speeder Posted November 12, 2002 Share Posted November 12, 2002 Ian, My '77 in the sig is a good example of what happens when you have more money than sense. Quote Link to comment Share on other sites More sharing options...
Guest eric-z Posted November 14, 2002 Share Posted November 14, 2002 how about this.... L28 turbo block L24 crank L28 connecting rods L28 turbo pistons Quote Link to comment Share on other sites More sharing options...
speeder Posted November 14, 2002 Share Posted November 14, 2002 This one I can answer. You need to use the L24 rods with the L24 crank. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted November 14, 2002 Share Posted November 14, 2002 Why so fixated on the L24 crank? You can get pretty much whatever CR you want with an L28 crank (or with an LD28 crank even). Why give up all that displacement? Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted November 14, 2002 Share Posted November 14, 2002 Originally posted by Ian turbo240:I've gotta pipe in here. quote: oh yeah and the stock zx can take 25psi What stock 280ZXT engine are you talking about? The last time I ran 20psi on a stock 280ZXT engine, it blew a headgasket! Maybe what you meant is that the stock internals are capable of handling this amount of boost if you have the proper engine management and turbo using 100+ octane fuel. That's about the only way for any L engine to survive that amount of boost. Ian I'm not trying to start a war or anything, but I want to make a point clear here. Just because YOU blew a head gasket at 20psi doesn't imply all L28ETs will do the same thing. A small amount of detonation at 20 psi will certainly blow a gasket, but if your ignition timing is not out of whack, and you are fueling it and cooling it properly, factory gaskets will survive. That is a fact, I've seen it done repeatedly (on PUMP GAS - 91 octane), and I will be doing it myself this spring and summer. Admittedly, all my observation and experience is at 5000+' of elevation, where 25 psi boost is really like 23 psi at sea level. I don't think that invalidates my statements though. No offense meant, but I want to stress the point that it is detonation and lack of thermal management that breaks engines, not boost. Quote Link to comment Share on other sites More sharing options...
Guest Ian turbo240 Posted November 14, 2002 Share Posted November 14, 2002 I agree that with the proper fueling and intercooler, etc. the stock L28ET will handle 20+ psi boost. However, eric-z said stock. To me, stock means stock injectors, no intercooler, stock t3 turbo, stock exhaust, stock everything. When you start adding bigger injectors, intercooler, aftermarket EFI and the like, the engine is no longer stock. I blew a headgasket because the boost controller on my totally stock L28ET malfunctioned and the boost spiked to 20+psi. With no intercooler, and the stock f/i and injectors, the headgasket had no chance. My point was that there is no way the completely stock L28ET will take 20+ psi boost. Most people realize that anything over 10psi without an intercooler is risky, and 12psi with an intercooler is about the max on the stock injectors. Now that I think of it, I knew a guy who was running 38psi on a junkyard L28ET engine that was managed by the JWT setup. He had some huge injectors and intercooler. It was in a 280ZXT and ran low 11's in the quarter. There are plenty of people making big power on the stock L28ET block and head, but not with the stock fuel injection. Ian Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted November 14, 2002 Share Posted November 14, 2002 You are correct. I didn't understand the context of your statements. I agree you should not try to boost more than 12-14 psi on the stock fuel system or you will run into reliability issues, especially with the stock turbo. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted November 14, 2002 Share Posted November 14, 2002 I'll be installing L26/P79 combo and stock turbo, turbo EFI, and HKS IC on my car next month. I'll find out what it'll do. Quote Link to comment Share on other sites More sharing options...
Guest eric-z Posted November 14, 2002 Share Posted November 14, 2002 well I'm so stuck on the L24 crank because you can get less compression with it(at least to my knowledge). I don't know how low you can get the L28 but I bet you could lower it with the use of a L24 crank(I just think it is logical.. that is if you us the stock turbo pistons). check this out http://home.att.net/~jason510/Motorspecs.htm scroll down to the bottom of the page and you will find a section that says Low compression combination for use with turbocharger. now those are all 4cylinder engines. I'm just wondering about doing this with a 6(previous set up I posted) and probably a lower compression than what is on those engines. p.s. I got that site from grumpyvette. Thanks grumpy Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted November 14, 2002 Share Posted November 14, 2002 Dude, an L28 with dished pistons and a P90 head would have you at 7.4:1 CR. I can't imagine even the most boosted engine running less CR than that, but if you did want to you could use a 2mm head gasket and go down to 6.9:1. Or you could bore 2mm over and use Z22 pistons for CR in the 6.0 to 7.0 range (ridiculously low). CR is VERY sensitive to combustion chamber volume, you don't have to reduce stroke at all in order to get REALLY low compression ratios. If you're running enough boost to justify CR that low, I'm sure you'd be running forged pistons anyway, which you should be able to get with a much smaller dimension from wrist pin to the top of the piston than L28 pistons or with serious dish, and again could get a CR as low as you want. Your desire to use the L24 crank is bordering on fetishistic (izzat a word?). Even with a turbo, displacement is directly related to potential power output, so don't just throw it away for no reason. Quote Link to comment Share on other sites More sharing options...
Guest eric-z Posted November 14, 2002 Share Posted November 14, 2002 haha, alright, I give Quote Link to comment Share on other sites More sharing options...
Bob_H Posted November 15, 2002 Share Posted November 15, 2002 I'll just say i'm with dan. i love you man. Dan, you'll go nuts when you realize what i am really doing to my z, but I won't tell till Jan/Feb. There is a good chance I will write a series of articles in SportsZ about it. I did have a blast on the track with the stroker at Summit Point and Beaver Run. The Drift king. That little bugger was all over the place, esp. at summit. fun stuff. the RB26 should be here in a few weeks. goes to the cage shop next monday. i second what rick said, too much money for my own sense. eric. while you are on the right track with respect to compression ratio, your idea on how to get it will lose you more power than it is worth. the more stroke you keep, the more torque you will produce, which is directly related to how much you are pushed back in the seat. taken to an extreme, look at what jeffp has with his stroker. he is running in the 8's for CR. What I would suggest is around 8.0:1 CR with a high quality intercooler and good fuel management. you will be much much happier with that setup than a destroked 2.8L,(i.e. 2.4L crank), with some piston combo to run 7.0:1 compression. The engine will be a dog off boost,(that is related to the low CR), and will not produce as much power as an equally setup 2.8L motor. Enjoy. -Bob Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted November 15, 2002 Share Posted November 15, 2002 As an easy and cheap option that probably won't give you long life (but some grins) you could try a P90 head on a L24 block like I have. I'm using a hybrid turbo with t04b compressor, intercooled and a little modified 280zxt electronics. It really starts packing on the power over 5k rpms, and really pulls hard up to 6500rpm. I'm pretty sure it'll keep climing, but am afraid things might come apart up there. I haven't been in many turbo Z's, and I'm not sure what a L28ET is like winding up there, but my engine opens up real nice up there has this turbo'd Ferrari sound Quote Link to comment Share on other sites More sharing options...
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