chrissso

Essentially, this is diffusing the flow. Any tube or constriction is difusing the flow. It might cause alot of turbulance. Need practical bench testing to see if voltage versus flow is stable and accurate everytime. The tripping is something else I was thinking of, however, couldn't quite get my head around. It makes sense. As with the remapping, the maths will have to be done for any method of increasing or redistributing the resolution of the MAF. Resistor will not work. You can lower the voltage output, (or maybe even input to the maf) but the MAF will still only read a maximum amount of airfow. We know that through a given size of tube, the airspeed will be constant for the volume of air constantly flowing through it.Therefore we either need to increase the resolution to read a higher airspeed, or decrease the airspeed per volume of air (bigger tube). Or possible slow the air around the sensor down. This may not work however due to turbulance, and the result maynot be a linial rereprisentation of the original graph (the later may not matter) Thanks

Gavin Woods at Autoetch on the Gold coast. It's a little bit of a drive for you but they do lots of them.

What about a head gasket that's leaking a bit of oil onto the manifold?

This is one of those questions that no-one wants to answer 'cos no-one really knows enough about it. It's a hard question. There are alot of variables, aerodyamics and physics involved. The Z32 is the same diameter as the RB25 MAF, but will detect a faster airflow than the max detectable airfolw of the RB25 MAF. his gives it a higher "resolution". You cant get more resolution from the RB25 sensor, however, you may be able to bring the airspeed down so that the airflow through it is in it's readable range. Something off the top of my head is to make the tube around the sensor bigger to slow the airspeed past the sensor down. You would need to cut the sensor out of the tube it's in and glue it into a larger one. Another - put a difuser infront of the sensor. A problem wit this method is that there are a lot of variables that can change like occilating windspeeds caused by eddies that a difuser would make. These both need to be tested on a bench. A resistor wouldn't work, as it would just take from the resolution of the sensor. Can't think of anything else...

Thats correct, however, the sensor goes straight from .3 volts at 14.6ish AFR to .7 volts at 14.8ish AFR. That's why the voltage read outs from the sensor on criuse and idel flick back and forth from .3 to .7 v. The computer knows that if it continually adjusts the mixture slightly for the voltage, it knows the mixture is in the 14.7 area. So for tuning, if the narrow band sensor goes to it's voltage change, it means that you are at 14.7 AFR under boost, by which time the damage will already be done... Edit... Raising the std rail pressure and trimming down the values is usually a technique to get around fuel/ignition cut and R&R, and also getting more fuel out of stock injectors, or less fuel out of oversize inkectors, etc. All, which is better solved by a PFC.

I aggree with that. Wasn't specific enough. R&R - mine would just go great till about 4500, then just chug along...

Hey, here's some info about Dual Voice Coils. There's usually 2 x 4 ohm coils per sub. You need to present your amp with the lowest stable ohms load that it can handle to extract the most power out of it. Most amps are 2ohm stable. Some of the newer mono block and digi ones are 1 ohm and 1/2 an ohm stable. When you bridge an amp, you halve the resistance. So, a 4 ohm load now becomes 2 ohms. I you have a 2 channel amp, that is 2 ohm stable, then run your coils in series to make an 8 ohm sub, then run the subs in parallel, to make a 4 ohm load. Run this in a bridged config with you amp. The resistance is halved with a bridge, which is 2 ohms...yeay. If you have a 4 chanel amp, you can wire up the sub using one voice coil and bridge the amp to make 2 channels. This will be twice as loud. It doesn't matter that you are using only one coil per sub (heresay - please correct if wrong). I had a 4 channel amp and used 2 channels bridged to run 2 DVC subs, and the other 2 for front stage. I have a friend with a 1/2 ohm stable 1 mono amp , and he runs his dvc's in parallel, and his subs in parallel. really loud. This is more for competion, as although it's loud, the sound quality isn't great.

Hey. Just some info on how they work. Might help you detrmine if it's the problem or not. The voltage should jump from about .3 to .7v and back on idle, every half a second. It needs to be hot to work and there is a heater in it to warm it up on start. Takes approx 30 sec to warm up.

Yeah, happened here as well, ripped out the filler neck with pliers and resealed with sikaflex. Did the job well.

Hey People. I had a DFA and it did get rid of the r&r. ECU goes into an R&R mode when the AFM maxes out at 5.1volts. HOWEVER, and this is a big however, we (the tuner and I) only got around to pulling out voltage with the DFA the second time we tuned it. The first time I went, we put it on the dyno and did a run only to find that the AFR's were already close to 12.5... which is what you want, and also a little strange. It should have been way rich. We ended up adding voltage with the DFA as the more boost we dialled into the IEBC to get 11PSI (which by the way is what he recommended for standard turbos) the more R&R we were getting. It turns out that the fuel pump wasn't supplying enough fuel, even at 11psi, and the knock microphones were picking up detonation, so the ECU gave it a whole lot of R&R. Stock GTST fuel pumps never seem to have enough push and you will most probably need to replace it. I bought a Walbro off this forum and it was good. Bosch are supposedly better, but harder to fit, or a GTR pump will work as well. With your leaky hose, if you suspect it is leaking, get a corkscrew clamp. You might be better off with a brass t piece as well... Edit - fix garmmar and speling miztakes

PFC is the way to go. 11PSI of boost. Worth doing them together. The power and fuel ecomomy is good.

$350/6 points for 20 over the limit? Ouch! What State?

Hey. I had a similar inident a few years back where I was going 70 in a 60 and got the fine for 80km. I looked into it and what I got from free leagal advise was that I was speeding anyway, which is not good. I wrote a letter to the traffic office and they just said that the officer setup the camera according to specs, and blah f**king blah. In the end I didn't bother and paid the fine as I didn't really just have the money or time to bother with it. No witnesses either. What I did find is that they said I was measured using RADAR and when I looked up lissues with radar, there is a heap. For example, if there is a billboard or a truck with a big flat side panel, then the radar can bounce off it and get a reading from somwhere else. There are other issues as well. This next bit was from five years ago, and could also be a story from the USA. There was something about "judicial notice" which is something about experiments with the device and all situations where it could possibly be wrong. Apparently, the cameras don't have judicial notice and if you ask them to provide it, they have to ship a bandwagon of scientist to do all the experiments for the case. This is costly and in the end they don't bother and just drop the charge. Also, if they do have judicial notice, there that would make more loopholes for the camera. So, basiclly, if you have the time and the money, go for it, however, you might find like I did that it's not worth it. Just get your own back some other way!! Terrible but what do they expect when they rip off semi-innocent people - heh heh. Alternatively, Don't speed ever!

I think you'll have trouble getting info out of any one here for that as Skylines typically hail from JAPAN!!! [/sarcasm] Maybe you should check for a forum for importing pommy cars. Not sure what they import though, maybe mini's? Have you checked out importing from japan? Why England? Cost???

Hey, I replaced my fuel pump because my fuel pressure was dropping from 50psi to 40 on 10psi of boost and high revs. I wouldn't have changed my fuel pump if I had enough pressure, so I can only think that you've changed your's for the same reason, or you were bored and/or wanted to change you fuel pump. Because I changed my fuel pump to a Walbro, I now had 50 at full revs, on the current tune, and the afr's went rich, so I needed a retune. So, If you change your fuel pump due to a dropping pressure at high revs, then chances are yes, you will need a retune.

Hey Mcracken, get your boost set to 10-11psi. This should be low enough to be considered just below the danger limit. Of course, the choice is totally yours. You maybe happy with 9psi. The retune might get rid of the dip. Get him to check the fuel pressure on full boost..If a bit low, then back to 9psi for you I'm afraid... and a need for a bigger fuel pump!

I've noticed that at around 11, this is where the popping occurs. 11 is way to rich. 12 is considered a safe tune. 12.5 is supposedly right on, but look after your car etc. 13 is bad. Min was getting into the high 10's and we retuned to 12, the difference was well worth it, and saved on fuel too.

Spitfires are a direct replacement.. What car/engine? I'm assuming RB25 as your listing 10 psi as a mod. Do you have any aftermarket engine management? Mine had the same issues with .8mm plug and the same mods. Coilpacks were repaired, made a difference, but still mild pop. Really bad on cold nights. Got the car tuned with some aftermarket managment, works a treat! More power too. Never popped again. On researching it I found that the issue was just the mixture was getting to rich to ignite. Alot of people on here have replaced the coil packs and the problem goes, however, alot of people have also replaced coils and the issue had not go away as it was something else, like rich mixture...

Check out your other, other post.

Don't know if I can answer this for you fully, but, you can't put a ApexiPFC into an auto skyline for one reason or another. Something to do with ignition cut!?!? It's half an answer until someone else can help you... Chriso Edit;- ignition and or fuel cut on gear change.

Leak down test? It's like a compression test, but with more depth to fault finding. Have a mechanic check over it. They know stuff about cars and shit, heh heh. As for faulty parts, well, you get what you pay for. Part companies with a good reputation probably didn't get them by accident. I'm sure that reputable companies utilize technology such as ultrasound and x-ray to see where you can't, before selling you the product. And cars are like chicks, cost money. Edit:- BTW what are you planing to do? If you are upgrading the bolt-on bits, then I would definalty go and talk to a mechanic as a lot of money spent on the inside of you engine might be a set back, but might give you less heart ache in the end.

Have you got a printut with air/fuel ratios? Thad be nice..

Hmm, I'd go to the dyno and get your fuel ratios checked. Popping is most commonly because its too rich. Rich mixture is harder to ignite. Then the mixture is burnt after it has exited the cylinder giving a pop. Usually caused by the air flow metre detecting too much airflow, (usually from intake mods like fmic and pod). The EUC adds not just a littlle more fuel, but a lot more. Too much infact as it thinks the excess flow is a problem. I regard to the issue going away after the boot rise... I can't say for r34's, but with 33gtst's, it would seem that the fuel pump only supplies enough fuel for std boost. Your poping might have gone on higher boost because your fuel pressure might be dropping, and themixture is coming back to lean, or at least closer to where it should be. Anyway, there are 101 answers to this. IMO minor popping, as long as it is a minor misfire is not going to cause imidiate problems. However, if it is running rich, and you don't do something about it, then you risk other issues like cat damage and washing the bores. Best best, get it checked on the dyno and then talk to the tuner about a course of action. Most probably ECU, maybe a fuel pump. Chriso

Have you check all the vacuum hoses connecting to the plenum?

What do you mean? Cos the first porka was a vw taken apart and put back together with a bit of extra love and care by Mr Porka..