Made dyno appt...Can't wait!
02-04-08, 12:05 PM
#31
Lexus Champion
Very good before AND after numbers 
Nice to see the dyno starting at a relatively low RPM. Not easy to do.
I am surprised that the runs seem to end before 6000rpm. Not sure if this is a dyno tachometer error or not. Also, the modified runs quit slightly before the "before" runs.
Keep in mind that dyno's definitely VARY on their readings. Another is air temperature, humidity and barometric pressure. The correction factors do not seem to accuratedly represent the big performance variance in these cars at different temperatures. OBDII can be a funny animal.
Another thing worth considering is how much the stock camshafts can produce especially with a fuel cut at 6300rpm. A very serious effort by RMS in Australia was made on the stock early engines using extremely good open headers and individual throttle bodies on optimal intakes. The early engines cam timing was similar to ours and had 1/2 point lower compression. Peak power at the engine (NOT RWHP) was 307hp @ 6500rpm and 271tq @ 5000. The reason I am talking about this is at some point the headers will NOT be the restriction. It will be interesting to see the results of the S&S on this car. Hopefully the ambient conditions will be as good. It is VERY easy for the SAME engine without mods to LOOSE 20rwhp with poor air. If the air is poor and looses 20rwhp and the headers give back say 15rwhp it would show a LOSS of 5rwhp when in fact the headers gave +15. This is only and example but should not be forgotten when doing comparisons.
I have seen cars dyno MORE and go SLOWER. Dynos are great tools but are no substitute for actual on the road measured performance.
As I write this I can't remember if you have done good solid 0-60 runs and 1/4 mile runs and recorded the air conditions for those runs. If not, do so. It will be very helpful for you in understanding your car.
Nice to see the dyno starting at a relatively low RPM. Not easy to do.
I am surprised that the runs seem to end before 6000rpm. Not sure if this is a dyno tachometer error or not. Also, the modified runs quit slightly before the "before" runs.
Keep in mind that dyno's definitely VARY on their readings. Another is air temperature, humidity and barometric pressure. The correction factors do not seem to accuratedly represent the big performance variance in these cars at different temperatures. OBDII can be a funny animal.
Another thing worth considering is how much the stock camshafts can produce especially with a fuel cut at 6300rpm. A very serious effort by RMS in Australia was made on the stock early engines using extremely good open headers and individual throttle bodies on optimal intakes. The early engines cam timing was similar to ours and had 1/2 point lower compression. Peak power at the engine (NOT RWHP) was 307hp @ 6500rpm and 271tq @ 5000. The reason I am talking about this is at some point the headers will NOT be the restriction. It will be interesting to see the results of the S&S on this car. Hopefully the ambient conditions will be as good. It is VERY easy for the SAME engine without mods to LOOSE 20rwhp with poor air. If the air is poor and looses 20rwhp and the headers give back say 15rwhp it would show a LOSS of 5rwhp when in fact the headers gave +15. This is only and example but should not be forgotten when doing comparisons.
I have seen cars dyno MORE and go SLOWER. Dynos are great tools but are no substitute for actual on the road measured performance.
As I write this I can't remember if you have done good solid 0-60 runs and 1/4 mile runs and recorded the air conditions for those runs. If not, do so. It will be very helpful for you in understanding your car.
02-08-08, 06:12 AM
#32
From another thread...
The latest,
I dyno'd the car WITH the intake extension. Since we had to disconnect the neg battery terminal in order to connect the Neo I did not get a CEL at all for the first couple of hours (while on the dyno). However, I did mention this notion to the tech about the CEL when I previously added the extension; he assured that tuning the Neo "should" correct the CEL lean issue. On the drive home I got the damn CEL and brought it back to him...needless to say, he was dumbfounded. He suggested he could add more fuel or adjust the low (part throttle) to "try" to get rid of this CEL; still he was unsure. So, I told him I would check with a mechanic and see if one of my O2 sensors or MAF is bad. I called some shops and all said the same thing, I am adding more fuel to match the increased air which is fine but they told me that the Neo "probably" isn't allowing the MAF to read/monitor the increased air. The thing that really gets me is that I took the extension off just 2 days ago and reset everything (pulled ECU-b fuse and unplugged neg batt. terminal) and have driven the car all different styles (from agressive to mild) and have not been able to get the CEL. I WISH I could make this damn extension work because I KNOW a lot more colder air is coming in and I cannot even utilize it! Is is "possible" that one of my O2 sensors or my MAF is on it's way out and causing this? It is definitely due to something with this extension, there are no cracks in the extension pipe and the rubber connecting piece was secured. The MAF seal is good BTW. I am at a loss as to why this is happening.
Could it be that my car STILL needs more fuel?
Could my O2 or MAF sensor be on it's way out?
Could I still be popping this check engine code as we speak without it lighting up on my dash? If so then it might not be from the extension, it might be just a bad O2 or MAF.
Please help someone!!!
The latest,
I dyno'd the car WITH the intake extension. Since we had to disconnect the neg battery terminal in order to connect the Neo I did not get a CEL at all for the first couple of hours (while on the dyno). However, I did mention this notion to the tech about the CEL when I previously added the extension; he assured that tuning the Neo "should" correct the CEL lean issue. On the drive home I got the damn CEL and brought it back to him...needless to say, he was dumbfounded. He suggested he could add more fuel or adjust the low (part throttle) to "try" to get rid of this CEL; still he was unsure. So, I told him I would check with a mechanic and see if one of my O2 sensors or MAF is bad. I called some shops and all said the same thing, I am adding more fuel to match the increased air which is fine but they told me that the Neo "probably" isn't allowing the MAF to read/monitor the increased air. The thing that really gets me is that I took the extension off just 2 days ago and reset everything (pulled ECU-b fuse and unplugged neg batt. terminal) and have driven the car all different styles (from agressive to mild) and have not been able to get the CEL. I WISH I could make this damn extension work because I KNOW a lot more colder air is coming in and I cannot even utilize it! Is is "possible" that one of my O2 sensors or my MAF is on it's way out and causing this? It is definitely due to something with this extension, there are no cracks in the extension pipe and the rubber connecting piece was secured. The MAF seal is good BTW. I am at a loss as to why this is happening.
Could it be that my car STILL needs more fuel?
Could my O2 or MAF sensor be on it's way out?
Could I still be popping this check engine code as we speak without it lighting up on my dash? If so then it might not be from the extension, it might be just a bad O2 or MAF.
Please help someone!!!
02-08-08, 07:39 AM
#34
P0171 (Engine bank 1 too lean). I haven't gotten the CEL since I removed the intake extension 2 days ago. I might still get my car re-scanned to see if it is still running the same code; maybe it's under the radar...without throwing a light on the dash, who knows. Please throw some ideas at me!
02-08-08, 06:07 PM
#36
Lexus Fanatic
If you had a dyno sheet showing your AFR that would be alot more helpful.
Without a wideband you really don't know what's going with fuel and how to make adjustments on the neo to compensate. If you can get someone with a odb diagnostic tool to see the voltage of the 02 you can figure out what is going on. That CEL code will pop up if the voltage drops below .45v on the 02 sensor.
Without a wideband you really don't know what's going with fuel and how to make adjustments on the neo to compensate. If you can get someone with a odb diagnostic tool to see the voltage of the 02 you can figure out what is going on. That CEL code will pop up if the voltage drops below .45v on the 02 sensor.
02-11-08, 05:30 AM
#38
If you had a dyno sheet showing your AFR that would be alot more helpful.
Without a wideband you really don't know what's going with fuel and how to make adjustments on the neo to compensate. If you can get someone with a odb diagnostic tool to see the voltage of the 02 you can figure out what is going on. That CEL code will pop up if the voltage drops below .45v on the 02 sensor.
Without a wideband you really don't know what's going with fuel and how to make adjustments on the neo to compensate. If you can get someone with a odb diagnostic tool to see the voltage of the 02 you can figure out what is going on. That CEL code will pop up if the voltage drops below .45v on the 02 sensor.
02-14-08, 10:45 AM
#40
P0171 (Engine bank 1 too lean). I haven't gotten the CEL since I removed the intake extension 2 days ago. I might still get my car re-scanned to see if it is still running the same code; maybe it's under the radar...without throwing a light on the dash, who knows. Please throw some ideas at me!
09-24-08, 05:22 AM
#42
...yeah man, I'm 100% getting them and installing them right after the winter along with some "body kit work" 
. I want to wait until after the winter because I have to be good because I'm saving up for my wedding in April '09. About a month or so before I will buy those damn headers. Hopefully they yield the 17whp/18wtq that everyone is gaining, I'll re-tune my NEO and maybe I can squeeze an extra 3-5 whp...by then I will be just passed 290whp or 360-365hp (crank) estimating we have a 20% drivetrain loss. I'll keep you guys posted.
Oh, btw the CEL (PO171) that I was getting earlier for the LONGEST time (earlier in this thread) was due to two spark plugs being VERY loose (I just found that out about 2 weeks ago)!
I tightened them up...no more codes and the car runs MUCH better. My car was like that when I had it dyno tuned so perhaps the power numbers were not accurate.
Although, they could perhaps be a little better now.
. I want to wait until after the winter because I have to be good because I'm saving up for my wedding in April '09. About a month or so before I will buy those damn headers. Hopefully they yield the 17whp/18wtq that everyone is gaining, I'll re-tune my NEO and maybe I can squeeze an extra 3-5 whp...by then I will be just passed 290whp or 360-365hp (crank) estimating we have a 20% drivetrain loss. I'll keep you guys posted. Oh, btw the CEL (PO171) that I was getting earlier for the LONGEST time (earlier in this thread) was due to two spark plugs being VERY loose (I just found that out about 2 weeks ago)!
I tightened them up...no more codes and the car runs MUCH better. My car was like that when I had it dyno tuned so perhaps the power numbers were not accurate. Although, they could perhaps be a little better now.
I'll let you guys know what's in store for me with my SRT and NEO
11-08-08, 06:20 AM
#44
I have my S&S headers now but wifey doesn't want me to get them installed until after the winter. After I get them installed I too have to have my Neo re-tuned and re-dyno'd...hoping to get around 290whp or better! We'll see; Good luck GS400rcrX with your dyno as well!
