Guest dawg95_2000 Posted February 10, 2004 Share Posted February 10, 2004 How much horsepower and/or torque would I get if i perform the following things to L28: Flattops w/ N47 head and felpro gasket- 10.1 compression? 2.5 exhaust, no cat, dynomax super turbo Half-arse match port job and maybe port the intake and exhaust manifold as best I can. If anyone can give me some estimates- optimistic or not, it would be appreciated. Quote Link to comment Share on other sites More sharing options...
Guest zcarjunky Posted February 10, 2004 Share Posted February 10, 2004 not a whole lot more than stock. Noticeable, but the numbers aren't that much higher. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 10, 2004 Share Posted February 10, 2004 I had nearly the same motor, built up in stages (eventually it ended up being a 2.9L, with a mild cam, rebuilt SU's, headers... you name it) when I was at about the stage you're talking about I was putting down about 150hp at the wheels. Quote Link to comment Share on other sites More sharing options...
Guest dawg95_2000 Posted February 10, 2004 Share Posted February 10, 2004 But what's "not a whole lot more than stock"- 10-20 hp? Because I would be quite content w/ that. Quote Link to comment Share on other sites More sharing options...
Mack Posted February 10, 2004 Share Posted February 10, 2004 well, stockers put down about 125rwhp in gooood shape, most are putting down in the high 1 teens. as in about 118rwhp. so, if bastaad525 was laying down 150rwhp, thats about a 30rwhp jump in stock, which would be damn good! that'd be about what, 40 flywheel hp? I plan on doing prettymuch the same thing. except I am using a maxima N47 which should be good for about 10.5:1 and has nicer chambers. that and I am also installing a 260Z "C" stamp cam. 256 degrees duration on both sides. which would be a nice 16 degree jump over a stock late model P79 cam. I'll be happy with about 160rwhp. McAdam Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted February 10, 2004 Share Posted February 10, 2004 I think a good starting point is double that. Does the 260 cam have oil holes in it? I am thinking not but cannot really remember, so you may need to come up with the cam towers off an early model head, and the spray bar, or you won't have 16 degrees more duration for long. Quote Link to comment Share on other sites More sharing options...
Mack Posted February 10, 2004 Share Posted February 10, 2004 lol! yes, the cam woulndt have that much duration for long! But, yes the 260Z had an oil spray bar. I snagged that along with the cam towers off of the E88 head. I also pulled all rocker arms and kept them in order, along with lash pads. I got the complete set-up for $25, lol!! its going in the car in about a week or so. McAdam Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 11, 2004 Share Posted February 11, 2004 found my old dyno sheet, actually my rwhp at the time, which was a 10.3:1 compression motor, flat top pistons with an N42 head, stock cam, stock EFI with an adjustable fuel pressure regulator to increase fuel for the higher compression, 3-2-1 headers into free flow cat and muffler, 60mm throttle body, made 141rwhp at 5200rpm, and 160 ft lbs at 4400rpm. Quote Link to comment Share on other sites More sharing options...
Mack Posted February 11, 2004 Share Posted February 11, 2004 how many miles were on the bottom end? i think the cam was the limiting factor there. Also, my head has minor valve bowl work where I cleaned up a few of the shapr ridges in there. It should be fun. hopefully I'll have it done in time for the local 240sx clubs dyno day. McAdam Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 11, 2004 Share Posted February 11, 2004 The entire motor was rebuilt. I also had the bowls smoothed out a little, and some minor (very minor) smoothing of the ports as well. This was also with .060" over sized pistons, which technically made the motor a 2.9L. The only things I changed to bring it up from 141 to 160hp was switching over to SU carbs and putting in the mild cam (480 lift 270 duration cam), and of course not running a catalyst anymore, these changes were made when I pulled that motor from my '81 ZX and put it into a '72 240. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted February 11, 2004 Share Posted February 11, 2004 found my old dyno sheet, actually my rwhp at the time, which was a 10.3:1 compression motor, flat top pistons with an N42 head, stock cam, stock EFI with an adjustable fuel pressure regulator to increase fuel for the higher compression, 3-2-1 headers into free flow cat and muffler, 60mm throttle body, made 141rwhp at 5200rpm, and 160 ft lbs at 4400rpm. Mine made that much HP before the boost hit. HAHA Sorry I could not help it. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 11, 2004 Share Posted February 11, 2004 s'okay I'm right there with ya ... yeah the 40 extra horses and 65ft lbs of torque are nice... too bad they only cost me like FIVE GRAND! Quote Link to comment Share on other sites More sharing options...
kalium99 Posted February 12, 2004 Share Posted February 12, 2004 The entire motor was rebuilt. I also had the bowls smoothed out a little' date=' and some minor (very minor) smoothing of the ports as well. This was also with .060" over sized pistons, which technically made the motor a 2.9L. The only things I changed to bring it up from 141 to 160hp was switching over to SU carbs and putting in the mild cam (480 lift 270 duration cam), and of course not running a catalyst anymore, these changes were made when I pulled that motor from my '81 ZX and put it into a '72 240.[/quote'] Thats sounds like almost the same setup I am doing with my L28. Did you regret going to the carbs? (even though u got more HP) Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 12, 2004 Share Posted February 12, 2004 The SU's had both benefits and drawbacks compared to the EFI. I dont feel the carbs had much to do with the increased HP, rather, I think the extra HP was a result of switching to a hotter cam, which moved the torque range up, resulting in higher peak hp. I really couldn't say for sure if the carbs helped or not, or maybe even hurt performance? Problem is, the EFI in my ZX was never working exactly 'right' either, it had it's bugs, but did put down good power considering the only mod to allow me to really tune it was the adj. FPR, and was running such high compression. Problem is stock EFI really isn't flexible enough on these old cars to really be able to compensate for extreme mods like that. I wouldn't say I regretted switchign over, if only because I was always chasing bugs with the EFI, and the SU's were rebuilt, and so easy to tune and figure out... no wires... no sensors. But the SU's weren't perfect either, gas mileage sucked on the street, and I dont feel the needles that Ztherapy provided with them (SM needles, very popular for this application) were really the 'right' needles... custom needles would have probably helped a LOT. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted February 12, 2004 Share Posted February 12, 2004 s'okay I'm right there with ya ... yeah the 40 extra horses and 65ft lbs of torque are nice... too bad they only cost me like FIVE GRAND! Yeah well hows it go? Speed costs money, how much you wanna spend? I always liked the other benefits of the turbo engine. It sounds tame, so people don't expect your car to be fast, you don't break rings revving the snot out of it, you don't have to adjust the valves as frequently, and of course once you are set up, more horsepower is only some good gas and an extra 5 psi away. Not to mention getting sideways in second gear when the boost hits, now thats what I call fun. Quote Link to comment Share on other sites More sharing options...
zero Posted February 14, 2004 Share Posted February 14, 2004 while this conversation is going on, i may as well ask how much power you guys think my car is putting out. I have: l24 block bored .4over 72 head, ported, and 3 angle valve job Flattops that are flush with top of the bore Schooler cam no 483 timing at the 3rd mark, or about 8degrees advanced straight through exhaust roundtop su's k&n's EDIT: I also have a 6-2-1 header that i seem to have forgotten about. Thanks Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 14, 2004 Share Posted February 14, 2004 170-200hp at the wheels, that's my guesstimate. Quote Link to comment Share on other sites More sharing options...
zero Posted February 14, 2004 Share Posted February 14, 2004 very very nice. Now how quick 0-60 and 1/4 do you think i would be with a 5speed in a 240. I have yet to get it running to test it so im getting excited. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 15, 2004 Share Posted February 15, 2004 0-60 in about 6 seconds, mid 14 second 1/4 mile. Quote Link to comment Share on other sites More sharing options...
zero Posted February 15, 2004 Share Posted February 15, 2004 thanks man, You made my week. Quote Link to comment Share on other sites More sharing options...
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