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How will i know about the right figure like the 13.2:1 Will the FPR have a guage that i would be able to read it from ? Should I still buy this FPR if I buy a CAI... wouldnt the CAI help the engine run a richer?
You need to check with a true wide band a/f meter.
So, is this saying the fuel map doesn't extend properly into this operating region or are the injectors a wee bit undersized, or what? Looks like I'll be eating some crow on this one. I've always pooh-poohed FPRs on mild cars.
What I am finding is that the MAF is senstive to intake geometry and sometimes with certain intakes the A/F ratio is off because of that. A rgulator is not as good as a custom ECU but it is cheap and it works.
if jetpilots car is stock with just a header and cai there is no way to have so lean A/F ratio. i have seen stock high octane fuel maps for our cars and up hills the a/f is even 10:1!!!
so either the reading of the dyno are wrong, or he has a device lets say SAFC to alter A/F ratio.
My car with S4s, CAI etc has a similar A/F ratio, but with full bolt ons+SAFCII, minus ECU.
You need to check with a true wide band a/f meter.
Mike
Can i buy one of these a/f meter or is it too expensive
Quote:
Originally Posted by alex29
if jetpilots car is stock with just a header and cai there is no way to have so lean A/F ratio. i have seen stock high octane fuel maps for our cars and up hills the a/f is even 10:1!!!
so either the reading of the dyno are wrong, or he has a device lets say SAFC to alter A/F ratio.
My car with S4s, CAI etc has a similar A/F ratio, but with full bolt ons+SAFCII, minus ECU.
alex29
Well i have no device attached in my car then the K&N, the header and the Remus catback... Dammit my dad is a certified Nissan/Infiniti mechanic and Nissan service manager.... he's almost retiring.. all those years working with him at home and i still know squat
This is interesting I did a simular test on intake piping for my car. Also I seem to notice that either my car is flowing alot of air or maybe there is something weird about my MAF. On average I can pull 4.64-4.68v from the maf but when the temp drops below 60*F or at nite sometimes I peak between 4.69-4.71v. So far I have cai, PS header, phenos, 2.25in catback w 2k maxima muffler, UR UDP, JWT s3's/ecu.
Where did you install the wideband, I'm assuming that an extra bung was welded to the header for the o2 right? If I could free up some power with a nismo FPR I would definitly go for.
Quote:
Originally Posted by choaderboy2
I have been screwing around with various CAI's lately. I have found some interesting things. AEM's intake works the best with a non cammed motor. PR's works pretty good on a cammed motor and makes real good midrange.
Hotshots intake had the highest MAF voltages, but didnt make any more power on engines that are cammed out and less midrange than the PR. Well I put my wideband A/F meter on a friends car and found that the HS runs on the lean side and the MAF doesnt compensate entirely for the gains in flow. The HS was putting out 4.56 volts at the fuel cut, a lot for just a bolt on motor with S4's.
Mike
__________________
91 Nissan Sentra SE-R: KYB AGX's, eibachs, prothane mounts, ES suspension bushings, addco RSB, FSTB/RSTB, CAI, JWT C2/ECU, 3in B-pipe, UR UDP, nitrous
Best ET: 13.57 @ 99mph
How will i know about the right figure like the 13.2:1 Will the FPR have a guage that i would be able to read it from ? Should I still buy this FPR if I buy a CAI... wouldnt the CAI help the engine run a richer?
Jairo,
Mike's advice is simple:
If you plan to install camshafts, plan on buying a HS CAI and an adjustable Fuel PRessure Regulator (or have a reprogrammed ECU that runs richer mixtures in the upper rev range).
If not (i.e. if you stick with stock cams), get an AEM CAI.
As for leaning out, do not be affraid. From you dyno, you are close or below 13:1 all the time. From 7000rpm up to 7500 rpm (where our rev limiter is et) you go from 13:1 down to 12-12.4:1. The peak in the AFR curve that scares you happens after 7500rpm when the rev limiter cuts off the fuel.
If you plan to install camshafts, plan on buying a HS CAI and an adjustable Fuel PRessure Regulator (or have a reprogrammed ECU that runs richer mixtures in the upper rev range).
If not (i.e. if you stick with stock cams), get an AEM CAI.
As for leaning out, do not be affraid. From you dyno, you are close or below 13:1 all the time. From 7000rpm up to 7500 rpm (where our rev limiter is et) you go from 13:1 down to 12-12.4:1. The peak in the AFR curve that scares you happens after 7500rpm when the rev limiter cuts off the fuel.
Chris
Chris,
What's up dude? hehe thanx for your explenation.... I dint not really pay attention to the graph (stupid me). I think i will keep my stock internals for now... i have plans for changing cams & ECU in the future but i think as you and Mr. Kojima pointed out the AEM will do just fine. (i will READ the graph first then ask questions in the future)
Ok lemme start saving for an AEM now
Here is my engine-bay layout (is this layout the same as the once in US? Will the AEM fit?
my apology for the huge pic
This is the way I would go too. Get the AEM. Later on (when you get cams) you may try to replace the AEM pile from the MAF to the filter with a custom-made 3 inch one and see what it gets. Just go by the pictures of HS CAIs and you will be in the ballpark.
It will be much cheaper (although probably not as good) as importing another CAI from the States.
__________________ Jonathan 94 LE "Im going to get groceries in the gas sipper" 93 G20 "Im cruising tonight" 2004 Quest "The NEW Papi Bus" To school and back in 45 minutes
This explains why I recently lost 3-5 WHP throughout the RPM range by changing from the PR CAI to the AEM. I am running S3s, JWT ECU, HS header and HKS exhaust on my 1993 Classic.
Since the AEM has been touted as the "best" CAI, I was expecting to gain 2-3 WHP.
With the PR CAI the A/F ratios ran mostly in the high 12s and slightly over 13 between 4200 and 5200 RPM (a single reading of 13.3 at 4400). With the AEM, the engine ran richer by 2-3 tenths of a point in the A/F ratio with a max ratio of 13.0 at 5000 RPM.
Looks like I will be installing the PR CAI and heading back to the dyno.
__________________
Nick McCollom
99 Infiniti G20
93 Nissan NX2000 14.027 @97.98 (N/A) I wish I had time and money again, this little car has sat for 2 years now. I do miss driving it bad. It will be back soon though faster than ever.
So Mike K. for those of us looking to fab up our own intakes, is it safe to say that we should follow the HS design as close as possible using 3" piping and get a AFPR to tune AFR. Granted we plan on or are already using cams.
-Kenny
__________________
Murfreesboro Sleeper Street Sweeper
91 SE-R--lots of mods SOLD
The Wolf
01 Jetta Wolfsburg 1.8t--APR 93/100 oct chip, TT 2.5" Downpipe, Forge 007, n75j, custom intake, votex springs
My question is this. Where are you guys with A/F meter guages getting your signal from? I do not want to tap the stock O2 sensor. I always thought about tapping a second bung in my header and putting an O2 sensor there. Any ideas?
__________________
TEAMSERIOUS 2008!
Quote:
Last edited by Shawn B : 01-16-2008 at 03:50 PM. Reason: So I could flame him harder
My question is this. Where are you guys with A/F meter guages getting your signal from? I do not want to tap the stock O2 sensor. I always thought about tapping a second bung in my header and putting an O2 sensor there. Any ideas?
the air to fuel ratios that everyone is referring to is provided by a wide band O2 sensor $$$ that is at the dyno shop. our O2 sensors are not accurate for tuning. search for wide band and you will find some interesting new portable wide band gauges (again $$$)
