str8dum1

iTrader: (11)

Hey guys,

my blower will be back from vortech shortly and I want to get 'er back up and running.

Its been a little bit of time since my dyno tune and I am having trouble remembering all the details about the graph. The 370/330 is mine and the other one is a "normal" Vortech graph where you can see steady torque with increasing power to redline. Mine, increases to ~5700. Then the power stays the same but the torque falls WAY off.

Obviously I have problems after 5700 rpms. Its was suggested that I had a boost leak and that the boost leak was causing knocking. Something along the lines of the leak causing the blower to work harder and heat up the air causing knock.

I might have that explanation incorrect though as being my 1st dyno day etc, excitement was high and ears were on low.

But, how can the blower work harder when its directly attached to the motor? Also, wouldnt a boost leak cause a rich condition, the opposite of what would cause knock? I would assume that the timing params are optimal as the tuner knows his stuff. What else could cause knocking at high rpms?? I assume, that if there was alot of knocking above 6000 rpms, the tuning might have backed off timing which would show as a lower torque??

I tried to find dynos of other Vortechs with boost leaks, but was unable to. From what I have read, if it was belt slippage, the boost just levels out. BUT, would you see a -50 ftlb drop in torque? Same question goes for a boost leak, why would there be such a significant drop in torque. If the boost was just bleeding, shouldnt it just hold steady?

I didnt re-gap my new 1 step colder plugs when i installed them, assuming that the stock gap was fine. If a plug was misfiring, how would that show up on the dyno? How would that be seen by the UTEC? I never threw any CEL codes related to misfire, so i dont think thats a problem.

Sorry for the novel, but i wanted to make sure I was detailed as possible.

Thanks!!

booger

iTrader: (6)

There is just to many possibilities of what your problems may be . The only way is to take it to a shop and have them go thru the car . Look at the tune and go from there . Any one on this forum can only guess at what it can be .

str8dum1

iTrader: (11)

guess are fine, bc they can be used as starting points. the shop was uninterested in troubleshooting as I did the install myself.

i guess the main question would be, is that dyno representative to what a boost leak would look like in terms of both HP and torque? Thats what I cannot find examples of to compare to.

booger

iTrader: (6)

And it would probably be hard to find an example of a boost leak on a dyno . I believe I told you how to make a pipe with an air compressor fitting to hook up to your IC pipe just before the BOV . Then cap off the exhaust and find the leak if any . There may have been a lot timing pulled up top . There may have been to much fuel added . Your belt maybe slipping up top . Just a lot of guessing

str8dum1

iTrader: (11)

when i searched boost leak, 17 pages popped up, so its not an "uncommon" issue.. Basically everyone just assumed they had a boost leak bc they werent reaching their "expected" boost values.

A quick look at my UTEC tables would show if timing or fuel was added or pulled though right? I just dont want to drive way out to a tuner again, only to have over looked something, hence the general questions.

so you keep the BPV as part of the pressure test?

either way, i'm not looking for someone to fix my car, but more general bits of info about the way the charts should look under difference circumstances.

Audible Mayhem

iTrader: (48)

hey there, here is an overlay of a few graphs. yours is in the middle. the lowest one is a revup with a 2.87 pulley.

the top one is a graph of your exact same setup that we tuned a few days ago.

this was done here at Performance Factory and made some crazy power!!

im sure you will find something stupid with your setup that makes sense why it doesnt make full power. good luck on figuring it out, shouldnt be hard to do...

thanks!!

str8dum1

iTrader: (11)

Thats awesome power. Gotta be one of the top 5 SC dynos. I pm'd you some specific questions about the tune.

DO you have any graphs of belt slip? Does torque nose dive under belt slip as well?
Mechanically i know what i tightened, replaced, moved etc. I can do boost/vacuum checks. But without knowing what was done with tune, like Booger said, it could be any # of other things wrong with the car besides the installation of the blower.

thats what prompted me to repost, to try to pick some brains about "other" things to check that might be assumed info to some, but alternative avenues to recheck nonetheless.

thanks!

Audible Mayhem

iTrader: (48)

i always say to remove the kit, check everything thoroughly and re install it.


thats the best method...


JT

str8dum1

iTrader: (11)

check and check.
Thanks!

sentry65

iTrader: (11)

i don't understand what you mean by the blower working harder if there's a leak or even causing knock - that doesn't make sense at all

str8dum1

iTrader: (11)

That is what I was told, that the air was heating up and causing knock bc the blower had to work harder. I do recall him saying the car was knocking. We even tried filling the tank with new gas. However getting details on the rpm range it was knocking or how many times was never communicated.

The boost leak was finally settled on as the cause with no further reference to any knocking. So i dont even know if that was an issue in the final tune.

The more I chatted with the turbo guys around here, made me also question this explanation. They wanted me to ask if its normal to see a torque drop during a leak. I can fix that fairly easy with a pressure check and redoing the piping/install Thats why I was wondering about ignition problems, exhaust problems.

My map doesnt look like its pulling timing or fuel at the top (ie the values continue in the same direction as the previous row/column)

I know there's some sort of leak as the power stops rising well before redline. So 1st off that needs to be fixed. I'd just hate to get on the dyno and still have the top end break up. Wastes the tuner's and my time.

Thanks everyone.

jpc350z

What does the red one have that makes the unbelievable Tq?

Biochem7

iTrader: (8)

I had a boost leak that was undetected during the dyno. The MAF housing that connects to one of the intercooler pipes via screws could be your leak. If you tighten the screws too much you could have warped the plastic. Try some hondabond and see if that helps.

str8dum1

iTrader: (11)

as part of the fix, i am using a silicon hose between the MAF and the metal tube. cut the square pieces off completely.

how did you know you had a boost leak if it wasnt detected on the dyno??

Biochem7

iTrader: (8)

On the dyno, my curves were perfectly smooth and the boost curve was smooth all the way to redline. But, I only made 6 psi with the 3.12 pulley which was not right. I just happened to put my hand by the MAF tube and felt some air so I tighten the bolts slightly and ran my car later on and made ~7 psi. After the hondabond, I was making close to 8 psi of boost at redline.

Biochem7

iTrader: (8)

One more thing, did you run 1 step colder plugs before the power drop? My buddy just rebuilt his motor and lost some torque even though he is running essentially the same boost. He thinks its because he is running 1 step colder plugs now.

str8dum1

iTrader: (11)

Interesting, as your experience is complete opposite of what I am seeing/ was told.

I put 1 step colder in before it was dyno'd/ tuned.

Thanks

FORZWIN

iTrader: (4)

Ditto, that's a good looking graph from a vortech. Interested in his setup..if available...

booger

iTrader: (6)

Do youi have a copy of your R-4 maps you can email me ? I can look at them to see how much timing is being pulled .

Audible Mayhem

iTrader: (48)

basically that red set up has a Performance Factory installed system, we did the 2.87 pulley on a non revup. the car has headers, test pipes and a JIC Ti single exhaust. it actually made more power but i had to back the timing down on it due to it starting to knock.

we make sure we take the extra steps to make sure everything is really tight and leak proof. we have seen many many things cause boost leaks and know what to avoid to save the customer time and money.

that car is very very fast...