Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   boost overshoot going uphill (https://www.miataturbo.net/diy-turbo-discussion-14/boost-overshoot-going-uphill-32873/)

Atlanta93LE 03-18-2009 07:45 AM

boost overshoot going uphill
 
I'm getting boost overshoot when under high load, i.e. going up a hill. Is there any way to calm that down? I'm thinking removing the bottleneck in my exhaust might help...thoughts?

Atlanta93LE 03-18-2009 11:54 AM

I can't imagine I'm the only person experiencing this. Bueller?

m2cupcar 03-18-2009 12:14 PM

this is with Ebc?

Atlanta93LE 03-18-2009 12:37 PM

Yup, EBC.

Basically, I hit rock solid 9-10 psi on a flat road, and a fairly solid 12 psi going uphill, or any other time there is excessive load on the engine.

sixshooter 03-18-2009 01:29 PM

There have been two other threads on this recently. Both determined that the 16G either doesn't like little exhausts and/or low boost pressure.

Your wastegate is probably experiencing too much backpressure from the exhaust to work efficiently.

If the larger exhaust doesn't fully eliminate your issue the wastegate opening is possibly too small to bleed off the exhaust efficiently. It can be ported and a larger flapper installed. Not likely that this will be a problem after you open up your exhaust system.

Someone else said that they had no problem with creep, but they had a lot higher boost setting and probably had other factors in their favor.

m2cupcar 03-18-2009 01:31 PM

crush bends ftl ;)
You need to update to the new MS ebc code for closed loop. :bigtu: Do you make less boost going downhill (less load)? It would seem to me that open loop bc is the problem.

sixshooter 03-18-2009 01:34 PM

Where are you getting your wg signal from?

levnubhin 03-18-2009 01:39 PM

No hills here in FL, sorry. :dunno:
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Braineack 03-18-2009 01:45 PM


Originally Posted by m2cupcar (Post 383559)
crush bends ftl ;)
You need to update to the new MS ebc code for closed loop. :bigtu: Do you make less boost going downhill (less load)? It would seem to me that open loop bc is the problem.


they come out with it yet?




ive hit a boost cut uphill once, i was in 4th and didnt feel like downshifting. the solution for me raising the boost cut :P

sixshooter 03-18-2009 01:47 PM


Originally Posted by levnubhin (Post 383568)
No hills here in FL, sorry. :dunno:

A hill is like a naturally occurring overpass with dirt filling underneath it. I saw one once as a kid.

Atlanta93LE 03-18-2009 01:55 PM


Originally Posted by sixshooter (Post 383555)
There have been two other threads on this recently. Both determined that the 16G either doesn't like little exhausts and/or low boost pressure.

Your wastegate is probably experiencing too much backpressure from the exhaust to work efficiently.

Someone else said that they had no problem with creep...

Hmm, not sure how I missed the other threads. I'll take a look around.
It's not creep per se, just hitting a higher boost and sticking there.


Originally Posted by m2cupcar (Post 383559)
crush bends ftl ;)
You need to update to the new MS ebc code for closed loop. :bigtu: Do you make less boost going downhill (less load)? It would seem to me that open loop bc is the problem.

Indeed, one crush bend (truthfully, it's a squeeze bend rather than a proper cruch bend :giggle:) ruins the party.


Originally Posted by Braineack (Post 383574)
they come out with it yet?

^ I second the question. I'd heard rumblings about MS2 stuff, but nothing for MS1.



Originally Posted by Braineack (Post 383574)
ive hit a boost cut uphill once, i was in 4th and didnt feel like downshifting. the solution for me raising the boost cut :P

This sounds like a plan, once I get a better tune up in that range.

Funny that this didn't happen with my old IC...

Atlanta93LE 03-18-2009 02:01 PM


Originally Posted by sixshooter (Post 383561)
Where are you getting your wg signal from?

right outside the compressor outlet

m2cupcar 03-18-2009 02:16 PM


Originally Posted by Atlanta93LE (Post 383582)
...Funny that this didn't happen with my old IC...

It was like having a crush bend on the other side of the turbo :D
You've disturbed the balance. Raise the boost limit and where will it end?
http://i158.photobucket.com/albums/t...ttacontrol.gif

sixshooter 03-18-2009 02:25 PM

In another recent thread it was discussed that the hot side of the intercooler should never be the source for your wastegate signal or boost gauge lines. Disregard the factory outlet nipple. Use a source between the IC and the throttle body. Much more reliable signal. The hotside will give you strange behaviors.

I'll hunt for the posts.

EDIT: Found one. Pay particular attention to Professor Joe Perez's dissertations as the thread progresses. https://www.miataturbo.net/forum/t32479/

levnubhin 03-18-2009 02:44 PM


Originally Posted by sixshooter (Post 383579)
A hill is like a naturally occurring overpass with dirt filling underneath it. I saw one once as a kid.


:eek5: You lie!
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

240_to_miata 03-18-2009 03:32 PM


Originally Posted by m2cupcar (Post 383559)
You need to update to the new MS ebc code for closed loop.

DO TELL where the new code is for MS1!!!

Atlanta93LE 03-18-2009 03:43 PM


Originally Posted by sixshooter (Post 383608)
In another recent thread it was discussed that the hot side of the intercooler should never be the source for your wastegate signal or boost gauge lines. Disregard the factory outlet nipple. Use a source between the IC and the throttle body. Much more reliable signal. The hotside will give you strange behaviors.

I'll hunt for the posts.

EDIT: Found one. Pay particular attention to Professor Joe Perez's dissertations as the thread progresses. https://www.miataturbo.net/forum/t32479/

Thanks for the link. I'll read through that one again, although I recall it mostly having to do with boost drop-off.

cardriverx 03-18-2009 03:53 PM


Originally Posted by m2cupcar (Post 383559)
You need to update to the new MS ebc code for closed loop. :bigtu:

WHAT!? They actually fixed it! I am getting so excited, where is this code!?!?!?

m2cupcar 03-18-2009 05:18 PM

Whoa - sorry guys - I was just BS'ing. :gtfo: I do have some working closed loop code. Though it's over ten years old... and in my LINK. ;)

cardriverx 03-19-2009 06:34 AM


Originally Posted by m2cupcar (Post 383714)
Whoa - sorry guys - I was just BS'ing. :gtfo: I do have some working closed loop code. Though it's over ten years old... and in my LINK. ;)

ohh your going to die. :hahano:


All times are GMT -4. The time now is 08:32 AM.


© 2024 MH Sub I, LLC dba Internet Brands