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Discussion Starter · #1 ·
A common thread that runs through the postings on this page is horsepower — how much people have, how much they want, how much each little diddle done to an engine will give. What I'd like to know is how you people KNOW you're cranking out 300, 400 or 500 hp — are dyno shops that busy? Or are these best guesses?

What I'd also like to know is what it costs for, say, every 25 horsepower. Just a ballpark figure. I imagine the first 25 or 30 hp is relatively cheap and easy with aftermarket bolt-on stuff. But beyond that, with cams, reworked turbos, etc., it's gotta start getting pricey. And 300 or 400 hp? That's gotta cost dearly. Can the Z platform actually handle that kind of power without twisting up like a pretzel? Don't you break stuff all the time?
 

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U B Exactly Key Rect

John,
You are correct about the cost of the horsepower. If you are going after serious NET
horsepower above about 200 it will cost dearly. Remember, the L28 makes a stock Net of about 135HP. The 280Z unibody, differential and axles and can handle 300 horsepower and more. This means the guys with the blown L28's and souped up NA's don't have to worry about the car handling it. Where the problem occurs is when the 'vette V-8 engines get dropped in. Actually a V-8 conversion on a Z is fairly straight forward and can be done woth no cutting onthe body. What gets exciting is the 350 ft.-lbs. of torque the motor develops and what it does to the car at low speeds. The other problem is finding rear tires that can handle it. The V-8 conversions are for either very talented back yard mechanics or guys with lots of change laying around. A good shop charge $10,000 parts & labor to do one right.
Phantom
 

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> A common thread that runs through the
> postings on this page is horsepower — how
> much people have, how much they want, how
> much each little diddle done to an engine
> will give. What I'd like to know is how you
> people KNOW you're cranking out 300, 400 or
> 500 hp — are dyno shops that busy? Or are
> these best guesses?

> What I'd also like to know is what it costs
> for, say, every 25 horsepower. Just a
> ballpark figure. I imagine the first 25 or
> 30 hp is relatively cheap and easy with
> aftermarket bolt-on stuff. But beyond that,
> with cams, reworked turbos, etc., it's gotta
> start getting pricey. And 300 or 400 hp?
> That's gotta cost dearly. Can the Z platform
> actually handle that kind of power without
> twisting up like a pretzel? Don't you break
> stuff all the time?

you know the saying, how fast do you want to go? well how much money do you have? I currently have over $10,000 invested in my motor and I am not even done yet. I hope to have it all complete by this summer.
 

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> you know the saying, how fast do you want to
> go? well how much money do you have? I
> currently have over $10,000 invested in my
> motor and I am not even done yet. I hope to
> have it all complete by this summer.

I think some people forget that all that power cannot be legally used on the road, so the track is where they must end up. So for some people it is a question of love for the car rather than power. Personally I like the Z for its style and handling. I'm just curious if there is anyone here interested in restoration and doing it themselves, rather than spending tons of cash. Don't get me wrong, I am not knocking the folks who have spent that much money or put in that many horses.
 

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Discussion Starter · #5 ·
I am cut from the same mold as Dave, I guess. I think the 1st and second generation Z cars are still among the best looking vehicles on the road. Since my '82 turbo has plenty of power for my needs, I also am more concerned with making it look and handle better than making more power.

I also have nothing against Z owners who want more horsepower. I was just wondering what it cost for a 400-hp engine and whether the car could stand it. I appeciate those who posted answers.

As for work, the only thing I've ever let anyone else do to my car is smog test it (I live in CA) and install a oxygen sensor when it wouldn't pass. Otherwise, I do all my own mechanical work, which often takes days longer than any professional shop, especially when I'm chasing down gremlins or trying to decode the shop manual. Most of the time I save a few bucks this way, get some satisfaction when I actually solve a problem, and have no one else to blame when I screw up.
 

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> A common thread that runs through the
> postings on this page is horsepower — how
> much people have, how much they want, how
> much each little diddle done to an engine
> will give. What I'd like to know is how you
> people KNOW you're cranking out 300, 400 or
> 500 hp — are dyno shops that busy? Or are
> these best guesses?

> What I'd also like to know is what it costs
> for, say, every 25 horsepower. Just a
> ballpark figure. I imagine the first 25 or
> 30 hp is relatively cheap and easy with
> aftermarket bolt-on stuff. But beyond that,
> with cams, reworked turbos, etc., it's gotta
> start getting pricey. And 300 or 400 hp?
> That's gotta cost dearly. Can the Z platform
> actually handle that kind of power without
> twisting up like a pretzel? Don't you break
> stuff all the time?

Only way to know for sure, it to put it on a Dyno. You can estimate, and with these engine, you can come real close. But if you want a No questions asked answer you have to put it on the machine.

I have a N/A 3.1 Stroker motor in my '82 280ZX, and I spent about $6,000. Nice large chunk of change, but I guess if you have your priorites sorted my way, it's all worth it! The only thing I seem to be breaking on a regular basis, are synchro rings in the tranny. (5200rpm speed shifting, and the brass rings don't get along!)

Are you building a motor? If so keep us all filled in, and how the project is going.

Chris behney
Redline Autosports
 

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John, everything is depending on the person and their car. One of the reasons that the Z's are so popular was due to there wight to HP ratio. They were fairly light for the times compared to the domestic cars. They also handled ten times better. Think of the 4200lbs SS454 Chevelle that only pumped out 385HP from the factory. At the same time the 240Z which weighed about half as much put out 150HP(??????). Cheap muscle car of the times.
As for HP the 1st 100-150HP is fairly cheap, only about $600. That will put you around 300-325HP. Add some bigger injectors and turn the boost up a little more and bamm 350HP. Add a bigger Turbo and some minor internal mods and you are to the 400-450HP range. Anything past this point looses streetablity and major internal modification is required. However a 600-700HP monster is what some people have pushed this motor to and some are even aiming higher. Cheap---nothing is cheap
 

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500+ hp

HP cost money. I am currently building my engine to produce 500+ hp. Most of us guess what we have, but you can't ever know unless you stick that bad boy on a dyno. I base my predictions on what has been done in the past to produce 500+ hp and by my own experiences. The first thing I have to buy that will allow me to make 500+ hp is a turbo that can deliver 500+ hp. I recently bought a big shaft 60-1 turbo w/ 4 inlet. This turbo is good to about 575hp. You can have a pretty good idea of what boost level you will need to run to deliver this hp. For me to make 550hp or so, I will need to run about 25 psi of boost. My last motor was making about 415hp, but more is always better. Let me break it down in cost to answer your question. This is what I have done to my motor and here are the costs.
$1050 - 60-1 big shaft turbo
$325 - racegate wastegate
$550 - 440cc primary injectors (280cc secondary injectors, had them laying around)
$350 - raceprep rods and bush for full float
$700 - Venolia forged pistons
$200 - Total seal rings
$200 - ARP head studs and rod bolts
$160 - HKS 2mm steel head gasket
$500 - Bell engineering 27x8x3 core intercooler
$200 - HKS racing compressor bypass valve
$200 - bosch racing fuel pump (good for 550hp)
$170 - TEP race cam
$100 - cam setup
$1950 - Electromotive Tech II
$350 - port-n-polish on head
$700 - machine work for engine (hone, turn crank, line balance, etc.)
$225 - Bell engineering rising rate regulator
$150 - intercooler piping
$200 - 3.5 mandrel exhaust
$250 - comp. valvetrain stuff
$200 - SS valves
$350 - Pro grip race clutch
Just these costs have come to $9080 and I am sure there are other things I have not mentioned, but this is a good estimate of what it would take engine wise to make 500+ hp. I will probably have to spend another $1000 trying to get it to the ground.
This is almost everthing, engine wise that it has taken me to have an engine capable of pumping out 500+hp. The engine will be complete in 3 weeks. I will be getting my rods back from top-end this week, and will need to get a line balance on the crank and the motor is ready to be assembled. Oh yea, I still have to get the cam setup done. These are only the costs incurred for building my engine, there are many other costs that are incurred to prepare your car to handle this hp. Anyway, that is my 2 cents worth.
 

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Re: 500+ hp intercooler size

> HP cost money. I am currently building my
> engine to produce 500+ hp. Most of us guess
> what we have, but you can't ever know unless
> you stick that bad boy on a dyno. I base my
> predictions on what has been done in the
> past to produce 500+ hp and by my own
> experiences. The first thing I have to buy
> that will allow me to make 500+ hp is a
> turbo that can deliver 500+ hp. I recently
> bought a big shaft 60-1 turbo w/ 4
> inlet. This turbo is good to about 575hp.
> You can have a pretty good idea of what
> boost level you will need to run to deliver
> this hp. For me to make 550hp or so, I will
> need to run about 25 psi of boost. My last
> motor was making about 415hp, but more is
> always better. Let me break it down in cost
> to answer your question. This is what I have
> done to my motor and here are the costs.
> $1050 - 60-1 big shaft turbo
> $325 - racegate wastegate
> $550 - 440cc primary injectors (280cc
> secondary injectors, had them laying around)
> $350 - raceprep rods and bush for full float
> $700 - Venolia forged pistons
> $200 - Total seal rings
> $200 - ARP head studs and rod bolts
> $160 - HKS 2mm steel head gasket
> $500 - Bell engineering 27x8x3 core
> intercooler
> $200 - HKS racing compressor bypass valve
> $200 - bosch racing fuel pump (good for
> 550hp)
> $170 - TEP race cam
> $100 - cam setup
> $1950 - Electromotive Tech II
> $350 - port-n-polish on head
> $700 - machine work for engine (hone, turn
> crank, line balance, etc.)
> $225 - Bell engineering rising rate
> regulator
> $150 - intercooler piping
> $200 - 3.5 mandrel exhaust
> $250 - comp. valvetrain stuff
> $200 - SS valves
> $350 - Pro grip race clutch
> Just these costs have come to $9080 and I am
> sure there are other things I have not
> mentioned, but this is a good estimate of
> what it would take engine wise to make 500+
> hp. I will probably have to spend another
> $1000 trying to get it to the ground.
> This is almost everthing, engine wise that
> it has taken me to have an engine capable of
> pumping out 500+hp. The engine will be
> complete in 3 weeks. I will be getting my
> rods back from top-end this week, and will
> need to get a line balance on the crank and
> the motor is ready to be assembled. Oh yea,
> I still have to get the cam setup done.
> These are only the costs incurred for
> building my engine, there are many other
> costs that are incurred to prepare your car
> to handle this hp. Anyway, that is my 2
> cents worth.

Hey, 240-- tell me how the size of the intercooler core was determined for your specific need.
 

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It's all a matter of balance.

> A common thread that runs through the
> postings on this page is horsepower — how
> much people have, how much they want, how
> much each little diddle done to an engine
> will give. What I'd like to know is how you
> people KNOW you're cranking out 300, 400 or
> 500 hp — are dyno shops that busy? Or are
> these best guesses?

> What I'd also like to know is what it costs
> for, say, every 25 horsepower. Just a
> ballpark figure. I imagine the first 25 or
> 30 hp is relatively cheap and easy with
> aftermarket bolt-on stuff. But beyond that,
> with cams, reworked turbos, etc., it's gotta
> start getting pricey. And 300 or 400 hp?
> That's gotta cost dearly. Can the Z platform
> actually handle that kind of power without
> twisting up like a pretzel? Don't you break
> stuff all the time?

I have seen two dyno charts, one for a 3.2L n/a L6 with [email protected] This was an all out race engine. The cam was @306 duration with over .600 lift. Pretty wicked, but not very streetable. A friend of mine who races in ITS, has a 240, bored .050 over with TEC II, and 3 exhaust. It puts out 250ft/lbs. This car is quite fast, but again, not very streetable, since it is so high strung, although it is alot more streetable than the 3.2L.
He actually has registration, so he can drive it on the street if he ever wanted to.

More common 'street' setups run about 220-260hp (gross). From experience and the wisdom of some serious engine builders, I've come to realize what some realistic expectations for power can be.

I would say 25-30hp (gross) costs around $600-$800. This includes a 2.5-3.0 exhaust, headers (NISMO ARE BEST), Cam. These mods would easily allow that much hp.

Remember, alot of L28 engines have lower hp ratings, because they are posted as net values, as opposed to gross. The reason for these low hp is because of a VERY restrictive exhaust 1 7/8 is quite small for ALL SIX CYLINDERS. Another problem is low c.r. A 8.3:1 is great for turbos, but for n/a, it totally sucks. 9.0-10.0 will really wake up a Z engine. Also, the 'Achilles heel' of the L series IMO, is the cam. These cams were designed to be compliant during the heyday of smog rules. They have ridiculously low lifts and durations. Just by changing to a 270/.450 lift, you'll improve hp, while actually improving efficiency.

Case and point:
My L28 engine has triple carbs, 2.5 exhaust (soon 3.0), headers and 270 cam. All smog equipment has been removed. When it was hooked up to a engine analyzer (for tuning) it only put out 200ppm more NOx than a 280Z. This is WITHOUT a CAT or SMOG PUMP. If I installed a CAT with the smog pump, I would probably put out LESS pollution than a 280Z, while having MORE hp. Just goes to show how inefficient the stock design can be.

As far as the Z platform handling 300+hp, it can do so quite easily. Remember a R200 rear is @8 which is plenty big. A Ford 9 is used in top fuel 1000+hp dragsters and such, and handles the power nicely. I would imagine a R200 in 300-600 would hold up very well. The only problem area I can think of would be half-shafts, as the u-joints are going to be enduring alot of torque. This is the only weak point IMO.
 

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Re: 500+ hp intercooler size

It is based on intercooler effeciency, pressure differential, the most important CFM. If you want to produce 500hp you need to be able to flow about 1.5*HP which is roughly 750 cfm. Any shop producing intercoolers will tell you the minimal requirements for intercooler size. In my case, I bought the biggest one Bell engineering had at the time that I could squeeze in the front of my car.
 

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240 Dave- How much horsepower does your 2.8 put out with the current set up. I'm going to change my cam to a bigger one, and i was wandering what sort of an improvement that i can look forward to. By the way what size carbs do you have.
Can anybody tell me what holley carby would flow similar fuel flow compared to triple 42mm webers,as i'm new to multy carbs and would like to know what i'm dealing with.
 

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> 240 Dave- How much horsepower does your 2.8
> put out with the current set up. I'm going
> to change my cam to a bigger one, and i was
> wandering what sort of an improvement that i
> can look forward to. By the way what size
> carbs do you have.
> Can anybody tell me what holley carby would
> flow similar fuel flow compared to triple
> 42mm webers,as i'm new to multy carbs and
> would like to know what i'm dealing with.

I haven't dynoed my own engine (yet; I will be this summer), but have talked to other racers and mechanics that built similar engines. Similarly setup engines run about 220hp (gross). This is with Triple webers, header, 2.5 exhaust and at least 9.0:1 c.r. Remember, a stock L28 with fuel injection puts out 180hp (gross), so a 40hp increase is about 20% which is about right. 240-250hp is obtainable with the additon of a cam and 3 exhuast. Remember, six cylinders are flowing through ONE pipe, this hurts higher rpm power, which is what the cam is creating. This is why you really need a good exhaust and intake, before messing with a cam, otherwise it's not going to do very much, as the rest of the engine is limiting the potential. Besides, a L28 makes plenty of torque for a lightweight 240, so the 3 exhaust doesn't really hurt driveability. And yes, I do know, because I've driven a car with 3 exhaust. It is VERY loud though, and has alot of resonance, so you may want to think about that.

I'm running 45mm Webers with 36mm chokes. Under 3000rpm is kind of sloppy, but once 3000rpm is hit, it really starts to scream. You can probably get a 4 barrel to flow pretty good numbers, BUT it was designed for flowing straight down, into the middle of a big V8. Not for use on a side drafted six cylinder. Consequently, Fuel delivery totally sucks with these setups, and no one I know will ever recommend this. It distributes the fuel unevenly, and makes the #1 and #6 cylinders run lean, which is a big NO NO. This is especially true for #6, as when it gets lean, it gets hot (since it's the last cylinder to get cooling), and when it gets hot, you'll start to see pitting and such in the cylinder head.
 

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240 Dave- Have you run your z over the quarter in it's current set up. The dyno that i've put mine on reads 125hp at the wheels. I think it would have to have more then that to run 15.3 sec quarters. The other question that i have for you is about my cam, it is a lift of .330. I am going to change it but would that be the reason that it won't go past 6000rpm. I'll give you a run down on the motor. 2.4l, e88 head with bigger valves, flat top pistons, triple 42 webers, twin point dizzy, 2.5 exhaust with a resinator into a 3 muffer and out.
 
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