Leon

Didactically speaking, the turbo will be doing something, just not much of it...

I think the logical thing to do is to replace the booster. How would a brake "upgrade" fix anything?

Well, if we're being pedantic... Tony, there are instants where there is compression of the air during Jake Brake operation and there are instants were the comressed air is being bled by an open exhaust valve. Compression ratio is defined as encapsulated volume in the cylinder at BDC divided by encapsulated volume at TDC. At TDC, the brake exhaust valve is open and the volume in the cylinder is essentially infinite. Therefore, at that point in time, the compression ratio is ZERO. I don't care what the turbos are doing, by your definition the intercooler becomes an aftercooler.

Time to replace the booster.

Tony, I understand what you mean by the engine acting as a subsequent stage of compression, but your explanation shows that you don't understand how the Jake Brake functions. The Jake Brake does not turn the engine into a pure compressor. What you're thinking of is a simple exhaust brake which slows the engine by increasing exhaust pressure (pumping losses). The Jake Brake operates on a completely different principle. It opens a separate "exhaust" valve during the compression stroke in order to bleed off cylinder pressure. If you draw up a p-V diagram of what's going on, the engine is making "negative horsepower" (roadwheels must drive the engine) thus slowing the truck down. Therefore, the mechanical function of the engine DOES change. My point being, while the Jake Brake is engaged, the engine is effectively running a 0:1 compression ratio. Will you concede now? I did originally stir this pot, but it was because I had learned this from a former Honeywell engineer, although he is into planes as well and some of his terminology may have come from the aero world. The Jake Brake info comes from a long-time Mack Trucks engineer.

Therefore, when an intercooled turbo-diesel truck is using a Jake Brake then the intercooler effectively becomes an aftercooler?

In the meantime, I've been planning the next major evolution of my 260Z. EDIS 6 with Megajolt! Webers stay (for now). Here is what my dog thinks of distributors:

I've been busy the last few weeks but the Z has had some attention. I finally installed my WB02 (14point7 Pure Plus), but it hasn't been working right. I have an exhaust leak at the gasket so that is definitely affecting the readings. Otherwise, the installation was painless. I'll post more on it once the issues are dealt with. On September 10th, I took the Z to my first autocross! The week before the event consisted of coming home after work and working on to-do items into the night. The day before the event, I was fiddling in the garage until 2am. Then woke up at 5am to go to the track... The event was a "test day" at Infineon, which consisted of punishing the car on a course set up in the paddock at Infineon Raceway for 4 hours or so. I drove the Z an hour there and back, and it survived. Goal 1 completed. Early start, on 101 North Almost there! Here we are, I drove up with a friend of mine in his Mazdaspeed3 As an aside before continuing, I've been dealing with vapor lock/fuel issues recently, so I taped a fuel pressure gauge to my windshield on the way to Infineon. You can see my "custom pressure gauge mount" in the next pic. Custom Pressure Gauge I'm running the stock mechanical and electrical fuel pumps. I found out that under moderate load, pressure drops until it hits zero. After driving on the freeway for a while, it tends to hesitate especially when climbing hills. I drove with the hood popped which may help a bit, but the issue persists even in cool weather, although heat does exacerbate the issue. I'm planning to install a Holley Red that I have and hopefully it cures the problem, along with the heat shield that I'll be making. The day was a ton of fun. About 30 cars showed up, with everything from a Cobra replica, to the typical Miatas, to a supercharged El Camino. In the morning, the course was split up into the "A" section and "B" section and we ran each configuration for over an hour. There were some really cool people at the event, with one guy letting me flog his Porsche Boxster around the course. I have to say, that car really surprised me. Outstanding handling, outstanding brakes and great torque, even for a "base" Boxster. Very impressive car. Adding to that, his friend let me take his Lotus Elise around the course a few times as well. Great guys and what a blast!!! At lunch we took some parade laps around the course, and it made me really itch to stretch the Z's legs on a full road course. That definitely needs to happen in the future. After lunch, the A & B sections were combined into a full course and we ran it for a few hours. The Z began to struggle when doing the full course (45-50sec). It was warm, but not really hot out, but after a run or two it would start to hesitate at the end of the run. If I stringed 3-4 runs together it would just stall at the end of the course and not start for 5-10 minutes. I did get a couple of nice, satisfying runs at the end but there is plenty for me to work on. Here is a video of a not-so-good run of mine. You can hear it start cutting out half-way and again towards the end of the course. Nearing the end of the event, I retired the Z and started bumming rides with those that were left. Got to ride along in some sweet cars, including an '80 Porsche 911, '00s Miata (awesome car), and a prepared beast of a Porsche 914. It was a long, very fun, memorable day! Goal 2 completed.

It's bedtime, but I'll put in a few words. Applications like F1 do sacrifice torque, it's not complete bollocks. In order to rev so high (~20,000 rpm), the stroke must be kept very short, thus the mechanical advantage on the crank is less. This equals less torque, but those engines spin so fast that the torque pulses to the crank are happening at a very high rate (more power). Really, when I see discussions like this there's always talk about torque does this, power does that, blah blah blah. Torque and power are related to each other by rpm. Whether you talk about torque or power, both of these things get a car moving. What we should really be talking about is BMEP - brake mean effective pressure. This is a true measure of the effectiveness of an engine no matter the displacement and allows for a valid comparison. It shows how much potential (cylinder pressure) is being extracted out of an engine.

I run 16X7 Panasports with (I think) zero offset. Car is lowered ~1.5" on Eibach springs and tire size is 225/50-16. No rubbing, except possibly a tiny bit on the frame rail at full lock.

Torque produced relates directly to engine efficiency (volumetric, combustion, etc). It's a measure of how effectively the engine uses the provided potential energy. Horsepower is a derivation proportional to torque and engine speed. Torque is the purer number, if you will...

Awesome project, I've been looking forward to seeing progress!

Yes. However, the results of combining intake and exhaust tuning are not linear. If under certain configurations an intake design gives an additional 5hp and the exhaust another 5hp, does not mean that combining the two will give you 10hp. The systems interact with one-another and the results of certain combinations can be surprising good (or bad). It takes design work and experimentation to get it right.

I can't agree to that statement because it is incomplete. Headers and collectors do a different job than the exhaust pipe out back, and the dynamics of their interactions with the cylinders are often misunderstood. Keeping pipe length constant, smaller diameter primaries will be more effective at a lower rpm and larger primaries at higher rpm. In the way that people like to talk about header primaries, I would say there is no such thing as going too big. People like to say X inch primaries are way too big for a certain engine, but how would they know if pipe length doesn't even enter the discussion? It's a well thought-out combination of pipe length and diameter which makes a tuned exhaust header/collector, and the tuned rpm range is dependent on both. A properly designed exhaust system will take into consideration multiple parameters, including a diameter which keeps pumping losses at a minimum, is physically able to be routed appropriately within the engine bay while minimizing bends, and a length which tunes to a certain speed range given the chosen diameter. If you want a peaky engine, then the above applies. Good engine designers will flatten out an engine's powerband by matching the induction and exhaust systems to different rpm ranges. As mention, intake length and diameter come into play in resonance tuning, exactly like exhaust tuning. This reminds me, I'm working on a spreadsheet that predicts tuned rpm (intake and exhaust) depending on your engine setup. I will verify it through dyno testing first before trusting it one bit, but if it's close then it can be used to predict tuned lengths of any engine setup. We'll see...

All tests are described in the FSM (Factory Service Manual), which can be downloaded from Xenon's site.

Not true. Not sure if you're familiar with the sticky in the exhaust sub-forum: exhaust tube sizing My apologies for the digression, but the myths must be corrected...

My memory is fuzzy on what's under the hood, but it may be a small block V8? I'm sure someone else will chime in with the details.

Funny, I have a Blaster 2 and was considering going back to stock! Glad you found your problem, now I need to fix mine!

Here it is: http://forums.hybridz.org/index.php/topic/90750-check-out-this-crazy-280zx/

Yes, that is the car. However, in your first post, you did not include a photo and you stated that it is a ZX, which it is definitely not. I think you're getting mixed up. I remember seeing a ZX for sale with a cheesy body kit and a "model" in the photos, but it certainly wasn't the Z in this thread...

No way, this is completely different car. This is one, of the 2 or 3, S30s with the "Primadonna" kit, originating from a backyard in San Bruno, CA. Search Primadonna Z for more info.

Pressurized fuel? There is already a line venting the float bowl into the air cleaner. What Tony proposes doesn't change much of anything, just lets you see the float level.

FWIW, you don't move any gears when you shift, unless it's into reverse.

1UZ with ITBs? I want!!! Great build, I'd love to see the details.

Nothing that google can't help with... A quick search reveals that you have a "Euro" 240Z distributor converted from points to electronic. Per-Lux is now known as Pertronix and still makes the conversions.