turbeau Posted August 26, 2009 Share Posted August 26, 2009 my car revs up to about 5500 rpm then the power drops off, im losing all my drag races on the top end. Will a performance cam give me more revs and some real HP up top? I run about a 10.5 in the 1/8 mile, seems slow. I dont know anything about cams yet, like what else i have to replace if i put one in (lash pads, springs, rocker arms)? I was thinking stage 1? Setup is l28, SU'ed, headers, exhaust, lightened flywheel. thanks for any advice Quote Link to comment Share on other sites More sharing options...
jc052685 Posted August 26, 2009 Share Posted August 26, 2009 Put a wideband on there first and see what kinda tune your SUs are in. Timming is a big factor too. What is it set at? Quote Link to comment Share on other sites More sharing options...
Xnke Posted August 26, 2009 Share Posted August 26, 2009 Use a wideband O2 to see if you are ok on mixture, then get springs, retainers, lash pads, and reground rockers to go with that new reground cam. Use a Nissan cam core, and look for something with a 280-290* total duration, or something with 230-240* duration at 0.050" lift. Delta cams, Web Cams, American Cam, just about all of them except Schneider came recommended when I asked. Schneider cams have a bad rep for going flat, but the springs and retainers are ok. Usually, cams in this range push the power band up to around 6600, but keep in mind, stock SU's can start to run out of air at about 5500 too. It all depends on exactly how you are setup to run. Quote Link to comment Share on other sites More sharing options...
johnc Posted August 26, 2009 Share Posted August 26, 2009 Try a tune up including valve adjust. Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 26, 2009 Share Posted August 26, 2009 my car revs up to about 5500 rpm then the power drops off, im losing all my drag races on the top end. Will a performance cam give me more revs and some real HP up top? I run about a 10.5 in the 1/8 mile, seems slow. I dont know anything about cams yet, like what else i have to replace if i put one in (lash pads, springs, rocker arms)? I was thinking stage 1? Setup is l28, SU'ed, headers, exhaust, lightened flywheel. thanks for any advice Cam, compression, and gear ratio should all match. If you want a fast drag car with good top end then use 10:1 cr, a cam in the 290 degree range, proper springs and lash pads, and a 3.90 to 4.11 gear. To get 10:1 cr use flat top pistons and a N42 or N47 head. If you have a 8.3:1 cr L28 (1975 to 1980 engine) then it will not take much cam. A stage 1 MSA cam would be about the max you should use. It will help but not that much by itself. A change to 3.90 will help if you are using a 3.55. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 26, 2009 Share Posted August 26, 2009 A huge cam (on it's own) would probably just slow you down. Like Pyro said you also need to do a lot of things like increase compression, get the RPM's up with gearing, and get a WB02 so you know that the carburetors are able to keep up with it. Since this is a hybrid site, my first thought for a successful drag car was that you needed to buy a V8 cam and then get the rest of the V8 to wrap around it Quote Link to comment Share on other sites More sharing options...
MAG58 Posted August 26, 2009 Share Posted August 26, 2009 Man makes sense. I usually don't like the American V8, but it's very hard to ignore the results. Americans have been going fast in a straight line for years, and they've become good at it. I know if I was making a drag car that's the route I'd be taking. Any more, it would be equally as easy to toss a SBC with a worked over auto as it would be to toss in a high strung L6. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 27, 2009 Share Posted August 27, 2009 Man makes sense. I usually don't like the American V8, but it's very hard to ignore the results. Americans have been going fast in a straight line for years, and they've become good at it. I know if I was making a drag car that's the route I'd be taking. Any more, it would be equally as easy to toss a SBC with a worked over auto as it would be to toss in a high strung L6. Nah, the best option would be a high strung V8. Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 27, 2009 Share Posted August 27, 2009 adding a turbo is an easy way to make power. Quote Link to comment Share on other sites More sharing options...
cockerstar Posted August 27, 2009 Share Posted August 27, 2009 adding a turbo is an easy way to make power. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted August 27, 2009 Share Posted August 27, 2009 adding a turbo is an easy way to make power. So is adding two cylinders Quote Link to comment Share on other sites More sharing options...
turbeau Posted August 27, 2009 Author Share Posted August 27, 2009 hybridz is the best forum because of people like you guys. this is only a part time drag car (just for fun drag car) so no SBC for me. I will continue my research and hopefully unlock a little more power. Quote Link to comment Share on other sites More sharing options...
Pyro Posted August 27, 2009 Share Posted August 27, 2009 hybridz is the best forum because of people like you guys. this is only a part time drag car (just for fun drag car) so no SBC for me. I will continue my research and hopefully unlock a little more power. The cheapest way to add a little power is with more cam, more gears, and more compression. What is your current setup? flat tops (81 to 83 engine) or dished pistons (75 to 80)? what cylinder head do you have? And easy way to go up in cam size is to send your old cam for a regrind and get the rockers resurfaced. If you stay at 260 degrees (212 at 0.050") and around 0.430" lift then you can use the stock springs and retainers and use stock compression and gears. A regrind this size typically requires 0.160" thick lash pads to correct the valve train geometry. DeltaCam does cam regrinds for 60.00 and rockerarm resurface for 4.00/each. Courtesy nissan sells thicker lash pads for 3.00/each. So for 144.00 plus 20.00 in shipping you can add maybe 15 to 20hp. Quote Link to comment Share on other sites More sharing options...
turbeau Posted August 29, 2009 Author Share Posted August 29, 2009 Pyro, that is exactly what I had in mind. I have a F54 block and N47 head. I think the motor is from an 80'. That means dished but how can I tell for sure? Also, can use the serial number on the block to check the year? Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted August 29, 2009 Share Posted August 29, 2009 If it was an F54 black and came out of a N/A car it's a flat top unless it was rebuilt with different pistons. The Turbo F54s had 10cc dished pistons. What did this motor come out of? Quote Link to comment Share on other sites More sharing options...
JessZ Posted August 29, 2009 Share Posted August 29, 2009 When I was running SU's on my L24 I advanced the timing as much as I could, then backed off on the idle via carbs. This did give my some more push at the top end. Quote Link to comment Share on other sites More sharing options...
Daeron Posted August 30, 2009 Share Posted August 30, 2009 Cam, compression, and gear ratio should all match. If you want a fast drag car with good top end then use 10:1 cr, a cam in the 290 degree range, proper springs and lash pads, and a 3.90 to 4.11 gear. To get 10:1 cr use flat top pistons and a N42 or N47 head. If you have a 8.3:1 cr L28 (1975 to 1980 engine) then it will not take much cam. A stage 1 MSA cam would be about the max you should use. It will help but not that much by itself. A change to 3.90 will help if you are using a 3.55. A great post; the only thing to add to it is that the very first statement is the truest part. The rest is EXTREMELY ABBREVIATED, but you could write books and books covering the second two paragraphs of this post. The first sentence, though, is the simplest answer to the OP's question, and any other answer you listen to should be listened to with THAT grain of salt. Quote Link to comment Share on other sites More sharing options...
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