Tony240ZT Posted May 29, 2002 Share Posted May 29, 2002 Guys, when I drive my car hard things heat up pretty quick durring the day. The temp gauge starts going to the right of the center mark and the boost doesn't do as much good as it did when the car was cool (had to turn back timing to compensate for this ). Currently the car has a single electric fan behind the radiator, a 3 core radiator, new rad. cap, B&M oil cooler. I don't have an intercooler, and have my air filter behind the fan that is peeling off the hot air from my radiator. The temps here are starting to get into the 90's, so here is what I have been planning: It's a starion intercooler, I'm putting the air filter out front, and have gotten some pretty good sized fan and am thinking of mounting it in front. The question I have is is this new fan going to help any? I already have a pretty good fan pulling from behind: As you can see it is over to the driver's side more than anything. Do you think I should move my oil cooler out of the way and mount the front fan more to the passenger side? If I do that I'm not sure where to put the oil cooler, maybe infront of the fan? Should I run both fans at the same time? If not is there one that I should run before the other? I really wish I had more room behind the radiator to install two cheap electrics behind there, but I can't find a low enough profile fan in the junk yard to do that. Has anyone moved the L6 engine mounts back? Not just for more room, but for better weight distribution? Thanks for your opinions. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted May 29, 2002 Share Posted May 29, 2002 One thing I would recommend is trying to find a 81-83 turbo radiator that is in good shape and put it in your car. I have the stock radiator (turbo) and a 16 in electric pulling air, and it is doing a good job of keeping my engine cool, with an AC condensor and intercooler sitting on front. If you have a good contact at a radiator shop, they could cutom make you a new radiator. Just because it is a 3 row, or 4 row doesn't mean it can cool your engine. I had a 4 row from Motorsports that would not keep my engine any cooler than a three row. It is more about the design of the core. More tube and fins are the way to go. That is the diff between a turbo versus non turbo. You could always get an aluminum one and be done with it. BTW< the Starion intercooler is pretty restrictive. I would see about getting a better one if I could. Lots of pressure drop. Good luck. Quote Link to comment Share on other sites More sharing options...
z-ya Posted May 29, 2002 Share Posted May 29, 2002 Hey Tony, I would think that with the radiator you have, and the electric fan, you should be all set cooling that L24ET. What is the CR by the way? Also, at what temp does the fan come on? Are the oil cooler lines getting hot? I'm running the stock 240Z radiator, a Mr Gasket fan (the highest flow rating I could get that would fit), a Spearco intercooler, and an oil cooler. I've sat in traffic with ambient temps over 90deg F and have not had problems. The fan runs almost continuously, but the engine temp does not go over 200 deg F. Maybe a good flush is in order. Pete Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted May 29, 2002 Author Share Posted May 29, 2002 Lockjaw, I'm only looking to make around 250hp, I think the starion will be okay for that. It will be at least better than nothing. This car is made from junk yard parts and parts I have laying around. My `72 is more of a serious monster, but is also a money pit! Notice the HKS FMIC, TRD parts, and stand alone EMS Pete, stock L24 short block, P90 head, L28 felpro gasket should be 7.56:1 CR. I guess stock L28ET CR is 7.38:1. Both CR's seem pretty low to me considering that most people building really high performance turbo engines have at least 8:1. I think with the single fan setup I was only pulling accross 1/2 of the radiator. This radiator used to keep the carb'ed setup with the manual fan/shroud super cool, the needle would only come close to the middle mark, but never go accross. Currently I just have the fan run at all times. I'd like to install a thermal switch, maybe I'll install a couple and setup the fan(s) to have 2 speeds. I'll probably use the thermal switch that is used to turn on that fuel injector fan to run my big fans even after the car is shut off. It seems to take a lot of heat to turn that switch on. I don't notice the oil line being much more than maybe a couple degrees over ambient. The feed line and return line feel the same temp. The lines are pretty thick. Has anyone found any interesting info by taking the oil temperature? If so where's a good place to take the temp at? Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted May 30, 2002 Share Posted May 30, 2002 A turbo charger adds heat to your system. I low compression engine is much more inefficient than a higher compression engine. Those two factors alone could contribute to your issues. As for the intercooler, as long as you are happy, I am happy. I just wanted to let you know you will have a nice pressure drop accross the core. Prob less if you have the inlets and outlets enlarged. Another thing I would check for is retarded ignition timing. My frieds 455 from long ago ran really hot with retarded timing. Long shot I am sure. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted May 30, 2002 Author Share Posted May 30, 2002 Timing is advanced as far possible without detonation when the car is hot and under load on 91 octane (it's all we have here). I think the base point is something like 18 degrees. I'm putting 2 1/2" end pipes on the intercooler. I'm pretty sure I have the more modern type where they upgraded it a little. Other junk yard IC's I would consider would be MKIII Supra T, or Volvo 740 T, but I'm not sure that either are much better. I think Scotty has done pretty well getting into the 12's with the volvo IC and stock turbo, I've heard the supra one has real bad presure drops and from looking at the one on my `87 Supra it's easy to tell why, the end caps look all jagged. I guess even a mid sized NPR IC would be a good upgrade. When I have a few extra beans I might just get one. Picked up some 3" aluminized steel pipe today and went away fabing up the cool air intake system.: Required a little bit of cutting up front, but nothing major. Left pleanty of room to run the intercooler piping above it. Found a smaller fan for the driver's side so that I could run IC piping over it. Hopefully I can find someone to help with the IC end pipe welding tommorow and get on the road again. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted May 30, 2002 Share Posted May 30, 2002 Aaahhh those 30 year old electrical gauges... Hey Tony, might be a good idea to hook up cheap mechanical oil pressure and water temp gauges. I have a cheap Pep Boys pair in both of my Z's and they'll give a more accurate reading of what is going on. I think you can get the pair for < $30. No sense forking out the big bucks since this your JY motor Mike Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted May 30, 2002 Share Posted May 30, 2002 Sounds like you have a plan. I would hunt around for a used turbo rad, and if you find one, I will bet you money that will solve your cooling issues. BTw, the Z engines like to run warm anyway. I never run mine when it is cool, I always make sure it is warmed up at the track, and usually my second pass after the car has sat will be my faster pass. My dyno results also confirmed this, as did Clark at JWT. I set my electric to come one after the thermostat opens. In fact, I blew the fuse in it the other day when I went up to the drag strip, and I had no cooling issues, even with no fan. I was not just sitting in traffic idling though. As for intercoolers, I don't like a stock one for anything anymore. I think they are designed to keep a stock engine at stock boost cooled ok, but they are just not designed to do what most people need. The NPR is not a good unit either. I have an HKS one, and I plan on replacing it either late this year or early next year. I think your conquest one can handle what you are planning on doing. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted June 1, 2002 Author Share Posted June 1, 2002 Installed the fan on the passenger's side and it fixed all cooling issues. I think it's helping a lot to have the oil cooler out in front of it. The temp gauge is now happily on the left side of center while city driving, and for some reason it goes up while on the freeway almost to the center. I think it has to do with the fact that I don't have over drive. I think an alternator upgrade will be added to my parts I should have list. That oil cooler gets pretty hot, I think it's a good size for my application, but maybe bigger would be better. Thanks for your input. I have to re-adjust the AFM again, it's way off since I moved it away from the turbo. Seems like I'm going to have to run super rich when out of boost to compensate. Hopefully the IC will correct this a little. This AFM is really pissing me off, might be because my spring is tired of being tighter than stock. If someone can figure out and let me know what I have to do to modify my 280ZXT harness to use the 300ZX Turbo ECU and mass air please pass the info over. I think it may fix my fuel map a bit. I know it's hard to get the setup to work well with larger injectors, but as someone suggested using un-meetered air could solve the prob. If someone has an engine wiring harness diagram for the Z31 Turbo that would help me a bunch. I picked up a haynes manual, but it doesn't have the EFI harness diagram! PS, that picture makes it look like my car has cancer right there, when actually it's just really dirty. The car is actually pretty rust free. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 1, 2002 Share Posted June 1, 2002 Tony, the base timing should be set at 24 degree's, plus or minus 4 according to the sticker under my hood. I usually set mine around 20. There is a thread out there on the 300 ZX ecu swap, not sure if under here or the EFI section. That would help. What size injector are you running? I would think stock turbo injectors would be more than adequate for you application. You could also try manipulating your fuel pressure as a way to control richness. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 7, 2002 Share Posted June 7, 2002 why is the NPR intercooler not considered to be a good one? They are very large and have very large inlet/outlet pipes. Just curious. -jeremy- Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 7, 2002 Share Posted June 7, 2002 Bigger is good for cooling the air but bigger is also bad because it'll loose more boost. So inless you have lot of boost, the large intercooler will only drops your boost Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted June 7, 2002 Share Posted June 7, 2002 Just because an IC has more volume (what I think of when I hear "bigger") it will not "lose boost". The aspect of an intercooler that creates a loss of boost (or more correctly, a pressure drop) is the 'charge area' or typically the area covered by the end tanks. This isn't the be-all/end-all, the type of construction and the width of the IC also have roles in pressure drop. The reason the NPRs are not the ultimate IC is because they are somewhat thin - unless you use the tallest unit, you will drop significant pressure across it. The only issues people generally have with larger intercoolers is a bit more spool-up (the larger volume takes a bit more time to pressurize), and less fresh air to the radiator, possibly creating cooling problems. Quote Link to comment Share on other sites More sharing options...
utvolman99 Posted June 7, 2002 Share Posted June 7, 2002 Here is a guy who solved some cooling problems in a different way. You may want to check this out. I think I will do this with my V8 Z. This site is listed on Pete's links page. cooling Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted June 7, 2002 Share Posted June 7, 2002 SleeperZ, thanks for clarifying things. I wonder how many people criticizing a part is doing so based on their experience with those parts or just theorizing. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted June 7, 2002 Share Posted June 7, 2002 Couple of suggestions: 1) get rid of the electric fan and go to a mechanical with a shroud. 2) Install a hood from a 77-78 Z that has the hood vents. 3) Add an "undercarriage splash pan". I know everyone likes the electric fans and sometimes they are your only option, but I have to agree with JTR on this one. Electric motors simply do not have the horsepower and cannot move as much air. I have the hood vents on my 70. They release an impressive amount of heat when stopped on a hot day. The cooling link posted above suggests idling the car with the hood released. Looks like a good way to determine if a vented hood will help. The undercarriage splash pans are available from MSA. Apparently there is a lot of turbulence under the car. This pan helps smooth out the flow of air through the radiator at speed. Obviously if you are overheating at idle, the pan won't help. My 2 cents. Quote Link to comment Share on other sites More sharing options...
DAW Posted June 7, 2002 Share Posted June 7, 2002 Since your temps are going up at freeway driving more than around town, I'd bet on a scaled up core in the radiator, restricting coolant flow, or the splash pan factor. BTW the LD28 incorporates a water/oil cooler which runs the heater hose through the oil filter base housing. It's a bolt-on, and you could still run your aftermarket oil cooler base sandwiched under the filter. Measure the actual temp that the thermostat is opening and initiating the cross flow of coolant across the top tank of the radiator (180 is good), and remember that ethylene glycol has a higher specific heat than plain water so run at least 50/50 mix. DAW Quote Link to comment Share on other sites More sharing options...
DAW Posted June 7, 2002 Share Posted June 7, 2002 Tony, BTW I found a V8 Mercedes radiator (aluminum) that fits well in place of the Z radiator and is a bit longer but narrower, enough to be shifted to the right side so that I run the air filter to AFM hose through that space and lets my intercooler hose run out the hole in the radiator support, normally used for the AFM intake hose. DAW Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 7, 2002 Share Posted June 7, 2002 Hey DAW, can you put up a picture of that radiator installed? Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 7, 2002 Share Posted June 7, 2002 BTW, I hate those clutch fans, and my electric does a nice job of keeping mine cool, at least as cool as it will run when it is hot as heck out. Of course having a big old intercooler out in front over everything doesn't help. One of the things I have noticed is the stock turbo cars had an additional electric fan on the condendsor side of the car, on the passenger side. I assume that came on when the ac came on, but I have never been able to figure that one out. Of course mine is long gone. I think I am just going to break down and get a big old aluminum job and be done with it. Nothing to worry about there. Quote Link to comment Share on other sites More sharing options...
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