Pac 1218's and a TU2

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Jan 12, 2014 | 11:12 PM

jt76

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Pac 1218's and a TU2

Quick question before I purchase..

Budget build for my '95 mustang. stock 6.0L/S480/ Speed inc Tu2 cam… will these springs suffice? They are rated to .600 and the tu2 is in the .580's.. not sure if throwing boost at this is going to make the 1218's a no go. What say you LS1tech?

Jan 12, 2014 | 11:56 PM

5.slow99

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they should be fine. i assume you probably will not be daily driving it anyway though

Jan 13, 2014 | 12:50 AM

GMCtrk

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I had a 1218 snap on my boosted setup, similar cam. Now with Tooley Platinums.

Jan 13, 2014 | 06:07 PM

jt76

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Quote:

Originally Posted by 5.slow99

they should be fine. i assume you probably will not be daily driving it anyway though

Yeah, maybe a couple days a week just messing around

Quote:

Originally Posted by GMCtrk

I had a 1218 snap on my boosted setup, similar cam. Now with Tooley Platinums.

Did they work well or is that why you upgraded?

Jan 14, 2014 | 01:41 AM

yonerhottlt1

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If it was my build I would still upgrade to some dual .650 lift springs for insurance. Even if nothing breaks you're still risking valve float with the turbo setup.

Jan 14, 2014 | 07:07 AM

hellbents10

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Turbo will not make it prone to valve float, boost has almost zero impact on spring pressures. I have run the 1218s with similar lobes to 800rwhp.

Jan 14, 2014 | 09:45 AM

THADD

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Seat pressure is what's important with boost. If you don't have enough the valve can hang open. We have seen this problem with a 76mm starting around 15 psi. It would make 800 or so until that point, after that it would go down hill and show it was rich

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Jan 14, 2014 | 01:56 PM

hellbents10

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There is a lot going on the other side of the valve. I never had an issue with 130 on the seat at 6500 rpm with the correct turbo???

Jan 14, 2014 | 03:55 PM

#10

qqwqeqwrqwqtq

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Quote:

Originally Posted by hellbents10

There is a lot going on the other side of the valve. I never had an issue with 130 on the seat at 6500 rpm with the correct turbo???

I suppose correct depends on the goal.

A lot of the stuff that can hit peak boost/torque early is going to have some backpressure.

On the intake side you are of course starting the compression cycle at IVC.

On the exhaust side you may see double the pressure you see at the intake and at EVC you'll get valve bounce. (and it noses over hard).

I wouldn't personally set up any turbo LS with 130 on the seat but that's just my opinion