Weak Valve spring Symptoms

[Hognose]

What some symptoms of weak valve springs? I am curious because My car is not making power as I go done the track. I am only gaining 17 mph in the second 1/4 mile.

Just got back from 1/8 mile track and am running great 1.8 60fts bot only getting 79mph. This is at 23lbs of boost too.


Could week valve springs make that much of a differance on the top end? Could they cause a rich condition? I am running rich even with 39lbs of fp and pulling fuel out of the chip at WOT.

Just switched to brand new 50lb injectors the other day and ran slower than with the 42.5.

Any help would be great. Thanks

Matthew

 

[UNGN]

I'd put my money on your non-lock up converter being your real problem, but Valve springs are easy to diagnose:

Check your RPM's with a scan tool as you are going down the track.

If 100 mph = 4400-4600 RPM its the valve springs

If 100 mph = 5000-5200 RPM its the converter


Being Pig Rich will kill top end, too, so you may want a better chip (be sure it isn't cutting all the timing in 3rd).

 

[Hognose]

I can barely reach 100mph in the 1/4!!!!

If I remeber though I was not that high of RPM when I was at the 1/4 mile track a couple of weeks ago.

Chip is a brand new Turbo Tweak. I was having a rich condition with my 42.5 inj. Hadd all the fuel pulled out of the chip and had the fp down as low as it would go. Just put these new 50's in and with the fp at 39 lbs my 02's are still in the 820's in 3rd gear.

I would think that with my set up I should be quicker than I am even with the non lock up convertor.

Thanks

any other suggestions? FPR is new also.

 

[trbojo]

my weak springs were causing a sputter right before the 1-2 shift. basically a higher rpm sputter.

 

[Hognose]

Could it be possible that my I have a a broken valve spring or two? I spoke with the previous owner of the car, who is a board members brother, and he had gone 8.7 in the 1/8 @ 90mph. Plus he was only running 15lbs of boost!

Everything sounds fine with the motor. All my fuel delivery has been replaced. I am thinking that as the rpms of the motor rise I am actually losing power. Off the line it is great. I had a 1.76 short time last week. That is with BFG Drag radials with 30lbs of air in them!! It seems to me that if the valves are not operating correctly that they will be even more inefficient as the rpms go higher?

I put a vaccum gauge on the car and the needle is steady, so I don't think I have a wiped cam.

Any other suggestions? Thanks

Matthew

 

[WHEEZER]

In my opinion you may not be as far off as you think, not saying you don't have a problem, typical ballpark mph difference between 1/8 and 1/4 mile times should be about 20 mph with your combo. It's all about the tune. You're not manually shifting, right?

 

[Hognose]

I am not manually shifting. I should mention that when the previous owner was at the track, the car was in bad shape, only running 15lbs of boost with a bad boost solenoid. A tranny that flared the 2-3 shift also. and the SES light on.

I know that I am probably losing a couple mph from my non-lockup. Peviously it had a lock up. But 10mph in the 1/8 from that? I know my tune isn't that off. Plus I am running 8m ore lbs of boost, he had a 2.0 short time on street tires. I am cutting a 1.76 to a 1.84 60ft.

Here are my 1/4 mile times

60ft.=1.89
330=5.336
1/8=8.291@83.06
1000=10.867
1/4=13.066@100.97

Thanks,
Matthew

 

[WHEEZER]

UNGN may have nailed it. I really would try his suggestions, especially on the chip. One word...TurboTweak.

 

[Hognose]

Originally posted by WHEEZER
UNGN may have nailed it. I really would try his suggestions, especially on the chip. One word...TurboTweak.

Thanks, but I had mentioned earlier that it is a brand new turbotweak chip. I am almost positive that I was no way near 5k when I crossed the line at the 1/4 mile.