What are new valve springs worth? HP?

[lil_v6]

My car has 98,000 on it. Motor is still stock. Car runs 12:20's. If I was to replace the valve springs, what kind of difference would I notice, if any? What is the average gain?

I am running 22 lbs of boost w/alky.

 

[John Pearcy]

It's not really a matter of how much HP increase you'll get, but rather returning the car to it's former glory. The stock springs are rated 90Lbs (+-5Lbs) but will never hold their rating due to poor material. I tore down a 5K mile motor to discover only 63 Lbs, this gives you an idea how bad the stock springs are, buick used them because they were a carry over exsisting part which was designed for quite operation.

Once you upgrade the springs, (100 Lb most common) you'll notice instantly the engine will continue to "PULL" and eliminate the nosing over feel you have now. Ever notice how much harder your engine pulls when the next gear is hit? Your car runs out of steam well before the top of the gears right now, the new springs make the engine pull HARD regardless of RPM's because now the valves are not floating.

Change the springs and be VERY happy.

 

[Momar]

Where is everyone getting the new springs? How much are they. My car has about 110,000 on it, and definately has that nosing over feeling. I also noticed how it picked up when it hit the next gear.

Ben

 

[91Bird305]

I bought my springs for my 87 GN engine from www.johnsperformance.com Pretty good deals and quick shipping.

 

[NCTURBOS]

CompCams 980-12 is what I use on cars with the stock cam. I have seen multiple cars pick up mph with this change due to what John lists above. Most Comp vendors have these for less than $50.00


K.

 

[tpabayflyer]

I bought my springs at johnsperformance and they were pretty resasonable at around $50 or something like that... I also bought a bunch of other items from John recently and would recommend him. TBF

 

[dan lephart]

spring

comp cam 980 from jeggs $50.

 

[D's GN]

Has anyone done a before and after valve spring change comparision in regards to 1/4 mile vs mph? My car just went 12.30 at 108 and feels like its nosing over and won't rev past 4000, hopefully I can go 11.99 after the change

 

[Unsafe6]

The 980's are $38.69 at Summit but it says the spring rate is 302lbs/in?

 

[JDSfastGN]

Originally posted by 87GN_D
Has anyone done a before and after valve spring change comparision in regards to 1/4 mile vs mph? My car just went 12.30 at 108 and feels like its nosing over and won't rev past 4000, hopefully I can go 11.99 after the change

i would really think that you could pick up a whole lotta ET and mph with your combo if its tuned right. That 61 should trap 115 at anything over 21 psi, so its a possibilty they are holding you back as a 61 should really come alive after 4 grand.

 

[D's GN]

That is what I was hoping to hear It was my first time at the track and was stuck with the notion that if you have no knock and are running somewhat low 02's that is where you get the most out of your motor. Do I trust the scanbastard? it was telling me I was at a low of 750 02's, do I pump up the fuel pressure say 2-3 #? Boost was 23-24psi with alky. Everybody is telling me I should mph higher....maybe valve springs, shifting at 5200-5500 vs 4000 and locking converter may help?

 

[dsa87gn]

Regarding spring health based on 1/8th to 1/4 ET's and MPH

My first time to the track with original springs yielded basically
1/8ET * 1.53 = 1/4ET
1/8MPH * 1.25 = 1/4MPH

Is changing springs going to do anything for me other than greasing me up for a couple hours ?

 

[John Pearcy]

Originally posted by tpabayflyer
I bought my springs at johnsperformance and they were pretty resasonable at around $50 or something like that... I also bought a bunch of other items from John recently and would recommend him. TBF

No, I only charge $40.00 for the springs.

 

[87GN_70GS]

The standard replacement spring is Federal-Mogul or Sealed-Power VS677 or VS744. The VS 677 is $1.69 ea from summit, 3.13 ea from advance, or 2.49 from napa. A set of 12 from summit is $20.

The "Z28" or "LT-1" or 100 lb spring is VS739R. It is $2.25 from summit, 3.09 from advance, or 2.69 from napa. A set of 12 from summit is $27.

 

[microELVIS]

I have to add, dont do them yourself unless you have the right tool to remove them. The back passenger side spring is hard to remove without the special spring removal tool, I dont care what anyone says.

 

[Momar]

Which type of spring removal tool should I use. I have access to a couple types.

Ben