SleepingTalon

Does anyone know any place in AU I can get quality used parts? Someplace I could get some knock sensors from? I found them new, but they are $450AUD EACH!!!!

Oh, sorry. I thought you had seen the previous posts. Yes, it's an RB25.

The car is a 5spd. The bottom end is a Wiseco/Eagle Combo, and it's in a 1998 240sx. The motor is great, I can't say enough good things about it. If I put more injector, and throw more boost at it, it should be at around 550whp. The cams are definitely running outta breath for just having boost, but that problem will be addressed shortly as well. I've got an old video of it making 450whp, and drifting, which is from the previous tune (back when we were having "spark" issues), and another video of it at the dragstrip with the NEW tune. Lemme know what you think. Thanks again guys. This forum has been a TON of help! OLD TUNE, 450WHP DRIFT http://www.youtube.com/watch?v=Vjh4JN-ihM8 NEW TUNE, 500WHP DRAGSTRIP

I'm looking to get new knock sensors for my RB, any idea where to get them? I'm in the USA, so I'm assuming I'll have to buy from overseas, so any help would be appreciated. Thanks!

I just thought I'd give a quick heads up and update some of the stuff from my previous posts. We took the car back to the dyno after fighting what we believed to be a misfire problem. We hardwired the coils, hooked up an HKS Twin Power DLI, and rechecked the plug gap, but still had no luck. Then I figured out that the AEM boost cut was set too low! So all that for nothing, lol. Anyway, we also hardwired the fuel pump because we had a voltage loss going to the pump, so that fixed that problem. With the car getting proper fuel, and no boost cut (or imaginary misfire), we layed down 500rwhp/372rwkw and 420rwtq/313rwtq @23psi. We're still running a bone stock head, just ARP's, and headgasket for the increased boost. I'm not sure what the limit of the stock cams are on a non-nitrous motor, but we'll soon find out. The 550cc injectors are officially maxxed out, so it's time for some 750's, and then we'll crank the boost up to 28psi to see what it makes. We took it to the track and it ran 11.01 @128mph, so it was a pretty solid setup. This is also in full street trim, including a body kit, and a stereo system with XM sattelite radio! The car will be on the cover of S3 magazine in March, so check it out if you get a chance. Thanks to everyone on here who gave help and suggestions. It really did make life easier 8-) We're not done yet though. We've got more to come...

Before I begin, I'll just say that I've searched the forums all over the net for days now, and have addressed all the possible issues that might cause this, and still no luck. I've tried swapping coils, gapping the plugs tighter, hardwired the coilpacks, replacing the ignitor, added HKS Twin Power Ignition DLI, looked for boost leaks, and the list goes on and on....NO LUCK! If I run more than 21psi, I get a misfire, less and it's ok. What else could this possibly be? The mods on the car are as follows...GT35R w/Tial 38mm WG, built shortblock, Nismo AFPR, Walbro 255 FP (Hardwired), Nismo 550's, AEM EMS dynotuned. The car has a PERFECT tune in it across the board. It's running 11.6 A/F at WOT, and the partial throttle is perfect. It's also running speed density, so no more MAF in the car. It has 3.5 bar AEM sensor, with IAT sensor. The car is making good power, right at 450whp on 22psi with pump gas (93 octane in the US). I'm not sure what else to do. Are the stock coils up to the task of 21+psi? Are splitfires any better for sustaining higher boost? What else could possibly cause a misfire like this? I've even put C16 race fuel in the car, as a shot in the dark, to see if it would smooth it out, but still nothing. Any help would be greatly appreciated.

If the oil line is too big, then it could be blowing the seals out on the turbo. Check and make sure the correct feed line is on the turbo, if not, then you might have gotten a turbo that wasn't in as good a shape as you were lead to believe.

Well, I've used the Dynodynamics dyno here as well, and the figures on every car I've used there are identical to the Dynojet. Dynodynamics has a load control, so that will skew figures when you adjust it. 10.5 is a full point below where I'm at right now, and would be pig rich. The injectors are at 80% duty in my internal logs. I've actually made 580whp on a 4cyl with 650cc, so I'm fairly certain of where I'm at right now, but I know I'm gonna need some bigger injectors to get the numbers I'm looking for. The reason the fuel pressure is low is for low throttle tuning, and daily driving. Lower fuel pressure takes away from the max duty of the injector, while effectively making the driveability better, while higher fuel pressure does the opposite. I never run higher fuel pressure unless the injectors are starved during WOT. I'm not seeing much knock at all with the way it's tuned right now. The motor is in a 240sx, so it's being used as a drift car part time, as well as at the drag strip, so that's two different tunes for 2 different types activities. The numbers above were "hot shot" numbers, as it's at 19psi on the street right now, which is 425whp or so. Also, I target 11.5 on 4G63's, and 10.5 on Subaru's because EJ's are detonation happy, and 4G's just have sensitive knock sensors, that's all. It's been that way since the 95+DSM, all the way to the present day Evo's. Makes it hard on us tuners, lol!

Actually, 550's should be enough to make roughly 500rwhp. The fuel pressure is 38psi, so that the low portion of the fuel map is more managable. If I start to see the injectors run out, I'll bump the fuel pressure up some. The plug gap is .026, so it's very tight. As far as the turbo is concerned, I've made much more on the same turbo (give or take 570+awhp, on Evo's), so I've got a bit further to go. I've also made over 600whp with one Walbro, as it's a 255lph, not the 190. Also, AEM has internal logging, and the knock sensor on this car is not like many other cars I tune, as it shows "spikes" for engine noise, and exactly when it happened, ie what rpm, map pressure, etc. AEM is very complete. I just wanna know what voltages others are tuning around, so I know if I'm "too" safe tuned, or if I have room to play. On a side note, it's definitely the spark blowing out, not valve float. I know that for sure, but I'm glad I know not to run anymore rpm until I get a set of valve springs, that's for damn sure! I don't have the dyno plot with me, but the powerband was VERY similair to the HKS 2540 that was on it previously, except it makes about 75+whp more with the GT35R, and the power/tq doesn't fall. It makes 19psi by 4000rpm, maybe sooner. I'll doublecheck that when I get to the shop tomorrow. Thanks for all the input guys, I really do appreciate it.

7200rpm is stock rev limit, if I'm not mistaken, so that's what I've left it at. I was thinking of bumping it up to 7500rpm, but now that you told me that "valve float" is a possiblity, I'll think I'll pass on that one! I guess new valve springs are on the horizon then. I did have one question though, what kind of knock voltages are people seeing? I noticed that the sensor on this car doesn't really give constant noise, but it spikes instead. I've got the knock threshold pretty low, and it's SUPER safe tuned, so I was just wondering what voltages others are tuning to, when tuning around the knock sensor.

That's not a bad idea actually, but seeing how I have the AEM EMS, I'd probably use the AEM CDI, as it plugs right into the ecu, and it controlled by the AEM software. Of course I could just go all out and use the same CBR coils from the race car! 8-)

I'm not looking for gains with the split fires, just to fix the misfire at 23+psi. However, if the split fires are a waste of time, then I'll avoid that all together. The gap is tight on the plugs, so I know it's not that. I've got an HKS Twin Power I can use, as well as hardwire the coilpacks, and that may remedy the problem. Other than that, am I where I should be power wise at that boost level, given the setup? Thanks again.

I wanted to get some opinons on this setup that I just got finished tuning. I'm trying to see if I'm on par with people who have similair setups, so let me know if I'm off my mark so far. Here it goes... RB25DET 465rwhp/347rwkw at 21psi on pump gas (93 octane in the US) Stock head, stock cams, stock intake manifold. Wiseco Pistons, Eagle rods, custom headgasket 550cc injectors, Nismo AFPR, Walbro 255. GT35R (.70 compressor and .63 A/R) w/Tial 38mm WG Greddy FMIC Custom side dump exhaust and wastegate dump AEM EMS The car can make MUCH more power easily. The coilpacks weren't liking the higher boost, so it's time for Splitfire's I guess. Is there anything else I need to lookout for, upgrade wise, at this power level? The goal is 500whp on pump gas, so if anything else NEEDS to be upgraded to get there, the info would be greatly appreciated. Thanks ahead of time!

465rwhp/347rwkw at 21psi on pump gas (93 octane in the US) Stock head, stock cams, stock intake manifold. Wiseco Pistons, Eagle rods, custom headgasket w/ARP's 550cc injectors, Nismo AFPR, Walbro 255. GT35R w/Tial 38mm WG Custom side dump exhaust and wastegate dump AEM EMS The car can make MUCH more power easily. The coilpacks weren't liking the higher boost, so it's time for Splitfire's I guess.

What is everyone using for input/output settings on their safc w/ the z32 afm in place? Is In-2 and Out-4 correct...? Also, what is everyone using as the input/output setting with the factory afm? Just curious. Thanks!

Well, it's like a misfire. So Im not sure what that could be. The plugs are tightly gapped, and the only thing I can think of is that a coil could be going bad. Any ideas of what that "bucking" or "miss" could be? I wasnt sure if the car would do that if the AFM just started missing "airflow counts" or what it would do.

Car is only making 290kw, and running low boost. What's the limit of the stock AFM?

The car has 550's with the SAFC. I get 5.2v on the SAFC, and it hits near 100%. What's the stock AFM good to? Any other ideas other than that? Thanks again.

Has anyone had problems with tuning with SAFC at power levels of 300rwkw or more? That's about where I'm at right now with this thing, but I need to be able to run more boost. Bad coils are the only guess I have at the present moment, so I'm at a loss. It's pretty much a misfire, but at very low boost levels. Anyone else experience anything similar with their car?

That happened in the first motor we had before we found out the ringland was cracked on the piston. Infact, we were making roughly the same power too, and the car would still pull and idle find. It didn't even seem as though there was an issue at all. I would go to a leakdown or compression test immediately.

I've got a weird issue with the rb25det Im running. The motor was just rebuilt with wiseco/eagle combo, and arp headstuds, with cometic gasket. The car is running an HKS 2540. When the motor was stock, before the rebuild, it was running 19psi (1.3 bar). With the rebuild on the car, if I try to run more than 16psi (1.1 bar), the car will "buck" and "breakup" all the way through the powerband. I would like to run UP TO 22psi (1.5 bar) on race fuel. I tried putting in race fuel thinking that it could be engine knock and timing getting pulled, because on the dyno plot, as soon as the higher boost level (more than 1.1 bar) comes in, the the car not only "bucks" but the power immediately drops down like the stock ecu is pulling timing. However, even with the C16 (117 octane) it still did the same. The car is making good power, even at only 1.0-1.1 bar, but I wanna run more boost. I've checked the plugs, and they are fine, and tightly gapped. I've also checked for vacuum leaks, and the system pressure tested fine. Could a bad coil cause this...? What else could be causing this problem? Just to let you know, Im using SAFC and adjustable fuel pressure regulator for fuel control, and the air/fuel ratio is perfectly flat at 11.8. Any ideas or suggestions would be greatly appreciated. Thanks again!

The AEM is the system I use in almost every car here in the states. It has the most flexibility of all, and the software updates have fixed most of the "gliches" that it had in the begining. You thought the aem software was "clunky?" Im confused...the AEM has the best interface of any system I've tuned with...3D maps, and tables, so you can "see" what you're doing for those like myself that dont like to stare at tables and numbers constantly. Boost comp doesnt always work well with every car, but it does come in handy. As far as the knock control is, it does come in handy, but for cars with very sensitive knock sensors, you pretty much have to shut it off if you wanna make BIG power. Take the new EVO for instance. If you have the knock control on, you'll never make big power, but for a street car, I always turn the knock control on. Also, to answer your question, the AEM has a coolant offset table for cold starts, so you can set the table up to gradually pull fuel out as water temp increases. At any rate, the AEM is what I consider the EMS yardstick now. It can do everything very well, and pretty much has the bases covered. The antilag system is still primitive compared to other systems, but the Supra that the shop I tune at built, is running the AEM, and running 8.5 on street tires and stock piston rings with it! So it does do the job very well. I havent had the chance to use the PFC yet because it's not a product that is readily available or of much use for the cars here in the USA, but I will be using one soon, and I'm anxious to see how it compares to some of the other systems I've used...and I pretty much tune anything and everything that comes my way!

I think I paid $1800 for the Giken through my shop. If you want, I can check for you but it'll probably be Monday before I know with it being the weekend.

OS Giken would be my suggestion. I've been using the Giken twin disk in my 4G63 drag car that's making 485awkw, and running mid 10's, and it's been great. Be weary of "carbon" claims, as many of them aren't actually carbon on carbon, but carbon on metal. The thing with carbon is that it's gotta be heated up before it'll grab. They usually slip when I'm tuning them on the dyno, until I put some load on them, then they grab very hard. They multi plate assemblys will let you slip them very well and keep the abuse off the rest of the driveline, that's the biggest advantage. On a side not, a TRUE carbon clutch, like ATS, or Tilton, will be extremely costly...like $5k US Dollars. There are some you can find for as "cheap" as $3500 US Dollars, but as far as Im concerned, that's still not cheap by any means!

Eagle rods are considered an entry level rod for people that arent gonna break the 450kw barrier. I've made about 440wkw with Eagle rods, and they were fine, but I still dont 100% trust them. Crower rods are very strong, but also much more expensive. For the price of crower rods, I can use aluminum rods that will be MUCH lighter, and handle more than twice the power. The aluminum rods we use are very trick. They have a dowel pin that holds the bearing in place and keeps it from spinning. It's a very nice piece. If the GTR rods will handle 350-400rwkw, that's all I'll need. The turbo on the car cant even make power that high, so it's just precautionary. I'm also gonna need torque specs for the ARP headstuds, and ARP rod bolts. So if anyone has the correct information, that would also be greatly appreciated.