Startup soon...AGAIN - SRT Forums

vschaos · 07-23-2007, 01:02 PM

Well finally after the car sitting for MONTHS I should have the car running again soon. I had originally had the MS hooked up to my car when I had a 50 trim on the vehicle. At the time I still had hard cold and warm starts...7 seconds or so for startups. What started my downtime was my driver side power steering line broke and sprayed fluid all under the car. I was having hard steering issues and saw smoke...lucky car didnt catch fire. So while I was trying to find another line I purchased a EGT guage. I got that in and took the turbo manafold off to install a EGT guage and figure what the heck lets get a bigger turbo

So I sold that turbo and bought a new one. In the process of getting the new one built I sold my 3 inch exhuast as well. I got the new turbo in, but had no exhaust still and have to get a custom o2 housing made. I figured with the car still down why not upgrade the fuel system as well. So I bought a return line setup from a friend and installed...I then sent my fuel assembly off to ptperformance to have him mod it to fix the bottlekneck fix.

So as of right now I am waiting on a few items. For the turbo I didnt get the adapter that bolts to the turbo for the oil feed line too hook too. I also need the hose that is the oil return that goes from the turbo to the back of the block since I had to cut the one I had off the 50 trim. the o2 housing should be shipping today as well as the exhaust(crossing fingers). I am hoping he got done with the fuel assembly as well and it will also ship today.

New parts since last tune...

GT35R turbo housing with GT 40 wheel and .63 A/R housing
Return Line
Bottlekneck fix
4" SEE
EGT guage

I am hoping that I wont have to retune a whole bunch, but its obvious that my fuel will be screwed. I plan on driving it normal under no boost conditions at first to get driveability down without the 1:1 vaccume line hooked up. I figure if I put it at 58psi static fuel pressure it should be just like the 50 trim under no boost conditions. Then again I now have the bottlekneck fix soooo thats a whole lot more fuel now

Whats a good recommendation as to how much fuel pressure to run...40-45? Then of coarse hook up the 1:1 vaccume line when boosting. Gosh its never ending....I guess I am just mod happy

boost junkie · 07-24-2007, 06:02 AM

You can try running a check valve on the line to the regulator so it only sees boost. Then you can set the fuel pressure at idle to 58psi and it will only go up from there.

SpeedEuphoria · 07-24-2007, 07:13 AM

fuel pumps dont like high pressure and the flow hits a wall. It depends on what size injectors you have and how much boost you want to run. I have an external walboro 255 and will be running 30psi, so I set my base at 40psi(vac un hooked) I dont have a checkvalve so it drops below 30# in vac. This way the when at 30psi the fuel press is ~70psi and my pump pushes enough fuel for ~550hp(this also varies w/ voltage). I have 75# injectors also but didnt know at the time I bought them that this was rated @58psi so these will fall short in my setup when I raise the boost that high. http://shopping.lightningmotorsports...55lph-p-8.html

vschaos · 07-24-2007, 02:11 PM

Quote: Originally Posted by SpeedEuphoria

fuel pumps dont like high pressure and the flow hits a wall. It depends on what size injectors you have and how much boost you want to run. I have an external walboro 255 and will be running 30psi, so I set my base at 40psi(vac un hooked) I dont have a checkvalve so it drops below 30# in vac. This way the when at 30psi the fuel press is ~70psi and my pump pushes enough fuel for ~550hp(this also varies w/ voltage). I have 75# injectors also but didnt know at the time I bought them that this was rated @58psi so these will fall short in my setup when I raise the boost that high. http://shopping.lightningmotorsports...55lph-p-8.html

I have 750cc injectors that are rated at 43psi. I also have the walbrao 255 fuel pump with the bottlekneck fix so has plenty of fuel. Everyone I have talked to thus far has said to put the base static pressure at 40-43psi then hook up the vaccume line for the 1:1 to work. I only plan to have about 430-450whp right now until I can build the motor up.

**guhfluh** · 08-01-2007, 12:41 PM

You have the wideband still right? Make sure the exhaust is long enough with no leaks, Turn off all ego correstions, start the car and let it idle. turn the pressure down until the afr is back to where it was. That should get you in the ballpark. Put the boost down as low as possible and start logging and tuning. Spark will have to be retuned also, but shouldn't be too far off.

vschaos · 08-01-2007, 05:12 PM

Quote: Originally Posted by guhfluh

You have the wideband still right? Make sure the exhaust is long enough with no leaks, Turn off all ego correstions, start the car and let it idle. turn the pressure down until the afr is back to where it was. That should get you in the ballpark. Put the boost down as low as possible and start logging and tuning. Spark will have to be retuned also, but shouldn't be too far off.

Yea I had the full 3 inch turbo back and then a 3 inch dump....with both it took that long too start. I am STILL waiting on damn parts....starting on month 3 here soon. Yes I have wideband as well. Soon as I get everything in I will post up here.