Gollum

The main drawback to most of the fun roads that are truly "in the bay area" is that they're generally crowded with cyclists and foot runners. Be very careful out there. That's one of the nicer things about having moved out to Vacaville for me, is that for the first time in my life there's SEVERAL local roads that are awesome drives that I rarely see traffic on. Not that I endorse crossing the lines, or speeding, but things happen on windy roads and the less traffic the safer they seem to be. Road conditions are also better out here too. Roads in the bay area are fairly abysmal. Regarding meets, I throw one at least once a year, usually mid/late summer. Pretty good size shindigs with burgers, plenty of diversity, and all around good people. One thing you'll probably notice is that many of the south bay car guys (z car guys are better, but not immune) tend to be pretty exclusive to their area. While guys from the Sac, modesto, marin, and even modesto regularly drive several hours to get to a car meet, south bay guys like to stay within a 30 minute drive. Part of it I'm sure is the fact that traffic is so bad out there that many have little desire to go further than needed, but it's gotten past being humorous for me. A good example is that I've sold a lot of stuff on craigslist, and the only times I've had people ask for me to drive to them, or meet them half way is when they're from the south bay. It hasn't just happened a couple of times, but a lot. One time a guy wanted to buy a $20 oil pump from me, and wanted me to travel an hour to meet him.... yea right...

You know, one of these days I'm going to do some documented, scientific testing to put some myths to bed. And here's what I'd like to do. 1. Prep two as identical as possible F54 shortblocks, one with flat tops and one with dish pistons. 2. Prep a P90 to as OEM specs as possible. 3. Dyno the head on each shortblock with race gas to find ideal timing requirements. 3. Dyno with pump gas to find true detonation limitations. I have yet to see a SINGLE blown turbo motor using the NA flat top short block that actually failed due to the higher compression. Usually these failures are from people trying to just slap a P90 and turbo or just a turbo on the NA engine without resolving the engine management issues, and it it DOES knock it's because they're running the NA ECU which won't retard timing under boost. I even have a stock '81 280ZX waiting for an engine rebuild, and I have a spare P90 sitting on my shelf... Maybe one of these days I'll get around to it. I still firmly believe that all the hype about "not being able to run as much timing" is widely misunderstood. More timing isn't always better. Ideal timing is ALWAYS better. Know where the power for YOUR setup is, and strive to get there. KNOW the fuel you use, and what it's burn characteristics is. It's well documented that there's more power in timing than in compression, but many people fail to understand that not all setups will make peak power at the same timing specs. I don't know how many ways I can say this, but a smaller chamber space doesn't need as much time to burn completely, thus requires less timing for ideal power. Just because you raise compression with flat tops and can't run as much timing doesn't MEAN you've LOST POWER!!! I'm not saying run as much compression as you want. I'm just saying I don't think we have enough concrete information (from what I've seen) to make blanket statements about what's "best".

You know, the irony I find in that Z is that every top I've seen on a cobra just looks wrong, or like and afterthought. When's first saw that z though I thought it actually worked, and seeing it again I think I believe so even more. It's one good looking car.

I think, and this is just thinking and really grasping at straws here, if you order the RB, and NOT the RB-R rim the center cap MIGHT clear. Reason being is that the original RB prototype used basically a cast in place spacer to get to the offset specifications that we were wanting. When the prototype came in Chris was like "what the hell, this isn't the RB?!" and after contacting rota found out it was the RB-R that we wanted, and then he also specified that we'd like it if the rim spokes were actually moved in, not just mass added to the mounting surface. As far as I know, BOTH went into production. The RB rim is heavier and has less lip, and thus also has deeper sunken lug holes hence the center cap mount surface is further from the actual hub. If only the RB-R went into production then center caps will not really have a hope to fit. Custom caps would be required. Personally, I'd say just get your caps painted and call it good.

Anyone else hear that knocking? I think it's opportunity. Sounds like it's saying, "Mike, buy a turbo for that bimmer." You know, there's not many bimmers I really would like to own, and the E36M3 is one of them.

10k for a 400hp L28ET eh?.... Mighty spendy for such a simple power solution. Has anyone here with 400+whp with their turbo L spent more than 10k? And if you have, are all those parts actually on the car? I know some have gone through 2, 3 or 4 turbo setups, multiple intakes, etc. That starts to get expensive. I hope this doesn't sound to arrogant, but I bet I could make a fairly reliably 400hp L28ET for under 5k. Only reason I haven't is that I have less than 2k in my ENTIRE CAR.

Let it be shown for the record I don't disagree with this at all. I said "probably" because the scenario I was describing is usually when people put race gas in which isn't anything like pump gas and they do it for tuning reasons, then they see how much extra timing they can run and how much power it produces and assume it's "just timing", which isn't necessarily the case. Timing is VERY important, but it's not always a linear comparison from setup to setup. That's what gets people screwed up when comparing setups. Even in the datsun case, comparing a P90 with dish pistons and a P90 to flat tops is NOT apples to apples for timing requirements. It's a completely different combustion shape and flame front speed, thus different optimum timing requirements. For example, if you took detonation out of the picture, and could run "optimum" timing at all RPM, you'd see that a flat top+P90 combo started falling off power SOONER, than dish+P90, regardless of which one is making more or less. This example should hopefully show how one engine might "require" more or less timing versus another. If guy A is runing 32 total timing, and guy B is making more power with 35 total timing, that doesn't mean guy A will make more power by adding in 3 degrees of total timing.

You my friend, seem to have a good head on your shoulders. And just so you know, your goals are entirely realistic. Focus on good chamber work and you'll be fine, despite the terrible intake. Past 300hp I'd seriously consider a better intake of course, but we're all limited by certain things, like money, and as such few actually take the time to make or buy a quality intake for their L motor.

My suggestion would be to look into sunbelt cams, and other people that have made L specific cams. This might not mean much on turbo application, but several people's research indicates that the majority of common aftermarket cams out there were designed around other brand engines and their valve train, namely BMW. Sunbelt is among the few that actually designed aftermarket cams around the L motor's drivetrain geometry and ended up being able to make larger lift and duration cams that could use factory seat pressure just fine with no float issues. Most cam retailers offer L cams will tell you to upgrade springs for anything other than a mild upgrade, while people were making substantially improved power with minimal seat pressure on cams actually designed for the motor. The old timers in this field is isky, and are highly recommended by many. Many a builders have used their cams with GREAT sucess. 715149 is their part number for their stage 3 cam, which is basically a high lift cam with slightly more duration than a stock cam. I believe isky will also do custom grinds if you want more lift with less overlap, specifically for turbo application. Also, just their stage 1 cam would be more than youre .460 lift you were looking for, at .475, with 222 degrees of duration. I'm not sure what the lobe centers are. That 222 degrees is the same duration (or nearly so) as a stock turbo cam would have, and roughly 10 degrees less than the 240Z A cam mentioned. This should show that running a little more duration isn't exactly a bad thing on a turbo application, seeing as the "A" cam does so well. I'd go with the stage 2 or 3 isky cam if you go with isky. 300whp is easy btw. Add air with extra boost or better flowing head, and make sure you have an ECU that can tune it. The stock turbo will be way out of efficiency at that power level, but a well sized T3/T4 hybrid would do the trick. Some people have used Holset turbos with success too. 300hp is old hat, and easy to do. People have done it a million different ways. There's no "magic setup". I can say "well this is what you need to do" then I can show you a build that contradicts me. People have done it with bone stock longblocks, stock turbos, and stock injectors, and even with stock ECUs. I can't think of any that used ALL of those stock parts, but some have come close. One guy using stock injectors had his rail pressures over 100psi and used a twin pump setup. Some people using stock turbos use meth/water injection to combat the heat. Some using the stock ECU use RRFPRs with a larger turbo closer to it's peak efficiency in that application to get there. For most purposes, 400whp is the point at which things become sketchy. At that point the stock pistons will blow head gaskets and ringlands with mild detonation, that's usually very hard to catch before it's too late. What I've heard people say, which I think is great advice, is to tune your ECU on junkyard bottom ends. If you blow it up, go get another. No big deal. Then when you've got your tune solid and you're pushing your power goals on stock pistons, then build up your forged piston bottom end. You can easily blow up your forged pistons due to a bad tune at 400hp. Get the tune straight FIRST, then you won't be wasting money. No a requirement, just advice from people who've been there.

Another good thread to look at http://forums.hybrid...p-progress-pics Flatblack is another member that just came to mind. He was running a NA-T conversion and I'm sure he was probably knocking on the door of 300hp. He's someone who's still around often that can be PM'ed.

I'll do some digging for some people running turbo+flat top setups, but I also expect you to search as well. That said, I find it funny going through old threads like this one - http://forums.hybridz.org/index.php/topic/13564-i-need-help-on-my-280zx-turbo-project Notice that though people are suggesting starting with a turbo motor, nobody is freaking out about the compression, or saying that the NA motor can't be turbo'ed. It's just me guess, but I'm betting people like scottie were suggesting starting with the turbo for a COMBINATION of reason, and a big part of that is that the oil pan is already tapped for oil return, there's already an oil fitting to go to the turbo at the pressure sensor. There's already larger injectors. It already has a turbo exhaust manifold. The list goes on. Yet, nobody (at that time, in 2002) seemed to care to bring up the compression aspect.... Food for thought? There's two people here who did NA->turbo conversions. Cody is still fairly active, send him a PM and find out how much boost he braved before he wreaked that first Z of his http://forums.hybridz.org/index.php/topic/20021-has-anyone-put-a-turbo-on-a-na-block More people you can PM http://forums.hybridz.org/index.php/topic/23501-calling-all-flat-top-piston-turbo-z-owners/ You can see a similar discussion that comes up quite often in the NA realm too. User: Mack has run MUCH higher compression on pump gas than others recommend, or even think possible (again, some people). Some people say running anything above 9.5:1 NA is just too much for pump gas, yet there's people running 10.5, even 11:1 on street driven Z cars. There's WAY more that's going on than just static compression that results in detonation issues. Some people are convinced that more timing with lower comrpession is the "only" way to get better street power. I'd say that's true, but it's not THE truth. I'd say a higher level of truth is that each gas type has it's own compression and timing curve abilities and requirements. If you run a lower compression NA motor, you're in some ways wasting money by running high octane gas just to run a few more points of timing. Some people will also say "well I put race gas in and bumped the timing and got 15 extra HP!"... Well yea, but what power did you gain at the same as stock timing versus lower octane gas? The higher octane gas probably has more energy potential, so really you're just utilizing it better by matching your timing TO THAT FUEL. You might know all this already, I just want to make sure it's clear why I've said that FLAT TOPS are FINE on a turbo motor. If you want to run an OEM EFI setup, just get a L28ET longblock and be done with it. If you want to do a low buck turbo L motor use whatever you got, and run a good programmable EFI in order to tailor the fuel and timing to THAT SETUP. I've seen lots of blown up turbo L motors, and more often than not it's from a bad tune. It doesn't matter if it's flat top 7.4:1 or a 8.5:1. Run the TIMING REQUIRED for THAT fuel at THAT compression ratio and you won't have detonation issues. And in fact, running flat tops on the P79/90 will give you a ton more QUENCH thus you might be able to run similar timing maps anyways. But also remember that with a smaller combustion chamber with flat tops the distance for the flame front to travel is smaller, thus less timing is needed to optimize timing. Where people get messed up is they say "well I can run more timing on my dish setup, so it must be better". That's a very closed minded way to look at it. On a larger chamber more timing is REQUIRED, not allowed. It's just perspective, but it changes everything. Want a real mind bender? There's people running alcohol classes at the drag strip running non-intercooled roots superchargers on motors with 13:1 compression and higher! I bet they're not running extremely advanced timing, but I bet there's nobody out there telling them "you're loosing power by running such high compression"......

Well you've come to the right place. Check out the L-specific threads in the FAQ section of the forum. People have done builds all from 300-700hp on L blocks on this very forum. Most are pretty well documented as well. Check out BRAAP's threads in which he goes through head work stuff, you can pick up on some of the key points to focus your headwork. And as far as the "been there done that", my advice stands. Find the "A" nissan cam. It's a great cam for turbo application and has shown to put down better numbers than some aftermarket "turbo" cams. Also, what's your goals with this build? 300whp? 350, 400, 450, 500? You'll find hundreds of builds like mine running mostly OEM longblocks, because it does fine getting you to 300hp, at which point the car becomes a handfiul.

Possibly. Or maybe it was a dream I had in which you were cracking the displacement myth whips.

Haha, it's kinda funny. I thought this was a new thread at first because the high-displacement extra stroke L motors came up recently in a thread here. I thought this was Tony's response, but instead it looks like tony's response to the same issue.... THREE YEARS ago... And some noobs wonder why people get mad...

It's been fairly well covered here, but I'll add my 2 cents to the pile. The Compression of the flat top + P79 issue is WAY overblown. Both a dish+P90 and flat top+P79 have shown to be capable of well beyond 300whp under boost on pump gas. The liner topic is almost mythical. Though people on this very forum HAVE had issues with P79 liners melting up on them, they've been very isolated incidents while others (like howlermonkey) point out that it isn't always an issue. If you want to grind them out, feel free to do so. Shouldn't really help or hurt flow much in a turbo application (or NA really either) The key to getting ANY motor to run nice ARs without detonation is good management. The L motor is no different. I've seen SEVERAL people blow up flat top+P79 combos because they tried to use the stock L28E management, or tried to use stock L28E injectors, or tried to use stock L28E AFMs. It simply won't work well. If you want to try to use the L28ET EFI, then do it right and get every piece, including dizzy from 82-83. That being said, just go MS and be done with it. Install a trigger wheel and add some coil packs for MS to trigger. People have shown timing logs from MS and even the L28ET dizzy has very sporadic spark when compared to what you'll get from a good trigger wheel. And of course, I can't leave this post alone without advertising the best magic bullet to hit the car scene in the last 30 years (in my very honest but humble opinion). If you're willing to buy all new fuel lines, fuel injectors, and a large aftermarket pump, just go E85. That will eliminate ALL fear of detonation due to a "scary" 8.5:1 (a ridiculous fear in my opinion) and the cooler combustion temps will probably also help prevent any possible liner failure. It just means much larger injectors are required and you need rubber and lines that won't deteriorate. Small budget increase when you're already looking at MS3 + turbo, etc. As far as turbo fitment, I've see T4's fit with flange adapters. The stock turbo location is a little high and can stand to be lowered a little. Depending on what turbo you're wanting to run, and what kind of money you're looking at spending, you might just be better off getting a new manifold made. Not everyone's cup of tea, especially considering people make it past 300whp on the stock manifolds + turbos that bolt on without modification.

Goals??? If you want 300hp there's several (some even on this board) that can build a head that will flow plenty well, and possibly every bit as well as that kameari head. I'm not saying kameari is not any good, I'm just saying there's LOTS of people still around that do work on L6 heads that know the tricks to getting great power out of them. And you'll probably spend less than half that...

Which means pics for us tomorrow right?

The question is, is mike going to go bigger next time, or more "getting old" like ZR8ED seems to be headed... (all in good fun if you're reading this ZR8ED). If you respond to this Mike, realize I don't care what the response is now. I'll be looking toward what you actually pick up and what the plans are when it comes. Go enjoy the bike ride, clear the head, and remember why life is worth living.

If it was outrunning a VG30ET at 9lbs then I don't doubt the power claim. (we know they were both Z31's, and I'm assuming they were around the same weight) My personal opinion, is that if you can get the car for a song and a dance, go for it. Getting the same 250 hp out of the L motor will be more time, energy, and possibly money all for an engine that's longer and taller. It does sound better, and that really matters to some, but not everyone. I know you don't really need us to tell you if it's a good idea or not. It seems to me you're really just looking for someone to say it's ok for you to start another project, and I don't think you'll get many people arguing with you around here. All that said, doing the NA swap should be MUCH easier than the turbo swap you've done before. I'd say do it.

Wonderful cars must run in the family.

Who's doing the head? They should be the one recommending what cam to use, as it should match the head flow. If you're doing the headwork yourself then I'm surprised you're even wanting to go with an aftermarket cam. If you're going for that cheap DIY angle I'd be getting a 240Z "a" cam. And 24lb injectors is TINY unless your goal without the meth is only around 250wheel hp. It's much easier to get quality large injectors to idle nice than it is to get tiny injectors to make big HP. I'd recommend 30lb MINIMUM. Ideally I'd say go closer to 40-50 lb and don't buy generic, and try to get some that come with flow data to show that they're closely matched. And remember, if the head is flowing well, 10psi might already have those 25lb injectors maxing out at stock rail pressure. Go through big phil's videos and find the video of him and another member on here dyno'ing their cars. Big phil had a stock head and was pushing like 25 psi and wasn't hitting 400whp. The other guy was running in the lower teens iirc and was making MORE power... But he also had a professionaly built head with a well matched cam and intake system. It makes a BIG difference.

What's the average weight and displacement of the MINI's you're used to? Reason I ask, is that I believe the Z will have much more displacement for the weight of the vehicle, meaning that it's going to feel much more "torquey". This is something I didn't really think about much until recently but I can go back through the history of all the cars I've driven and can definitely make the correlation in the numbers. A 1.8 liter CRX can actually "feel" like it's got more torque, or "power off idle", than a 4.7 liter toyota tundra. I can also say it this way. Torque is nearly meaningless without context. Torque more than anything is an indicator and should be used as such. A diesel isn't powerful off idle because it makes a crap ton of torque, it's actually because it makes so much bloody HP off idle. HP moves cars, not torque. HP puts you in your seat, not torque. But if I say an engine has 400lbs of torque off idle (we'll assume 1k rpm) that's over 75HP, which is a boatload when it's that low in RPM. It's going to get an object MOVING. The this is though, is that torque is directly tied to displacement in NA applications. So for comparing NA vehicles to NA vehicles, we can use displacement to weight to directly compare how they'll drive at low engine speeds, even if they behave very differently at peak HP. You're not driving at peak HP all the time, so for street driving I find the displacement/weight measurement very useful. So that's why I ask about the mini. The Z will weigh around 2200-2400 pounds, and 2.8 liter is more than 1 liter per 1,000 pounds, which is better than many muscle cars.

I think it'll work for your goals as long as the head is healthy and you induction system is well matched. I'd suggest playing with cam timing when it comes time to tune too.

This just about made my evening. ...then I remembered I still haven't ordered my MS-ll. Doh!!! (goes off to hide)

I agree that the EFI intake isn't an ideal mathc for running a long duration cam, though that doesn't mean it can't be done. So consider me seconding Pyro's view on that. Regarding the Z31, going that route and adding nistune is JUST AS EXPENSIVE AS GOING MEGASQUIRT! In fact i'd say it's even MORE expensive! If you want to do open source tuning and install your eprom yourself it can be done cheaper, but it's still going to be a lot of time and energy just to get a system that works almost as well as megasquirt. If you already have a Z31 ECU and harness available it's a worthwhile option to consider. If you want to run a stock-ish turbo setup it's a very pleasing option as just a plain ECU swap with the MAF sensor is a huge upgrade and will run a stock longblock L28ET very well. No tuning required really. But if you're looking to snag that 10-15% extra power sitting on the table, just go MS or something better even.