Single Turbo RX-7's Questions about all aspects of single turbo setups.

Too laggy, developing boost late

Thread Tools
 
Search this Thread
 
Old 04-21-11, 07:58 AM
  #1  
Junior Member
Thread Starter
 
fd3s-yo's Avatar
 
Join Date: May 2008
Location: Australia
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Too laggy, developing boost late

Hi all,

Just recently did a single turbo conversion with a Garrett T04z 1.32.

I found this set up to be laggy with full boost coming on around 5200 rpm. I didnt think much at the time that anything was wrong.

I then went to a 1.00 rear housing and expected boost to be somewhere between 4000-4500 rpm. To my surprise full boost came on later at 5500 rpm.

At first we thought there was no valve seat for the wastegate but when i jacked up the car today it was all there.

Any ideas on what the issue can be?
Old 04-21-11, 08:46 AM
  #2  
IRS 4 Life

iTrader: (12)
 
Bacon's Avatar
 
Join Date: Feb 2001
Location: Sicklerville, South Jersey!!
Posts: 2,634
Likes: 0
Received 2 Likes on 2 Posts
Is the motor ported?

Somethings not right, are you doing your boost runs on just the wg spring? whats your "full boost" PSI?

I see full boost (22psi) at about 4800rpm on a to4s (non bb like your Z) and with a 1.15 hotside
Old 04-21-11, 08:54 AM
  #3  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
Is your engine ported? What are you using for boost control? Have you verified no exhaust leaks? Have you pressure tested for boost leaks? What manifold are you using? Is it divided or undivided?
Old 04-21-11, 10:04 AM
  #4  
Junior Member
Thread Starter
 
fd3s-yo's Avatar
 
Join Date: May 2008
Location: Australia
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
the motor is street ported.

im using a greddy e01 to control the boost

how do i verify no exhaust leak or boost leaks?

its a custom manifold
Old 04-21-11, 10:43 AM
  #5  
Full Member

 
RotaryRX-007's Avatar
 
Join Date: Apr 2008
Location: Melbourne Beach, FL
Posts: 169
Likes: 0
Received 1 Like on 1 Post
Greddy electronics... FTL. Hate them. Disconnect that boost controller and run off the wastegate spring to see what happens.

Is it building boost through the pull or is it full boost or nothing? Controller might be opening the w/g early not allowing it to make boost.
Old 04-21-11, 11:17 AM
  #6  
Rotary Enthusiast

iTrader: (4)
 
DriftDreamzSS's Avatar
 
Join Date: Apr 2006
Location: Ventura
Posts: 1,236
Likes: 0
Received 3 Likes on 3 Posts
Originally Posted by fd3s-yo
how do i verify no exhaust leak or boost leaks?
Get a PVC cap from the hardware store that will fit in the coupler at your compressor inlet and drill and tap it for an air fitting or a valve stem. Connect an air compressor to it and pressure your whole intake to around your full boost psi, spray soapy water on all your couplers, vac lines, block off plates, tb and uim/lim flanges, every possible leak point, look for bubbles and listen for leaks.
Old 04-21-11, 07:00 PM
  #7  
Junior Member
Thread Starter
 
fd3s-yo's Avatar
 
Join Date: May 2008
Location: Australia
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RotaryRX-007
Greddy electronics... FTL. Hate them. Disconnect that boost controller and run off the wastegate spring to see what happens.

Is it building boost through the pull or is it full boost or nothing? Controller might be opening the w/g early not allowing it to make boost.
Its building boost but very slowly. i get about 5 psi at 5000 rpm with the 1.00 rear housing.
Old 04-21-11, 07:42 PM
  #8  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
5psi at 5000rpm is definitely sign that something's wrong. On my T04R (same as T04Z but not ball bearing) with large street port, divided 1.00 turbine housing and Feed stainless manifold I see 15psi at about 5000rpm.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
24seven_dada
3rd Generation Specific (1993-2002)
20
11-10-18 12:03 PM
Jeff20B
1st Generation Specific (1979-1985)
73
09-16-18 07:16 PM
Clacor
Single Turbo RX-7's
19
09-11-15 08:36 PM
High_Carb_Diet
Power FC Forum
1
09-05-15 09:07 AM



Quick Reply: Too laggy, developing boost late



All times are GMT -5. The time now is 09:47 PM.