i want to run and hold 10psi, the problem is that if i set my controller so i have 10 it falls off to about 6 as i near redline, i thought mabey the turbo was just being overflowed, (like the stocker) but if i unhook the wastegate hose, and feather the throttle to control the boost i can get easily 15psi at 8000rpm

the turbo is a s5 hybrid, t5/6 compressor, and mega wastegate porting with almost too much backcutting. the trubo was assembled/rebuilt by me

i thought that mabey my problem was that i only had a bleed type controller, so i bought a ball spring/bleed type......still does the same thing

what is causing this??????? someone please help me
zac

 

15psi is to much boost for stock IC to handle. Your timing must be retarded for this kind of boost. As well its not good to be fethering the car at 8k like that. These 2 combinations will detinate your motor! plz be carefull.

If you are droping boost it is leaking. Does it drop when you hold the RPM? Or will it drop under heavy accel/load? Look at VAC leaks waste gate leaks IC leaks. Alot of times if you push a turbo to its max it will leak down just b/c its not capable of sustaning such high boost.

 

^^^ LIES LIES LIES

just run a boost controller that learns your boost charistics... like EVC, AVC-R, etc.

also... 3 PSI is too much boost for the stock IC to handle....

 

WOW......... That was usefull.

 

an ebc won't help that problem that much. it will still drop down.

 

You just answered your own question.
MBC (mechanical boost controllers) only raise your boost levels relative to how the stock boost levels were.

You want SOLID boost, stop wasting your money on the cheap stuff and get a closed-loop EBC.


-Ted

 

You know what...

Stop spreading misinformation like this is you have no idea what you are talking about.

The A'PEXi AVC-R will give you whatever preset boost level you choose, as long as you're allowing it to work under it's normal parameters (i.e. no major boost spiking, stable boost levels, etc.).
The older HKS EVC III ATM was able to do this too.
I heard the Blitz SBC can do this too - can anyone confirm?

The GReddy PRofec CANNOT - it is not a closed-loop EBC.


-Ted

 

[QUOTE=RETed]You just answered your own question.
MBC (mechanical boost controllers) only raise your boost levels relative to how the stock boost levels were.

that makes alot of sense^^....ill just spend the money for an ebc
thanks

 

Wow, you actually removed the vacuum line that went to the wastegate acctuator....you have some big big *****

What kinda of manual boost controller are you using?

 

Woah, sorry tough guy.

 

THANK YOU Ted.

 

lol, it was pissing me off so i had to find out, i have a wideband and afc, so i turned the fuel way up and i know my afr's werent a problem

i first had the standard turboxs controller, then i bought this one http://cgi.ebay.com/ebaymotors/ws/eB...978154785&rd=1
that one worked better than the turboxs controller

so an ebc will make that much difference huh?
zac

 

the problem you are having is
the wastegate is opened too much for the high boost
you want a boost controller like the ones Ted and I mentioned
that way it can control your wastegate correctly, thus, you have a solid boost plane (not curve.


dont listen to iceblue... his intelligence is as high as his spelling... which, if i may add... is not high at all...

 

jesus you are ignorant. That is exsctly what is happening. Oh well maybe that sliped your thoughts again.

I recal telling him what to check that can cause that. And you and ReTed told him a controller to manage the waste gate leak in this case. Wow maybe you can see now that it is spelld out for you.

 

How long are the vacuum lines....running from your turbo to the MBC?

 

Hmmm..

This thread is AWESOME!

I personally ran over 15 PSI on a stock intercooler and stock turbo, which gave me a 13.4 1/4 mile on a stock motor with an SAFC. Was it smart? Probably not, but it can be done, and my motor survived quite nicely. Also, my timing was stock.

 

the lines are 1/4"id, 8"length to the bc, and 15" from the bc to the wg.

i have been messing around by adding different springs to the wastegate to increase the preload and that has helped some

 

no greddy profec?

 

Why are you assuming something is wrong with his car in the first place?
Isn't it common sense to make sure everything is working correctly before modifying stuff???
I mean you wouldn't go stuffing a boost controller on an engine with a hurt apex seal, right???



-Ted

 

No, contrary to popular believe, the PRofec is not a closed-loop EBC.


-Ted

 

Didn’t. I asked him several questions that he has never replied to. And then gave some suggestions on what parts can cause boost to leak. Expecting a reply of what he has tried or figured out from a previous or soon to come inspection.

But perhaps he was saying he didn’t know what would cause it and was asking for suggestions.

I said his waste gate is leaking, his IC pipe is leaking, or his turbo is being over boosted and unable to hold that amount of boost.

slpin posted to get a electric boost controller like AVC-R

You then posted that his waste gate was insufficient and incapable of holding the boost as he wants and needs a closed EBC controller such as AVC-R to maintain it.

 

"I said his waste gate is leaking, his IC pipe is leaking, or his turbo is being over boosted and unable to hold that amount of boost."

he said it boosted 15psi with the wastegate capped off.
a leaking wastegate would make his boost go higher
a leaking IC pipe would not allow him to boost and hold the previous 15psi that he had achieved.
you are wrong.
you need to shut up and give up... go get your dad to work on your car or something...
i dont like you, and pretty soon, i dont think that the lovely beautiful sexy ted will like you either!

 

He never said he could sustain boost. What I got out of it is he could reach 15 but had to work to keep it.

Allright on my friends GST runing 20PSI on stock T and a MBC. He could peak 20psi but it would creep to 17. B/C of insufichant turbo. Put a T3/T4 hybrid on it and ran 18psi stable. Same car when it was boosting 15psi used to hit 15 and leak down to 10. His IC pipe had a leak. Fixed and held 15psi.

a leaking wastegate would make his boost go higher.......
Yea that is right b/c it will allow more exhaust flow. Then how does a EBC work? It close the flapper on the waste gate?

 

hmm...i had always thought Ted was a guy and that picture was of his girlfriend/wife or something. I dunno.

So is stock boost supposed to drop off at higher RPMs? Since you said a MBC just reflects the normal boost curve. Is it adding a percentage or increasing by just a flat amount?

 

Why are you comparing an FC turbo to a DSM turbo?


Most EBC's are run as a "bleeder".
You T off the wastegate line, and it bleeds a certain amount of pressure, depending on how you set it.
Fancy ones are able to input RPM, and you get to program the boost "curve" dependent on RPM.
Even fancier version (i.e. A'PEXi AVC-R) have "self learn" that allows the EBC to run the most aggressive boost ramp your engine can handle.
Control is through a PWM solenoid...


-Ted