesting side note. With MS3 is the tachometer driven by the MS3? I ask because Data logs show tachometer to be accurate at idle, and my rev limiter is currently set at 7200 and that is where it kicks in on my tachometer... but data logs showed only 7000 when limiter kicked in.

If the car wasn't torn apart for my BEGi S6 installation I would go out and data log speed vs RPM (steady state runs vs quick run through gears like most of my logs) to see what I could dig up.

Later,

Keith
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Old 08-23-2014, 02:13 AM   #22
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Originally Posted by curly View Post
In less you're going for insane lap times like Bob, there's no point. BPs are crying for mercy at 7,000 rpms, I can't imagine what they feel like at 8,600. Very m.net post, yuck.
I really don't use all the revs to do fast laps on the track. Although judging by the fact that the video I took when I screwed up this motor at Pacific I was heading for running out of 6th gear with the 3.636 rear end. Rapidly rising speedometer was just reaching the 140mph mark I was already in 6th gear and hadn't reached the kink yet still had half the front straight left. It dropped power and my instinct was to upshift which turn turns out doesnít work from 6th and I went to 5th. New repave of turn 8 just puts you on the front straight stupid fast would have liked to have gotten a full lap I think I would have crushed it.. I discovered my timing I think jumped advanced about 6 degrees somehow and knock sensor flaked out.

What the 8600 rpm rev limit is for is autocross. Its way past the power band but it allows me to reach high enough top speed without shifting and yet I have a gear that I have instant throttle and boost response coming off any slow mid or high speed autocross corner in second gear. The initial acceleration is way more important for autocross than running it out past the bulk of the powerband. Itís been working real well for me this year I should have planned to go to Lincoln my Pax performance against national level drivers this year says I should be in the mix at the top. I'm contemplating focusing on autocross next year seeing how far I can go.
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Old 08-23-2014, 02:36 AM   #23
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Originally Posted by bcrx7 View Post
You can technically change the valve springs with the head on by pressurizing the cylinder with air at TDC and removing the springs and swapping them over!
Iíve changed valve seals in the car without removing the head before. Rope down the spark plug hole used the piston to hold the valves up and I made a tool that I could lean against with my chest to compress the valve springs while I dealt with the callets retainers. Worked quite well actually seemed easier than having the head off and using a valve spring compressor.

Unfortunately this time the head needs to come off. Pretty sure combustion gasses are making it from the combustion chamber to the water jacket under load I donít think itís going through the head gasket. Combustion chamber had seen enough force to knock a hole in a piston. Rods and rod bearings looked fine however.
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