Have people used these with good luck?? I need a replacement for my #918's that I'm sending back. I really want to stay with the beehive design as I have all the other new parts that I don't want to replace. Thanks

 

I myself haven't heard of a PAC failure. It seems like once a week I read on here about the 918 breaking. After I has 8 break I went with a dual.

 

they are a better spring than the comps,IMO...

 

The PAC 1518 is the 'original' Comp 918 before they went to a new manufacturer. They have had nothing but problems since moving away from the PAC spring.

The PAC 1518 is a great beehive spring.

 

How come they rate the .600 lift PACs at 318 lbs open at 1.200...but they rate the .650 PACs at 337 lbs open at 1.150? Wouldn'y the .650 lift springs have nearly the same open pressure at 1.200? That would mean the spring rate is the same...so what's the difference between them other than the price?

 

I think it is the Nitriding that makes the difference.

I have the PAC 1520's going on my AllPros for my 455, nice and light.

 

According to the specs, they both have a rate of 313. One difference is the 1518 is nitrided and the 1218 is not, not sure if there is anything else different between them.

 

Thanks for the feedback guy's!!

 

pac 1218 working fine here

 

If they are given u the new revised 918 in place of your older 918 then u are fine.
They are now polished and have a different finish process and are good to .625...

If u are afraid to run the revised 918 then go Pac 1518 or PSI 1511
U wont find a better beehive then the 2 of these springs and there both rated to .650

 

Thats pretty much it, I would like to stay with the revised 26918's, but I don't trust them. I called PAC today and there #1218"s are all sold out. (wonder why) So I have a set on order as soon as they come in. I have a fairly mild cam @.571-.573 so these should do.

 

1218 is all u will need with that cam but honestly the revised 918 if u get them free are fine.....

 

We Have PAC 1218, 1518 and 1221 springs in stock
http://www.ls1speed.com/cont.cfm?cid=C0000794

We swap camshafts on Fbodys, C5/C6 TBSS, GTO at a rate of 1 to 2 per day, we've installed many sets of these springs with 100% reliability over the course of 1 year now, that means alot to us.

Even though a spring failure may not be installers error, it still leaves a bad mind set for the customer that you were last to touch the car, so we like to avoid that.

Many of our customers daily drive their car with a 224/224 or SI5 cam and cold starts arn't something a race car may experience. The PAC springs are up to the job.

 

I think they're great

Seriously though, hit up Speed Inc. if you need some. Probably cheaper then direct (hey it's the truth). We'll have some more on the shelf very shortly.

 

Ordered some this AM from Frazer @Speed Inc.