Robert

Im reading myselfes to death in this "cyl5 thread". Someone should moderate it and add a conclution in the end... zzz

Hi, well actually you can get a long way without connecting it, the IAT temps dont get very high with an fairly efficient intercooler.. the reson I have not connected it yet is simply that Ive been a bit lazy But how can heat shielding and exhaust wraping help me? If you have some good tips and ideas there, Id love to hear them! This is car is built for track days, not drag races, so I need to get this knocking out of the way :

Great, thanks, I though the megasquirt (or me) was going insane

Hi, Im currently tuning my L24E turbo engine. Stock engine with a std turbo manifold, T04E turbo with .63 exhaust house, 3" exhaust and intercooler.. Now, when tune my cars (on road), I generally empty 2nd and 3rd to tune the high RPM range (datalog tuning).. But in later stages of the tuning, and when Im fine tuning the ignition map, I generally empty 2nd, 3rd, and if that works great I do it a couple of more times just for the extra data.. But what I found is that when I come to 3 gear for the second time, I get SEVERE knock! I did not put to much to it, but It does not look like its a timingAF issue.. So my question for the L experts is if there are any parts on the cyl head that get hot enough to cause severe knock in just a couple of hard runs? I didnt put to much time in tuning it away like I said, but retarding the timing didnt help much.. My next move is to connect the intake air temp sensor and see what that can tell me. If the temps rise enough, Ill try a air temp timing retard.. Oh, timing is currently 36 degrees at WOT (0), and ~8 degrees at ~24 PSI (260 KPA) where the knock takes place. Dont suggest the following: Spark plugs are cold. AFs are high 11s I have a intercooler Engine coolant is ~85 degrees C And for everything good in the world, dont come with "let a company do the tuning" stuff, lets stay on topic.

I think we can conclude that we have different opinions. I thrust grease and motor oil on my gaskets, and on all the different engines Ive built over the years, Ive hardly ever had a leak. On my latest L24E with turbo build, all gaskets got oil and grease, no leaks. The surfaces was only cleaned and grinded with some ~600 paper.

A little update here: I replaced my fuel filter, and clamped the fuel return pipe a little (to increase the base pressure in the rail). Also i opened up the "IN" pipe where the hose is clamped on, cause theres a smaller diameter on the pipe there. So, I took it for a drive, and the first thing I noticed was that It was close to impossible to start! Good sign.. Further on the AF ratio was a bit richer than normal, about 0.5-1 AF value lower I would guess. Unfortionatly my computer was not in the car, so I had no possibility to tune it, but I emptied a few gears, and the AFs, that earlier went up to 13s on 5000+ was now down on 10s! Now I dont know how much extra pressure Ive applied here, but the injector CCs dont grow too much on higher pressure.. Also the fuel filter could have been clogged a little, and the narrowing on the "in" pipe probably restricted flow a little. All in all, I think I got a little here and a little there. Im going to tune it tonight and hope to get the DC down to 80s, or at least 90s....

Agreed. Any parts with bendscracks and so on can cause these issues. Also, a bended head typically causes problems on the center cylinders, 2-5, and especially 3 and 4.

Like I said this is based on experience. A quick example is once I mounted a thermostat gasket dry, and it leaked. Some grease solved it. I dont know the theory. Pee on your gaskets all you want

Well, If youre such an expert, you tell me. More seriously, this is simply based on 10 years experience. Ive had several oil and water leaks where I simply greased or oiled the gaskets, and the problem is gone and never returned. Feel free to mount any gasket dry, I dont care, and you and all others can say whatever you would like, this is simply my experience, and probably many gaskets can be dry mounted, but I dont see the reason to take the risk. I dont know the Theory, but adding grease or oil cant hurt anything in my opinion, and in my experience It can make the difference of completing the race, or ripping your hair out in the Pit. Oh, and Im shure different gaskets need different mountings to.

Still, If the head is straight, it takes A LOT too break a head gasket, and if its a Nissan gasket, they handle A LOT in my experience. Unless theres a Whooole lot of HP in there, or SEVERE detonation, I dont think detonation is his problem....

Thats a good old way tested and retested. An interesting view on hot parts from mr rolling parts, but Ive always used engine oil on turbo flanges without problems...

? Its my third 255, never had any issues, until maybe now!

In my experience, Nissan gaskets are bullet proof. A L24E stock gasket can support 300+ hp with detonations (tested and retested!) Is your cylinder head straight? 100%?

On oil gaskets, simply use some engine oil (new unused). This makes them seal great! On water gaskets, normal grease works great. Thats how I do it. Do NOT mount them dry!

Probably yes. If It delivers enough to pulse the lines at Idle, It probably does at cruising as well. The AFM can be tested with an Ohmeter (search the forumweb), but the easy way is to borrow one and just try If thats possible.. Sometimes you can measure a AFM, and it looks great, but once its in duty, It starts acting weird again. Also, check that the movable parts is not stuckslow and that it returns when you push it..

Ill try to get a gauge that I can hold up to the windscreen. That way I can see If the pressure drops at high RPMs. If so, the pump probably needs to be replaced...

Hi. Such small pressure drops should not lower the injectors to much, but lets say 400cc.. This still gives me an extremely high BSFC if my "seat of pants" ~300 BHP is correct. I could do a drag with a 300BHP car just to test though. I did some diagnosis last night. I changed my fuel filter so theres no braking there, and I clamped the fuel return pipe on the rail to increase fuel pressure. Im going to take it for a test drive today and see if I can lower the dutycycles a little now. Ive also E-mailed Topendperformance, and they, like you, claimed the stock rail handles 350hp easy. My only conclusion is that either the pressure regulator dont raise the pressure enough, or my walbro pump cant handle the demands. Thanks

The AirFlowMeter could cause rough running as well. Man, youre out of luck on this car If all those parts have broke in a short time.. Fuel pumps generally work or dont, sometimes they get weak, if thats the case, then the more you open the throttle, the worse the problem gets. Feel the fuel hose just before the rail. There should be small pulses in the line at idle. Id have a look at the AFM.

Hi, I have a L24E that Ive turbocharged and Megasquirted with 440cc supra injectors. I do have a problem though, cause at what I think feels like about 300BHP, maybee a little more, the injectors are maxed out, and the engine screems for more fuel!! Has anyone done 300+ BHP on stock fuel rail before? My setup: L24E stock internals T04E turbo .63 exhaust 3" exhaust Intercooler Stock fuel rail 440CC injectors - Should support 400+hp Walbro Fuel pump Stock fuel pressure regulator (should be 1:1) Megasquirt 100% DC @ 5000+RPM Approx 300BHP

Well, 440CC (~44 US LB something, hehe) should be enough fuel for my application in theory... Im going to check the wiring to my fuel pump, as well as mounting a aftermarked fuel pressure regulator. Increasing the idle pressure doesent help very much, but 4bar was actually my exact thought! Also, Ill go from injecting all 6 injectors simultaniously twice, to once, giving a whole ms extra of time to squirt. Hopefully these mods will bring me down to 90 %, and maybee even lower. Though, I am thinking of welding an extra injector with dual map If Im still in trouble.. I was hoping for a bigger camshaft to, so maybee Ill just have to sell the injectors and get some ~600`s... I never thought the L24E would need that much though...

Hi, Ive got a L24E that Ive mounted a T4 turbo and megasquirt on. Im having problems with the injectors maxing out, and my question is, is the NA FPR 1:1 under boost as well, or will I need a new FPR? Mod list for those curious: Stock L24E 25PSI boost Supra 440cc injectors walbro 255 fuel pump Intercooler Upgraded clutch T04E turbo Performance is GREAT!

Ever heard of a Nissan Laurel? Well, heres one with a turboed L24E, stock internals, HKS 2mm head gasket, planing ~22 PSI of boost, and ~300BHP+. Engine management is Megasquirt II V3.0, ESAB no slip differential, cut coil springs, racing slicks for track events. this is a budget build, and total build cost including the car is approx 1300$. Its not finished until the end of the weekend, this is the "so far" pics. The car will be a road car, but the main point of use is track days. Debut will be next weekend in a drag racetime attacktop speed weekend track day. I hope to empty 5 gear with ease, approx 140MPH, and to outrun many Silvias300ZXskylines both at drag and time attacks, cross fingers and toes Future upgrades is coilovers and better brakes.

The TPS has no influence on fuel amounts in practicly any FI system, except those systems without a load sensor (MAP or MASMAF sensor). But the AFM SHOULD be the main source of calculation in fuel amount at ANY RPM or load. A preset table sounds like crap. By the way, Top end performance claim the cam should work. Also, Schneider says they never heard it does not work.. Im so lost right now, I really want to try though....

So Ive heard, but noone has any details, hehe;) This is a 1987 model, so hopefully it has some upgrades. As long as the AFM`s signals are multiplied all the way, there should be no problems...

Interesting. If Nissan used Licenced Bosch injection systems, then I can believe its crap... Ive searched the web for hours now, but cant find anything except this post that tells me the AFM max out.. I searched Wikipedia, not the most reliable source of info, but they claim the L24E was produced from 1977 through 1986 in 810s, skyline, maxima and laurels -- http://en.wikipedia.org/wiki/Nissan_L_engine#L24E . If you are correct, I could be in trouble. Ill start a new thread on the subject, in an attempt to find some more info..