Notices

EFI Conversion, Tuning and Over Boost

 
Old 10-26-2007, 11:10 PM
  #1  
Mondragon
User
Thread Starter
 
Mondragon's Avatar
 
Join Date: Jun 2002
Location: Australia
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Default EFI Conversion, Tuning and Over Boost

Hi guys,
I Have rebuilt my engine after it seized no.5 conecting rood to the crank. i have added a bunch of stuff that i have picked up from this forum but am having problems tuning. if some one could lend me some advice i would appreciate it.

Rebuild
New crank shaft
One new conrod
New fly wheel and clutch
Rings, bearings, gaskets plus all the bits that usualy wear out

Mods
3.2 carrera manifold
Ported heads, new valve guides
964 NA cams
blue Printed Crank and Rods
2 x Additional front mounted oil coolers
6 x 800cc injectors
Autronic 500R ignition
3 x Dual MSD coils
Garett GT35R BBTurbo 0.7 AR
Schnell Extractors
Tial 46mm WG 0.5 bar spring
Full Bay Custom Inter Cooler
Autronic SM4 Computer

Well we had the car on the Dyno at Nerang on the Gold Coast (Australia) the tuning went ok. The engine runs smoothly how ever the engine tuner tells me that at about 5500rpm the boost begins to creep substantialy and becomes uncontrolable. so he has set a temporary RPM cut out at 5800RPM untill we can sort somthing out to dump all of that extra boost.

The car makes 300.7kW at the rear Wheels @ 5800 RPM and 620Nm of torque at 5200 RPM. The RWHP figure is well short of what to guys are achieving in the US. This concerns me, however the torque figure seems higher??

My tuner says that the US figures are always inflated for some reason. i dont know about that and dont want to start an argument there..

can any of you give me some ideas to solve my over boost problem. the exhaust pipe runs straight out of the turbo No mufler. very noisy but sounds great.

also what do you think about the out put figures on the Dyno.

see attached Graph and pictures.

general driving impressions: the performance is incredible it accelerates so quickly that you have to be careful wher you do it because you run out or road in a hurry. all the gears feel strong even 4th at 100km/s has good acceleration.
the engine is crap to drive when it is cold. the idle is eratic until the enging gets a bit of temp into it. that doesnt bother me so much as it warms up quickly. also drive ability at low RPM is a bit cranky but thats to be expected considering the other Mods..

look forward to some advice.
Alex...
Attached Images    
Mondragon is offline  
Old 10-27-2007, 08:18 AM
  #2  
nathanUK '81 930 G50
Super User
 
nathanUK '81 930 G50's Avatar
 
Join Date: Sep 2005
Location: England UK
Posts: 3,508
Likes: 0
Received 0 Likes on 0 Posts
Default

Got any more pics of your wastegate on the car? Need to see the exhaust outlet tube of it.
nathanUK '81 930 G50 is offline  
Old 10-27-2007, 09:26 AM
  #3  
125shifter
User
 
125shifter's Avatar
 
Join Date: Jan 2005
Location: Houston, TX
Posts: 1,054
Likes: 0
Received 2 Likes on 1 Post
Default

You have a 0.5 bar spring, so do you have a waste gate controller? If so, are the parameters set correctly in the ECU?

Your driveability at low rpm should be good when it's warm. Sounds like a bit more tuning is needed.
125shifter is offline  
Old 10-27-2007, 09:30 AM
  #4  
pzull
User
 
pzull's Avatar
 
Join Date: Nov 2002
Location: 2 ends of the Pacific
Posts: 761
Likes: 0
Received 0 Likes on 0 Posts
Default

With your setup using 964 cams, driving with cold engine shouldnt be a problem at all. Mine's smooth as silk with cold engine and idles well too. Only runs richer at at slightly higher rpm when cold
pzull is offline  
Old 10-27-2007, 03:37 PM
  #5  
Geoffrey
Super User
 
Geoffrey's Avatar
 
Join Date: Dec 2001
Location: Kingston, NY
Posts: 8,305
Likes: 0
Received 1 Like on 1 Post
Default

Can you post a picture of the wastegate circuit? It may be to restrictive ie too small or taken from only one back. What size is your wastegate and what brand?
Geoffrey is offline  
Old 10-27-2007, 07:21 PM
  #6  
Mondragon
User
Thread Starter
 
Mondragon's Avatar
 
Join Date: Jun 2002
Location: Australia
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Default Waste Gate Details

Guys, the Waste gate is a new Tial 46mm unit. The hose connections are 6.5mm. I am using hose to match the hose barbs on the waste gate. The Screamer pipe on the waste gate is 42mm id. The waste gate is controlled by and autronic small boost valve controller. There are no kinks in the hoses. Both hoses run from the waste gate to the controller. One of them then T's off and runs to pipe exiting the inter cooler before the throttle body. See attached pictures.

thanks for your help guys Alex..
Attached Images    
Mondragon is offline  
Old 10-27-2007, 07:44 PM
  #7  
A.Wayne
Formula One Spin Doctor
Rennlist Member
 
A.Wayne's Avatar
 
Join Date: Jan 2005
Location: RPM Central
Posts: 20,448
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello ,
If you can find out what correction factor your dyno operator was using, it will make the comparisons a lot easier..If your wastegate setup proves to be good, the turbo combination could be your problem . A .7 AR will spool very quickly and feel super, but that's a pretty small back housing for such a big engine ..., it could positively account for the boost creep , as the turbine speed will still stay high enough to produce boost creep on the top end . We use closer to a 1.0 on engines reving to 7 K and bigger on 3L plus engines reving to 8 K plus.....when using a GT35R i would look into your turbo Combination ......
A.Wayne is offline  
Old 10-27-2007, 07:48 PM
  #8  
A.Wayne
Formula One Spin Doctor
Rennlist Member
 
A.Wayne's Avatar
 
Join Date: Jan 2005
Location: RPM Central
Posts: 20,448
Likes: 0
Received 0 Likes on 0 Posts
Default

Connect the wastegate direct and look again for boost creep , If it still continues and you can hear the wastegate opening , then it is your small backhousing ..
A.Wayne is offline  
Old 10-27-2007, 07:51 PM
  #9  
125shifter
User
 
125shifter's Avatar
 
Join Date: Jan 2005
Location: Houston, TX
Posts: 1,054
Likes: 0
Received 2 Likes on 1 Post
Default

The 46mm Tial and stock are large waste gates and need a good size controlling valve. Is your's big enough?

The other thing to check is the waste gate valve parameters in the ECU.
125shifter is offline  
Old 10-27-2007, 08:05 PM
  #10  
Mondragon
User
Thread Starter
 
Mondragon's Avatar
 
Join Date: Jun 2002
Location: Australia
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Default

I have just had a look on the Autronic web site and have found that they have a larger boost controler valve with 1/4" barb connectors. The connectors on mine are 1/8 NPT, the hose im using is 1/4". this could be an issue. i hope i dont have to change the exhaust housing. the Turbo was recommended to me By Ray Hall in Cairns. He is a Pro..anyway i hope so..
Alex..
Mondragon is offline  
Old 10-27-2007, 08:23 PM
  #11  
jimculp
Shop Rat
Rennlist Member
 
jimculp's Avatar
 
Join Date: Jan 2006
Location: SE of Georgia
Posts: 2,451
Likes: 0
Received 0 Likes on 0 Posts
Default

Mondragon,

I have a very similar build but with a K27 HFS. I am still breaking in my engine, but I notice when I pass 5K rpm (even with no boost showing) I hit a wall and the engine seems to abruptly stop making torque. What are the symptoms you experience at 5K rpm?

Thanks,

Jim
jimculp is offline  
Old 10-27-2007, 08:58 PM
  #12  
DonE
User
 
DonE's Avatar
 
Join Date: May 2005
Location: Brooks, GA
Posts: 792
Likes: 0
Received 0 Likes on 0 Posts
Default

I would bet your solenoid is just fine regarding the size of the connectors. All the solenoid is doing is regulating outside air to the top of the wastegate. Your build and mine are similar and I have not problems with the controller.

So, are you saying that you can maintain the desired boost until you get to 5800? For example, driving at 4000 rpm, go full throttle and the desired boost is nailed, then climbs again at 5800? If so, that's an exhaust wastegate circuit, not a solenoid or the wastegate itself.

Also, with your build, I would expect great drivability cold, hot and everything in between - including idle.
DonE is offline  
Old 10-27-2007, 10:12 PM
  #13  
Mondragon
User
Thread Starter
 
Mondragon's Avatar
 
Join Date: Jun 2002
Location: Australia
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Default

Jim,
The engine feels fine at 5K. Iwill have to put a boost guage on it to see what it's doing. As far as cold drive ability goes i agree it should behave like factory car however when the heads were off the engine i didnt realise that that modle engine didnt have a cylinder head temp sensor. My mechanic didnt advise me to have one machined in so we are sensing engine temp from a cyl head temp sensor fitted to where the cold start time switch is mounted in the timing chain housing..
Alex..
Mondragon is offline  
Old 10-29-2007, 10:16 AM
  #14  
125shifter
User
 
125shifter's Avatar
 
Join Date: Jan 2005
Location: Houston, TX
Posts: 1,054
Likes: 0
Received 2 Likes on 1 Post
Default

I don't have a head temp sensor. I put an oil temp sensor in the breather cover on top of the engine. Seems to work fine for engine temp.
125shifter is offline  

Thread Tools
Search this Thread

Contact Us - About Us - 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.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: