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Discussion Starter #1
I was running 15.5s the whole day with consistently bad launch. But what I'm concerned with is the terrible trap speeds. I was getting consistent high 86.xx and 87.xx mph. Two years ago I was able to do consistent 88mph at slightly higher temp too.

Two years ago, I had PR CAI, HS header, UR pulley, 18* timing and I did 88mph, Mobil 1 synthetic 0w30 and MT90.

Now I have the addition of Greddy Catback, bored and high polished maf, high polished TB, bypassed TB coolant line, , Ghetto ground wires, Konig Helium 10.9lb rims vs stock 17lb rims, Kumho Supra 712 195/50(lightest tires for the size), 50lb of weight reduction excluding weight savings from rims.

I got 30k miles and just changed the fuel filter and cleaned the air filter before I made the run. What do you guys think is wrong with my car? With this type of mod, what kinda ETs and trap speed should I be getting? I was expecting 14s.
 

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Weird... mabey because your car is 2 years older?? /shrugs no idea on that one lol.
 

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Jah Rastafari
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Your problems are this.

#1 Stock Nissan wires are the best wires you can use. Whatever you put on there is not even as good as the stock Nissan Wires.

#2 I bet you put on the bored TB and did not match port the intake for the TB. This is a real no no. If you do not match port the intake for the TB then you will get massive turbulance because of the lip that hangs into the track of the TB. This mod is your biggest problem of the 3.

#3 You do not put bored MAFs on cars with out recalibrating the ECU for the MAF or coming up with some type of fuel inrichment setup. If you put a larger bored out MAF the comp does not know if the MAF is bored out so the car will run leaner.
 

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Discussion Starter #5
Andreas Miko said:
Your problems are this.

#1 Stock Nissan wires are the best wires you can use. Whatever you put on there is not even as good as the stock Nissan Wires.
I did not replace the stock wires. I just added my own Ghetto hyperground kit.

Andreas Miko said:
#2 I bet you put on the bored TB and did not match port the intake for the TB. This is a real no no. If you do not match port the intake for the TB then you will get massive turbulance because of the lip that hangs into the track of the TB. This mod is your biggest problem of the 3.
The TB is not bored, just a chrome like polish. I just like to polish everything in the intake system. I even polished the inner surfaces of the cai.

Andreas Miko said:
#3 You do not put bored MAFs on cars with out recalibrating the ECU for the MAF or coming up with some type of fuel inrichment setup. If you put a larger bored out MAF the comp does not know if the MAF is bored out so the car will run leaner.
The bore is small, only 2.5mm and it ran real fine after I did it. My purpose of boring it was to lean it out a little.

What kind of et or trap speed do you think I should be running? What could be robbing me of power? I spray cleaned my TB and IM many times and each time I have to lower the idle screw to compensate for the higher idle. Now at the lowest setting, it's at 950rpm. Could the TB cleaner damage any sensors in my car which might cause me to lose power? Thanks bro.
 

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You like that, dontchya?
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The bored MAF is killing you. I know because I bought an SE-R that I later discovered had a bored MAF and it is slower than other SE-Rs w/ similar mods. It's not a good mod without the proper ECU tuning.

Did you know that the flow rate through an orifice is proportional to radius to the FOURTH power?? Increase your radius a little and you will have a big change in flow rate. You are running too lean my man.
 

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Discussion Starter #9
AntonioG said:
The bored MAF is killing you. I know because I bought an SE-R that I later discovered had a bored MAF and it is slower than other SE-Rs w/ similar mods. It's not a good mod without the proper ECU tuning.

Did you know that the flow rate through an orifice is proportional to radius to the FOURTH power?? Increase your radius a little and you will have a big change in flow rate. You are running too lean my man.
Actually, when I gteched it, the bored maf actually helped me alot. I even felt the increase in power especially in the low end. The slight increase in radius doesn't really improve air flow but the polished smoothness does.
 

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99SE-L said:
The slight increase in radius doesn't really improve air flow but the polished smoothness does.
Either way, if you increase the airflow there you are changing the relationship between airflow through the body of the MAF and the sensor hole of the MAF, and not telling the ECU how much to compensate. Maybe you are only a little leaner and its ok, but how do you know? Have you measured the A/F ratio sometime?

It would be helpful if you could dyno the car in its current condition.
 

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You like that, dontchya?
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99SE-L said:
Actually, when I gteched it, the bored maf actually helped me alot. I even felt the increase in power especially in the low end. The slight increase in radius doesn't really improve air flow but the polished smoothness does.
Well, either your g-tech is wrong or the timers at the track are wrong. You're trapping very low for your mods. What are your traps according to the G-tech?

Also, increasing radius has a much greater effect in increasing flow than polishing the surfaces. It's physics - fluid mechanics actually. You are definitely running leaner than you have before. Maybe too lean. You just don't have enough fuel for the air going into your engine and that's why you may be losing power.
 

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Air filter cleaner masta
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Your MAF is the problem. Take your maf out and put in a stock one at the track. I am sure you will be around 89mph or higher. I am suprised your car runs with that bored out. Good luck
 

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Discussion Starter #14
AntonioG said:
Well, either your g-tech is wrong or the timers at the track are wrong. You're trapping very low for your mods. What are your traps according to the G-tech?

Also, increasing radius has a much greater effect in increasing flow than polishing the surfaces. It's physics - fluid mechanics actually. You are definitely running leaner than you have before. Maybe too lean. You just don't have enough fuel for the air going into your engine and that's why you may be losing power.
I g-teched before and after the bored and polished maf to be 0.2 seconds faster in the 0-60mph. The g-tech is real accurate btw. I only increased the diameter by 2mm which really isn't a big deal. My intention was to lean the a/f ratio slightly. Lean is mean. Stock runs pig rich anyways. BTW, I just checked out my spark plugs and they show no sign of the car running rich or lean. Still looks good after 30k miles.

The weird thing was I did a compression test and all the cylinders were at 200-205psi. That's extremely high for a usdm motor. I cranked it like 10+ times until the needle wouldn't go any higher. Not sure if that's the correct way to do it. I used a brand new gauge I bought at Kragens and not sure if it is really accurate. What kind of compression are you guys getting?
 

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Air filter cleaner masta
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2mm is enough to do what you want it to do, but the problem is that your cars performance at the track got worse. I think you should get a stock maf and run it to see what it will do. I know 2mm is not a lot and it does run a little lean, but try both and see what happens. Those compression numbers are pretty high. Good luck with your car and I hope you find out the problem so you can get into the 14's!!! You should be able to pull that off with the mods you have! Let us know how it goes!
 

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Im not a eliever in the nored MAF thingy.
Find a stock MAF or borrow someones and run it again.

What size exhaust pipe are you running?

Switch to a WAI. :)
 

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Discussion Starter #17
SmoothDaddyFig said:
Im not a eliever in the nored MAF thingy.
Find a stock MAF or borrow someones and run it again.

What size exhaust pipe are you running?

Switch to a WAI. :)
60mm Greddy which is 2.4inches. I tried taking off the cai extension and the car ran noticably slower especially in the top end. From what I've read on the forums, I think for a lowport, a cai is better but there are a lot of contradicting oppinions from the highport guys.
 

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Discussion Starter #19
RedB14SER said:
it could be that your clutch doesnt grab as good as it used to since it is 2 years older.
true, that's what alot of people told me but I can still do burn outs and chirp second gear. It seems like the clutch is working fine. How can I tell?
 

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70/30 Racing
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99SE-L said:
I g-teched before and after the bored and polished maf to be 0.2 seconds faster in the 0-60mph.

The weird thing was I did a compression test and all the cylinders were at 200-205psi. That's extremely high for a usdm motor. I cranked it like 10+ times until the needle wouldn't go any higher.
i got 195-195-190-195 on my 98.

did you remember to unlpug the fuel pump before doing this? fuel in the cylinder will make some higher compression numbers, as it doesnt compress like air.

and 0.2 faster to 60 doesnt mean you have more power. 0-60 isnt a very good example of how much power a car has, as traction, etc is just as important. trap speed is a better example of engine power.

ditch the bored maf man, i have got my car to ping on pump when it was all motor on the stock ECU. you would hate to see your motor blow up, ****.
 
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