I've seen in several of Rob's WOO-HOO threads the mention of stiffer springs making more power, with increased boost, than the stock ones. I have a Magnum Powers blower case with stock heads. What kind of gains should I expect with a 6 lb. lower pulley and the 2.7 upper with long tube headers? Lets say after installing 112# springs? I'm thinking the stock heads and cams may be capable of more power than we're currently seeing out of them. I'm on a stock block and will probably never be a weekend warrior at the local track; but, floating the valves under WOT doesn't sound like something I want to be doing either.

 

some correct me if im wrong here..

But the reason for the stiffer springs is because a new cam is used. The stock springs are made to handle the pressures a cam will put on them

 

Do you have a dyno graph to look at you can post. If you see a drop off like me and Rob had then more than likely your losing power. If you dont then you probably arent in that range yet. Post a graph.
Jason

 

I'm not making the power you guys are; but, I do have a fall off of power at about 4800 rpms. This dyno was before I installed the 60# injectors and e-fan. Different tune as well. The graph shape shouldn't have been changed though.





Yes, I know that was a lean pull. Hence the 60lb. injectors and updated tune.

 

I think Charles dynoed in the neighborhood of 30 hp with a 95lb spring and it showed signs of needing more spring. Also remember that the intake is were the big problem lies in a S/C motor. You really don't need a lot of spring on the exhaust side, although it wouldn't hurt to bump the stock spring pressure up to 75 lbs or so on the exhaust side. Turbo is different...way different.
Dale

 

Please explain what is so different about a Turbo compared to a S/C for valve springs.

Thanks Driven

 

An S/C engine has higher than normal pressures in the intake tract only...A turbo has higher than normal pressures in both the intake and exhaust. There is more to it than that but thats as far as I need to go
Dale

 

at what point (if ever) does coil bind come into play?

after shimming, what's the next weak link in the valve train?

 

Coil bind shouldn't be an issue unless you are running some serious lift cam. Or massive shims.

 

Those weak *** push rods that ford uses in these lightning!!!!

 

Don, that just shows how much you know. Not one person has broken a pushrod in a genII I think they are strong enough!

 

Thanks for the reply that makes sense to me.

Driven

 

Odin. I had this conversation with Charles and he mentioned that the factory springs in our trucks are barely adequent for the 8-10 # that they produce and when going up to higher boost levels, especially with the M/P , a 110# like crower's stage 2 or even the stage 3 springs are what is needed. According to him and the other tuners, this is a highly overlooked issue.

 

I'm wondering if we have the same springs as the N/A 5.4's? If so, I can definitely see where that would be an area to focus on. I'm surprised it hasn't been an issue more widely discussed here over the years. Being a novice, it never occured to me. I'm interested to see what kind of gains are possible in the upper rpm range, on a stock long block.

 

to see a stock long block truck with a say a 6lb lower, and open air intake dyno'd back to back with no change except valve springs. The odds of it happening are slim to never.