2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

concerning another project...10k ignition cut, safe?

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Old Sep 12, 2005 | 07:41 PM
  #1  
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concerning another project...10k ignition cut, safe?

Pretty much stock S4 block, lightened fly, carbureted with K/N's, open (LOUD!!) exhaust, MSD 6A (I think) and using the stock CAS and ignition control to handle the factory independant coil setup. Now, I'm not looking at making power that high, I don't think I really would anyway, but I'm having to go with an aftermarket tach (mounted in stock position) and it runs all the way to 10k. I think it would be cool to be able to use the whole tach safely.

From my research, it seems that the engine can handle 10k, but it's somewhat pointless and that real mechanical trouble doesn't start to happen until 10.5~11k (crankwalk). I've read that both S4 and S5 assemblies can handle it, but the lighter internals makes it more productive on the S5...again, I'm not really looking for "productive", only **** factor.

Anyway...essentially...is it safe to do once or twice each weekend?
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Old Sep 13, 2005 | 12:04 AM
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No real reason to do this as the engine is choking at that high an RPM.
Like I keep saying, I dunno what the deal is with revving it that high.
Ultra high RPM's just stresses the motor.

I know a guy who runs a BP with a 9.5kRPM, and you want to run HIGHER?

You need a 100psi+ OPR.
Better, deeper-groove bearings are highly recommended.

I would not want to do this on a "stock" motor.


-Ted
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Old Sep 13, 2005 | 12:11 AM
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Originally Posted by RETed
No real reason to do this as the engine is choking at that high an RPM.
Like I keep saying, I dunno what the deal is with revving it that high.
Ultra high RPM's just stresses the motor.
-Ted
Like I said...just **** factor...she won't spend any substantial time up there as 8800 will about all I can use power-wise. Hoping to be making power closer to 9400 if I ever get around to rebuilding and porting a block.

I just think it would be cool. It's one of the "lower rung" reasons I dig riding so much...watching the tach dance..
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Old Sep 13, 2005 | 12:13 AM
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Ahh... Insanity for the sake of being insane. I think you should do it and tell us at what RPM the engine explodes at. Seriously. Then we can document it and the next time someone wants to run xxxx rpms then there will be proof as to what is possible and what is not.
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Old Sep 13, 2005 | 12:21 AM
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Originally Posted by 13bpower
Ahh... Insanity for the sake of being insane. I think you should do it and tell us at what RPM the engine explodes at. Seriously. Then we can document it and the next time someone wants to run xxxx rpms then there will be proof as to what is possible and what is not.
You can rest assured that I would do exactly that! the first victim is a salvaged and shelfed engine so who knows when it'll blow anyway. I already know that it rattles if I shake it and 13B's shouldn't rattle...lol...

The next one will be ported and propperly tuned to make peak power just under 10k...high up, but still quite broad power band. 2nd and 3rd gears will run forever. Anyone good enough with math to tell us what 3rd gear is in an GTUs at 9450? That's where my buddy's S5 limited...it was sick...

Also, neither of you could have ever heard a 9k+ 13b screaming along...
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Old Sep 13, 2005 | 12:29 AM
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My high compression streetported turbo is limited by the ignition system at this point. In third gear above 6.5k I get really bad breakup. It really sucks. I'm making power past the limiter and I can't even take it past 6.5 in the high gears. I have hit the limiter in second a couple times just becuase it keeps pulling up to 7.5..... who knows how long it would pull if the limiter wasn't there. My Goal is a large streetport and standalone plus some s5 N/A rotors bringing my usable power band up to 8-8.5k rpms. More than that just scares me.
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Old Sep 13, 2005 | 12:35 AM
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turbos work different. To get higher numbers from an N/A you need either lots of displacement or lots of RPM. Of course, certain things remain exceptions to those two requirements, but, in general, that's how it is.
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Old Sep 13, 2005 | 12:35 AM
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Originally Posted by 13bpower
My high compression streetported turbo is limited by the ignition system at this point. In third gear above 6.5k I get really bad breakup. It really sucks. I'm making power past the limiter and I can't even take it past 6.5 in the high gears. I have hit the limiter in second a couple times just becuase it keeps pulling up to 7.5..... who knows how long it would pull if the limiter wasn't there. My Goal is a large streetport and standalone plus some s5 N/A rotors bringing my usable power band up to 8-8.5k rpms. More than that just scares me.
Will the R-tek and RA apex springs be able to take it?

(lol)
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Old Sep 13, 2005 | 12:41 AM
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Originally Posted by eriksseven
Will the R-tek and RA apex springs be able to take it?

(lol)
Ohh! we know the atkins seals wouldn't be able to! How is the seach for new rotors, housings, and plates working out for ya? Sucks those atkins seals didn't stay in there place.

Come on Erik, you gotta read the whole post. I would be doing that on a standalone!

PS: Erik is a noobah!
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Old Sep 13, 2005 | 12:46 AM
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Originally Posted by 13bpower
Ohh! we know the atkins seals wouldn't be able to! How is the seach for new rotors, housings, and plates working out for ya? Sucks those atkins seals didn't stay in there place.

Come on Erik, you gotta read the whole post. I would be doing that on a standalone!

PS: Erik is a noobah!
hahahaaha,

I worked out a deal with some dude in Oregon for my blown Greddy Type-S (got a new one) and $200, for a coolant seal failure TII block with 100k miles.

LOL, I think your RA springs are going to flatten... hahahaha.

Word to your motha' on the standalone.

(back to topic)
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