Single Turbo SC400 and Running
01-17-08, 06:23 PM
#46
You're all right. I used the term "max out" to make it simple. From what I understand, the MAF reads the air flow by the temperature. More air = cooler. That's when the current drops and changes the voltage. This sends the signal to the ECU.
Anyway, we're in O.C. Land of the sun.
Anyway, we're in O.C. Land of the sun.
01-19-08, 08:37 AM
#47
Rookie
Join Date: Jun 2003
Location: Virginia
Posts: 94
Likes: 0
Received 0 Likes
on
0 Posts
SC MAFs are karman vortex, not hot wire. Vortices are created by the honeycomb and then counted inside the sensor to determine airflow. I'm sure there is a limit to what it can accurately read, but that limit is based on more things than boost pressure alone..
01-19-08, 10:12 AM
#49
Lexus Champion
iTrader: (2)
Join Date: May 2004
Location: Tennesee
Posts: 3,465
Likes: 0
Received 0 Likes
on
0 Posts
I was able to run 17psi without any issues on teh Stock MAF, the engine wasnt stock though. If I were to do it again, and I certainly hope to, I think I would go MAP though
Ryan,
Thanks for reminding me. I'm not exactly sure if the stock MAF can max out at 15 psi. You may be right. It's just that I see David, Morris, Chrisman or maybe Rdmfan all passed 15 psi without mentioning any modified MAF.
For fuel, I appreciate that you reminding me. Yes, I know that fuel supply is the major and critical thing for the turbo system. I already have the FMU for low boost with stock injectors. I have a set of Supra injectors and I'll toss them in and run 9 psi after I dyno the car with stock injectors. The final goal will be 12 psi to be on the safe side with 2 1000 cc/min injectors and the Split Second (I think Morris and Justen ran 15 - 17 psi with stock engine, and David ran 20 psi with stock engine and thicker head gaskets.)
1 thing I like about the SC is it idles very lean, but once I step on the gas, the AEM wideband reads 12:1 easily.
Thanks for reminding me. I'm not exactly sure if the stock MAF can max out at 15 psi. You may be right. It's just that I see David, Morris, Chrisman or maybe Rdmfan all passed 15 psi without mentioning any modified MAF.
For fuel, I appreciate that you reminding me. Yes, I know that fuel supply is the major and critical thing for the turbo system. I already have the FMU for low boost with stock injectors. I have a set of Supra injectors and I'll toss them in and run 9 psi after I dyno the car with stock injectors. The final goal will be 12 psi to be on the safe side with 2 1000 cc/min injectors and the Split Second (I think Morris and Justen ran 15 - 17 psi with stock engine, and David ran 20 psi with stock engine and thicker head gaskets.)
1 thing I like about the SC is it idles very lean, but once I step on the gas, the AEM wideband reads 12:1 easily.
01-21-08, 02:18 AM
#52
I like to have a little update. I really boost my car today. It's at a constant 6 psi. I thought I can initially boost it at 7-8 psi but I guess the pressure loss is due to the plumbing. It's not much but it drives like a beast. I'm really happy because there's no turbo lag whatsoever, and no other problems. The boost kicks in right away like a big N/A engine. The A/F gauge reads around 12 psi at WOT, 14.7 - 15 at cruising, and 17-18 at idle..Oh..Oh. I think it's normal. 
I need to get the body fixed up and I'll dyno it very soon. I hope I can get ready for 12 psi in 2 months.
I need to get the body fixed up and I'll dyno it very soon. I hope I can get ready for 12 psi in 2 months.
01-21-08, 11:05 AM
#53
Lexus Champion
Join Date: Jan 2003
Location: SGV
Posts: 1,621
Likes: 0
Received 0 Likes
on
0 Posts
Steve is too excited and put 12 psi at WOT. He meant the AFR is at 12 at WOT. I test drove his car last night around 11 pm along with JamesN. This is no joke. The car is very responsive and pulls like a rocket. The car felt very smooth from idle to redline. No pinging or anything. Love driving that car and he did a great job. Steve, any chance producing your kit for cheap so the public can do what you did instead paying $2,500 for a set of headers?
01-21-08, 11:39 AM
#54
Steve is too excited and put 12 psi at WOT. He meant the AFR is at 12 at WOT. I test drove his car last night around 11 pm along with JamesN. This is no joke. The car is very responsive and pulls like a rocket. The car felt very smooth from idle to redline. No pinging or anything. Love driving that car and he did a great job. Steve, any chance producing your kit for cheap so the public can do what you did instead paying $2,500 for a set of headers?
02-03-08, 08:06 AM
#56
Lexus Champion
Join Date: Jan 2003
Location: SGV
Posts: 1,621
Likes: 0
Received 0 Likes
on
0 Posts
Steve came by last night with his exhaust fixed and alignment. The car idles perfectly like stock and I took it to the freeway. From the red light dead stop, the tires peels at around 3k rpm for about few seconds and it shoots straight forward to redline. As I enter the freeway, the car shot to 90 mph as I merge to the left lane. The car is very smooth and no lag. With 6 psi running on his stock 1uzfe motor I would assume he is making about 275-290 rwhp.
I had a chance to test drove a 1jzgte SC300 with auto. I must say it am not impress with it. I took off like my 2.4L Previa van. Boost comes on and the car pulls at around 3k to 5k and everything flat out. The 1j has stock turbos with 10 psi. Not too impress with it.
Honestly and not being bias to any engine. I would prefer 6 psi on hte 1uzfe than the 10 psi 1jzgte. The torque was feel from idle to redline and 1jzgte is sluggish and die out at 5k. I know Steve is very happy and very proud of all his hard work and finally pays off. I really encourage Steve to bump the boost up to 12 psi with additional fuel. Dyno is next for him.
I had a chance to test drove a 1jzgte SC300 with auto. I must say it am not impress with it. I took off like my 2.4L Previa van. Boost comes on and the car pulls at around 3k to 5k and everything flat out. The 1j has stock turbos with 10 psi. Not too impress with it.
Honestly and not being bias to any engine. I would prefer 6 psi on hte 1uzfe than the 10 psi 1jzgte. The torque was feel from idle to redline and 1jzgte is sluggish and die out at 5k. I know Steve is very happy and very proud of all his hard work and finally pays off. I really encourage Steve to bump the boost up to 12 psi with additional fuel. Dyno is next for him.
02-03-08, 12:54 PM
#59
Rookie
Join Date: Oct 2005
Location: CA
Posts: 78
Likes: 0
Received 0 Likes
on
0 Posts
This MPG doesn't really suffer under normal driving condition, but it does suffer under boost. After everytime I boosted, the gas needles drops down about 1 mm. I boosted for about 15 times for a distance of 25 miles, the gas dropped down 1/4 way down.