RB27 Tuning Update! Need Help.... Issues stilll...

[Shocker]

lol Matt, I'm hungry too thankfully work has snacks. Combo Pizziaries ftw!

thanks Eikon, rb20 sounds mean! ahah

Drag, as long as Saturday goes smooth and we finish the tune, hopefully in a couple of weeks! My ****ing transmission is acting up.. I might need to go back to heavy shock proof....

I'll be sure to update with info and time's! I just want traps really for now...

[rb25drag]

ouch transmission problems is all you need!! Well if it comes down to it, Swap a t56 6 speed in place

[Shocker]

ouch transmission problems is all you need!! Well if it comes down to it, Swap a t56 6 speed in place

id do a 6 speed Getrag before that.

If transmission goes I'll either rebuild the gears, and get a billet shifter plate for 3rd made, of source a good used one...

I didn't do this 2 years ago, I was running a heavy/light mix, this time its all light. I just had all the brass replaced to by a buddy of mine who owns a shop..... he SAYS he did it all right, and one gear had a little wear on it... but It ground hard into 3rd last night, and at low speeds/rpm it grinds 4th...... GAY.

Yeah clutch is bled, and I know how to drive..... lol

[Shocker]

****UPDATE!!****

Well it appears as if my ***-Dyno is off by over 50%. We got back on the dyno today, only to see my issue did not go away. The boost leak fixed spool times and response, but didn't fix ANY numbers...

We are making 200ft-lbs at 2000 and at 4000 with 14 psi. Fuel pressure is all straightened out now. Holding 45psi vac off at idle. Didn't change at all day. The car just has no balls. Dont get me wrong, its not slow, but its no where near what it should be.

Everything is basically perfect. Air intake temps, water temps, a/f ratio (11.1-11.3 at WOT), timing is spot on as well, plugs are great, good equal burn pattern and no missing...

I drove down with my buddy who owns and EVO 8, my car is basically as fast as his bolt on EVO.... to give you an idea, but its making numbers of what it should be.

We really are thinking that its something with the valves/lifters/springs.

Springs possibly weak and when boosting begins they start leaking at the intake ports that are supposed to be closed. (so the back of the closed valve stem is being pressed down by the 14-15 psi in the plenum)... even if it is just a little bit, its enough...

Or I have some bad lifters, but I'm doubting that since we have no lifter tick. Even this morning I turned my car on it was 32 degrees outside and no tick....

opinions would be greatly appreciated. As nice as it is to drive my car now, I feel like I have wasted xx,xxx dollars just to make it as fast as it was before...

The head I'm using is not my old head but rather someone elses...so I'll I know about it is that the valves hold cylinder pressure... but I don't know about boost...

-Cory

[Carl H]

what does your timing map look like?

[240z4u]

what does your timing map look like?

I agree with Carl, there is a ton of hp in timing... you did say that it was lighting your manifold up pretty well before. Seems like you needed more timing.

Also, are you running adjustable cam gears, and are you sure they are dialed in precisely?

Good luck dude.

Evan

[sil_eightyRPS13]

i do not make any tq or power till 5000 so dont feel left out...lolhttp://members.shaw.ca/sil_eighty/dynosheet.jpg

[Shocker]

I agree with Carl, there is a ton of hp in timing... you did say that it was lighting your manifold up pretty well before. Seems like you needed more timing.

Also, are you running adjustable cam gears, and are you sure they are dialed in precisely?

Good luck dude.

Evan

Thats a thought, BUT, we were making huge numbers before.... with the same boost pressure, we even added more timing in yesterday, and still nothing.

Cam "gear" is in stock location we didn't touch it yet.

Before we were looking at 300ftlbs @3k now we are at 200ftlbs@3k.... same boost pressure same everything and even now there is MORE timing.

Everything went great until the run when we put down 387hp and 345ftlbs@5500 rpms last weekend. Thats whats making me think something let loose in the head? I'm going to inspect under my valve covers in a little bit.

[Shocker]

I just removed the valve covers and inspected the hydro lifters, none are squishy, all are solid as could be...

I've been reading up on tomei's site about valve springs, I might ordering a set tomorrow....

[240z4u]

Cool, I was just wondering if one of your cam gears had slipped or anything like that. Just throwing out random and far fetched possibilities! lol

So are you thinking valve float basically?

Evan

[Shocker]

Cool, I was just wondering if one of your cam gears had slipped or anything like that. Just throwing out random and far fetched possibilities! lol

So are you thinking valve float basically?

Evan

yeah something along those lines.

I'm going to call a few experts tomorrow to get a second opinion hopefully I can find some answers....

[Darius]

What exactly causes valve float? I thought it was when the rpms were higher than the valve spring could keep up with and the valve ended up staying open.

[Shocker]

What exactly causes valve float? I thought it was when the rpms were higher than the valve spring could keep up with and the valve ended up staying open.

yeah Kinda like that.

We are thinking more along the lines of weak and fatigued valve springs... Cause this issue came about right as we started to make some bigger numbers= more stress. Maybe it was just to much for them?

I think I'll be upgrading to Tomei springs anyways.. 1 it will eliminate one option for issues, 2 it will provide better in the long run when taking her to 8k.

I'm still open to more opinions on where the power vanished too. lol Don't forget, leak down is perfect basically....95-100%...

[ItzGenX]

Cool, I was just wondering if one of your cam gears had slipped or anything like that. Just throwing out random and far fetched possibilities! lol

So are you thinking valve float basically?

Evan

It isn't as far fetched as one might think. If his leak down numbers are 'perfect', then that's one of the things I would look into first. I would not consider valve float from fatigue springs because they do not fatigue like an on off switch (high power dyno, then suddenly poop). If they do this, they tend to break the spring instead. Also, if the springs are THAT weak at low/mid rpm to not even hold a valve closed with 12-14psi, the problem should get exponentially worse as the rpm go up. We are talking about 100ft/lb of torque lost at 3000rpm. That is 33% less then what it was. To cause a huge number difference like that and not be the fault of the tune or fuel, I would be looking into valve timing, especially if they still have perfect leak down. One tooth off on a cam can cause night and day differences in how the engine runs.

[Disturbe240]

It isn't as far fetched as one might think. If his leak down numbers are 'perfect', then that's one of the things I would look into first. I would not consider valve float from fatigue springs because they do not fatigue like an on off switch (high power dyno, then suddenly poop). If they do this, they tend to break the spring instead. Also, if the springs are THAT weak at low/mid rpm to not even hold a valve closed with 12-14psi, the problem should get exponentially worse as the rpm go up. We are talking about 100ft/lb of torque lost at 3000rpm. That is 33% less then what it was. To cause a huge number difference like that and not be the fault of the tune or fuel, I would be looking into valve timing, especially if they still have perfect leak down. One tooth off on a cam can cause night and day differences in how the engine runs.

x2

[Coolwhip]

Yea, degreeing those cams and engine will make sure its dead nuts since you are now working with a built engine.

Cory, email me, I can help you out on some of those endeavors

[johnzm]

if your gung ho about your lifters, check the pad clearence on them with motor cold/hot.

id also doa leakdown and verify timing.

could have melted something slightly in there on that last pull

by the way, what lift/duration cams u got in there right now???

[Shocker]

ItzGenX. I ****ING LOVE YOU.

I WAS ****ING OWNED.



I cannot ****ing believe this ****, the bolts got pulled over on that power pull causing MAJOR exhaust retardation, thus all my power going to the ****ter......

thank you guys SO MUCH! for all the help, it appears this is my problem, and its time to go back down and finish the tune.

What a relief, I would have shot myself If I tore apart my head for nothing only to find out it was this stupid *** gear......

I'm leaving it how it is, and when I get back down there to re-tune we will loctite and clamp the **** outta those stupid bolts.

-Cory

[Coolwhip]

Thanks for allowing the opportunity for this to be used.

[mott6904]

perfect time to degree your cams

[Shocker]

Thanks for allowing the opportunity for this to be used.

ahh Ricky, how I love the comedy, and I'm not sure if you provided anything other than popcorn to this thread.

I did however just finish a nice bag of Orville Reddenbauchers Pour Over cheese popcorn omg was it a treat.

I will sleep much easier tonight.

[l0nestar]

Shocker,I did not get to read this thread over the weekend, but after I began reading it this morning, I started thinking to myself

'I wonder if his cam gear had slipped a tooth, no. Shocker had adjustable cam gears , now, I wonder if an adjustable gear had slipped, or loosened up... and timing was gone on one of the shafts. '

Then I see that is what happened! Agreed that pulling your head to discover it was the gear that slipped would.. suck. Congrats on finding the 'culprit'. NOW GET WITH THE CHARTS AND VIDEOS!!!

Ricky,Congrats on being able to use the baby-fail image again!

ItzGenX,I also would agree about the valve springs being ruled out because they would just.. fail. Or azz-plode or in general, quit working properly.

[Shocker]

Lonestar, yeah what clicked for me was when he said it sounds like timing is off a tooth....

I was about to respond with NO its not lmao, then I thought of my stupid EX cam gear.

What a relief for sure, I'm very excited to see the finished numbers. We were making much bigger numbers that day than I could have hoped for....

I'll be sure to update, hopefully I can get back on the dyno end of the week.

[Darius]

...double check the mechanical timing...

This was from my first post on page 1 of this thread.

Glad to hear it was something minor and free. Now get that b**** tuned!

[matafied]

now your going to lose sleep anyways from anticipation!! Just think you put down 387hp and 345ftlbs@5500 rpms with a boost leak and a gradual slipping cam gear and now you have to wait till the end of the week can't wait to see the #'s Shocker

[Shocker]

This was from my first post on page 1 of this thread.

Glad to hear it was something minor and free. Now get that b**** tuned!

yeah yeah, I suppose If I had two cookies you'd get the other Matt.

Matafied, don't forget that was only 14 psi as well.

[Darius]

Sweet! I like cookies! Girl Scout S'moas FTW! Know what else I like? More videos

[Shocker]

Sweet! I like cookies! Girl Scout S'moas FTW! Know what else I like? More videos

lol, hopefully this weekend!! As long as it doesn't rain when I'm supposed to tune, (dyna-pacs dont like to get wet - p******....)

[Shocker]

Well... heh... looks like no dyno-day friday for me.

Was changing bolts out today for my cam gear to hex caps instead of allen... and well started the car up, and heard this grinding ish noise, kinda like a bench grinder taking care of a little piece of metal, not to loud, but notice able...

I figured it was with something I was just doing... but nope, under closer inspection it was coming from my turbo....... yeah..... so I shut the car off, and listen to the grinding noise still take place until the turbo came to a rest about 30 seconds later... I checked shaft play, and there is enough for me to touch the compressor housing just barely with the tip of a blade.... WTF.

This turbo has ****ing 500 miles on it.......... I got it through AMS, its a garrett core with precision housings.... I cannot believe this ****. Its got proper oil and coolant going to it.....only being pushed 14 psi, and being reved to 5500....

I'll be calling them tomorrow, I really hope they can do something about it, this ****ing sucks I just looked at the bill. It was 1628.50 for this sucker.... Thats my car when I first bought it........

Oh yeah this just started this afternoon, the noise was not there this morning when I started the car because I was checking over the engine bay before I left for work.....

this sucks....

[mott6904]

Damn what a biatch. It seems like with rbs it always one thing after another. Cant wait to see the new videos and numbers.