Best of 3 runs showed a gain of 4rwhp and a loss of 8rwtq accross the board from my last results in my sig.

Same dyno (dynolab) both corrected. Last dyno was in Nov and this one was last thursday.

EDIT

Here is the weather history in Nov 2004 when I had the first dyno. 58.7 °F and 83% humidity at 12 noon.

Here is the weather history for July, 2005 76.5 °F and 80% humidity at 2100hrs

Pretty damm disappointed with the results. Its nice to have strong parts in there but for $1000 a gain would of been nice.

Will try and post the graph later tonight.

So am I going to have to drive to LA so that Alan Futral can get my torque back with a tune?

 

Dude - you expected some serious gains from just rockers ? (springs are hardly a power mod anyways)
And now you're gonna pay $300+ for tune to get the lousy 8 rwtq back ???

You're silly ! :-)

 

I hear you on the tune. Not going to do it, unless Alan comes to the atl again.

Not serious gains but I would of been happy with a TQ gain and a few HP loss.

I know no gains from the springs and retainers, just wanted to list the mods done.

these where the 1.8s

 

Are these the quick lift rockers?

 

Hey I will be in Atlanta all next week on business. I have HPTuner for 2001 Vettes. If you would like me to scan a couple of WOT runs and maybe adjust your WOT (PE) AFRs I would be more than happy to help.

We (a couple of PSP guys) are installing an adjustable timing set on my C5 also...

Just let me know... it is quick, easy and most importantly FREE.

 

Yes.

 

Thanks!!! Interested will send a PM.

 

I too am disappointed as this is not what I was expecting based on all my reading on the Cranes to date. Any differences in conditions between your last dyno run and this one (tires, etc.)? Have you spoke to Vinci at all on this?

 

Same dyno (dynolab in Atlanta) last time was in Nov as per my sig. So hotter and more humid now, but if its corrected that should not make a difference, right? Car has new plugs TR55 coppers, same plug just new. Same intake.

Had the car out this past w/e for some "hard driving" and all was well.

Putting graph in orig post.

 

DUDE!!!! You have lost power everywhere except 6000rpms. We will get some goods logs recorded and see if anything sticks outs (KR, too rich, etc). My gut feeling is that Tony is right... I have read about it too many times on this forum...

I am staying at Mike F. house so we can hook-up Wednesday right after work...

 

I know Tony is the man, but if I got me some valve float with ti retainers I ain't gonna be happy.

Looking fwd to getting a look at WTF is going on next week.

Thanks again!!!

 

As Tony stated, you sometimes have to do some experimentation when using roller rockers before you hit the right combination.

I lost a little peak power and had a wicked power dip in my dyno graph at ~5900 rpm when I first installed my Crane 1.80 Quick-Lift roller rockers. A change of valve springs (to the Crane duals) and slightly shorter pushrods eliminated the harmonics causing the valve float, made the power dip disappear, and my loss became a gain of 10 rwhp and 8 rwtq over the SLP 1.85 rockers I replaced.

 

P.S.- I was using titanium retainers during and after the loss. The harmonics kicked my power's *** at 5900 rpm anyway until I swapped valve springs.

 

My car felt a bit slower on the top end since instaling Yella Tera rocker arms, so I just took them off. Didn't feel like spending more time/money swapping out springs just to get the rocker arms right, and didn't want to mess with getting custom lengh pusshrods. Since yours cost you twice as much as what the Yella Teras cost me, you might as well try what Xtrooper and the others told you. Good luck.

 

Its funny how some people report gains with these rockers and then when someone has problems with them, you find out that some had to change parts to make them work right.

It would of been nice to know this stuff before hand.

Oh freakin well.

 

Do a search of my name. I gave the full story of my experience from the get-go.

 

My I step in here? Let's take one thing at a time. Your baseline dyno runs were in November right? A lot can happen in 8 months, especially to a performance engine. If I remember correctly, you broke a spring on your car. At this point, the integrity of the engine is suspect i.e. compression, internal damage,etc. The vehicle should have been dyno tested right before the rocker install to be at all credible. That being said, Georgia is hot and wet in the July and dry and cold in November. Your graph does not show any weather information. I can tell you, having run a Dynojet for ten years in Florida weather, one can never expect to regain the losses produced by bad weather conditions from the SAE correction factor provided by the Dynojet software. It stinks but it's a fact and we have to deal with it everyday. We always re-baseline a vehicle before a major modification and re-test in the same atmosphere after the install for accuracy and validity. Serious testing requires some control over the variables. We have installed hundereds of sets of these rockers with pretty much the same gains for over six years. We rarely hear anything negative from folks who are using them if the rockers were properly installed. We have had to re-adjust some rockers, in accordance with our strict instructions when performance issues have risen. Some installers take the install process lightly and the adjustment depth of the lifter plunger is compromised. Tony Mamo just said he uses the Crane rocker kit on his own C5. I value his experience and his opinion. I take exception, however, to his comment that Crane rockers may be too heavy and therefore induce valve float. The Crane rocker weighs 142 grams. The stock rocker weighs 137 grams. That is only 5 grams difference. Not much of an issue with a rocker arm, could be an issue if you deal in illegal substances lol. The increased weight is located primarily over the rocker stud. Furthermore, the moment of inertia is less with the Crane rocker. Another benefit is the extra leverage provided by the increased rocker ratio allows the use of lower seat pressures to control the lifter as it returns to the base circle and to control hydraulic pump-up of the lifter's inner plunger. The advantages are significant and evident and we have continually observed this during the vast amount of dyno testing we have done. Perhaps Tony was refering to the "other" aftermarket rockers. Regards, Roger Vinci. P.S. PM Joe Vinci so he can try to help you get the car back on track

 

Are you suggesting that there might be too much preload on the lifters?

 

When I asked if someone had installed them you replied:

https://ls1tech.com/forums/showthrea...=crane+rockers

Also in this post you talk about your install of the crane rockers:

https://ls1tech.com/forums/showthrea...t=crane+rocker

No where did I see you talk about having to replace the pushrods with shorter ones till this thread.

You talked about using cranes dual springs which I have done from the start.

 

Damm thats a long paragraph sir.

I can understand that a "correction factor" can't make up for a dyno friendly day in Nov vs a hot day in July. I'm guessing the only way we are going to know for sure on that is to wait 5 months.

With the dual springs we waited 8-10 mins between each 1/4 turn adjustment.

Also I replaced the broken spring with these, I was not going to install a set of stock springs, redyno then install your product then redyno again. I don't have the time and money for that.....