Go Back  Miata Turbo Forum - Boost cars, acquire cats. > Performance & Tuning > Prefabbed Turbo Kits
Reload this Page >

couple weird problems ive been having... help!

Prefabbed Turbo Kits A place to discuss prefabricated turbo kits on the market
Sponsored by:
Sponsored by:

couple weird problems ive been having... help!

 
Old 02-04-2007, 08:02 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Aug 2006
Location: Cedar City, UT
Posts: 238
Total Cats: 4
Default couple weird problems ive been having... help!

i have a stock greddy kit on my 93 with a bipes and rx7 afm. running at 5 psi

got two questions

1) i will hit 5 psi at 3.5 rpm but i dont get that surge of power till i hit 4k

my gauge is reading boost at one of the fittings that used to go to the charcoal canister. if im in 4th gear ill floor it and get 5psi at 3.5 but there is no increase in pull, then once it gos past 4k it will begin to accelerate much more rapidly is this just the camshaft timing or do i not have my bipes setup correctly

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi

again it this just something with my timing or what?
Dlaitini is offline  
Old 02-04-2007, 08:09 PM
  #2  
Junior Member
 
Join Date: Jun 2006
Location: Austin, Texas
Posts: 257
Total Cats: 0
Default

Fuel pressure gauge?
TurboMiatKid is offline  
Old 02-04-2007, 09:04 PM
  #3  
Senior Member
 
Join Date: Mar 2006
Location: Ireland
Posts: 534
Total Cats: 0
Default

Your getting your boost reading from where ?
You should be getting the reading from the top of the injector manifold, the little metal nipple thingy.
Why are you running down at 5psi ?
Tighten up that wastegate a few turns and get up to or over 6PSI !!
Fergus is offline  
Old 02-04-2007, 09:18 PM
  #4  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 76,620
Total Cats: 2,317
Default

Originally Posted by Dlaitini View Post
i have a stock greddy kit on my 93 with a bipes and rx7 afm. running at 5 psi

got two questions

1) i will hit 5 psi at 3.5 rpm but i dont get that surge of power till i hit 4k

my gauge is reading boost at one of the fittings that used to go to the charcoal canister. if im in 4th gear ill floor it and get 5psi at 3.5 but there is no increase in pull, then once it gos past 4k it will begin to accelerate much more rapidly is this just the camshaft timing or do i not have my bipes setup correctly

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi

again it this just something with my timing or what?

1. Lean tip-in (research o2 clamp)
2. In your head....you're seeing a fast increase in Tq and then it plateus quickly at only around 130rwtq or so.
Braineack is offline  
Old 02-04-2007, 10:57 PM
  #5  
Senior Member
iTrader: (1)
 
Join Date: Sep 2006
Location: Hong Kong
Posts: 523
Total Cats: 0
Default

Brainack is right.. should be a lean tip in...needing O2 clamp.

Could also be the Vortech not clamping down fuel pressure till 1.5psi as said on POP's test. http://home.bellsouth.net/p/s/commun...pid=224302&ck=
Mimime is offline  
Old 02-05-2007, 01:23 AM
  #6  
Junior Member
 
Join Date: Oct 2006
Posts: 257
Total Cats: 0
Default

im going out on a limb here, but i think maybe your wastegate actuator hose popped off....i think i had similar problems once and i figured out that it was that......
shinobix is offline  
Old 02-05-2007, 02:56 PM
  #7  
Senior Member
iTrader: (1)
 
Join Date: Mar 2006
Location: Tucson "it's 110" Arizona
Posts: 1,017
Total Cats: 0
Default

Just to be obnoxious: o2 clamp

People say the Greddy is like an on/off switch
UofACATS is offline  
Old 02-05-2007, 03:12 PM
  #8  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,651
Total Cats: 111
Default

I don't think it's a lean tip in. That's just how the greddy kit is.

Check out this screen capture of a Feb 04, 2007 datalog:

The yellow line is engine speed (RPM). The blue line is MAP. The Y axis is marked for RPM, not pressure, sorry. The engine reached atmsopheric pressure at 1900 rpm, and 1 psi positive pressure by 2100 rpm. You can see how long the turbo takes to spool, as it doesn't reach 10 psi until 5k rpm.

Don't underestimate the need to downshift. It's usually better to be in a gear too low than in a gear too high.
__________________
DIYAutoTune.com Tech Support
10AE-T|BEGi S4|MSPNP-Pro EMS|Enthuza Duals|6UL|Etc
Track Rat|2001|VVT|MS3-Pro EMS|Enthuza|Exocet in Progress

Originally Posted by concealer404 View Post
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 02-05-2007, 03:27 PM
  #9  
Senior Member
iTrader: (1)
 
Join Date: Mar 2006
Location: Tucson "it's 110" Arizona
Posts: 1,017
Total Cats: 0
Default

Originally Posted by Dlaitini View Post
got two questions

2) the 5.5-7k it almost seems like im running out of air even thought it stays at a constant 5psi
Do you have stock exhaust?
UofACATS is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
patsmx5
WTB
1
10-01-2015 09:43 AM
mx592
Suspension, Brakes, Drivetrain
1
10-01-2015 12:45 AM
nick470
MEGAsquirt
1
09-30-2015 10:32 PM
shooterschmidty
Engine Performance
8
09-30-2015 10:28 PM


Thread Tools
Search this Thread
Quick Reply: couple weird problems ive been having... help!


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.