Question for the Gearheads

[Drftn280zxt]

Okay I've conjured up this radical idea for my 280ZX's engine in the future. Tell me what you think and what kind of power could expected.

 

Take a reman L28ET and make a 3.1L stroker out of it. Use the P90 head with upgraded internals and a mild racing cam. Full port and polish job. Custom intake manifold. 650-750cc injectors. Billet fuel rail. Some kind of electronic (aftermarket) stand fuel management system. Upgraded fuel pump. NGK spark plug wires and spark plugs. After market distributor. Use a throttle body from a 240sx. Twin T03-04 turbos with upgraded internals,and adjustable external wastegates, BOV with recirculated blow off pressure. Intercooled with 3" mandrel bent pipe , water injection/CO2 injection (not sure which one is better exactly, I know CO2 is cooler). Custom larger diameter exhuast manifolds, down pipe to three inch diameter exhuast straight through design. As for the cooling system, large capacity aluminum radiator, oil cooler and an electric fan in front of both the radiator and intercooler. Also that engine mated with a 6speed tranny either aftermarket or from a 350Z.

[BleachZee]

First establish your budget and then decide what kind of engine you can build, not what you want.

 

Forget the 3.1L stroke, that's a waste. Do all the turbo upgrades though. Don't get a "race" cam, get a turbo cam with specific grinds for turbo applications. Maybe just pay a shop to build the engine for you.

 

[Scottie-GNZ]

Forget the 3.1L stroke, that's a waste.

Hmm, interesting. Although I would not go so far as to say a stroker is a waste, I thought I was the only one who thought it was not necessary. Unless you have an unlimited budget, the focus should be on the bolt-ons as that is where you get HP on a turbo engine, not from the internals. if you are going for 350+, forged pistons, headwork, mild turbo cam not "race" cam like Bleach said. You then put all your focus on the right combination of parts especially the engine management, I/C and turbo. And, remember, a turbo has 4 major components that can have an effect on how the car performs. Choose them wisely. With the right combination of bolt-ons, careful tuning and the required octane, you would be surprised how much boost you can run.

 

The way I look at it, a 3.1 buys you 10% displacement which in theory will buy you 10% increase in HP. I can get the equivalent with careful tuning and 2-3psi more boost that cost me nothing. I say save the money for the stroker and contact the Buick turbo community about adapting one of their alcohol injection setup to work on the L28ET. With that you run 23psi with 93-octane. You have not lived until you experience a well tuned turbo engine at 23psi or more.

 

Now, all the 3.1 turbo strokers that have been completely trouble-free, raise your hands.

 

Driftin, while your idea is not "normal", it has been done. See 240Z Turbo.

[Dan Baldwin]

 

But of course, with careful tuning and 2-3psi more boost on the 3.1, you again find yourself with a 10% advantage over the 2.8!

 

That said, if I were going turbo, on a schedule and on a budget, I agree that spending the budget on ancillaries is wiser than going the stroker route. But without time and budget constraints, I'd maximize displacement for sure. 10% is 10%, eh?!

[Pyro]

The problem with the stoker is than it is hard to get the compression down to 7.4:1 (besides costing money). Yes, more compression can be used but the L28 is prone to detonation.

 

One t3/t4 turbo is enough to make over 500hp plus it keeps the tubing down to a minimum.

 

Smaller injectors please. 500 hp needs 500cc in L28.

 

Intercooler piping can be small. 2 to 2.25" from turbo then 2.5 from IC to throttle body is enough for well over 400hp.

 

Too much HP is about as fun a too little HP. Aim for 300 to 400 hp with a turbo Z/ZX street car. Don't try make too much power because you will run into a bunch of walls (diffs, driveshafts, clutches, transmissions, and axles).

[JMortensen]

Why would you want a remanufactured engine to start with? So you would get to pay for a full rebuild, then you get to pay for it again to do all the same bore, hone, balance, replace pistons, etc to get it to 3.1L. BAD IDEA. I agree with Scottie on this one. Just get a normal turbo 2.8 and crank up the boost a little higher.

 

Why would you upgrade the distributor when you can get an engine management system that will use DIS and would be better than any distributor you could possibly buy?

 

Pusher fan? Puller fans are more efficient and move more air than pushers. Even if it is the exact same fan mounted on the other side.

 

6 speed transmission is a waste of money in your case. Not easily adaptable and gives very little benefit IMO. Just one more thing to add to the list of crap you've installed when you're at the NOPI car show.

 

At least you've dropped the "CNC a block out of aluminum"...

[BleachZee]

Maybe it would be cheaper to just put a 350Z engine and transmission in your 280zx and turbocharge that engine. They do make turbo kits for them now. Replace the pistons with dished and you have a 3.5L turbo. Then you can get right on your fiberglass bodywork and interrior redesign like in your drawings.

[Drftn280zxt]

Ok well first I want to thank everyone for replying that replied.

 

OK first off I think a 3.1L stroker engine with the turbos is higher prone to detonation. By adding Water or Alcohol or CO2 injection this possibility should be very limited if I am not mistaken.

 

It was mentioned that 500CC injectors are good for 500hp. Question, does the CC directly correlate the hp trying to be achieved. In other words would 350cc injectors be good for 350hp?

 

About the ignition system. I was not aware that a distibutor could be completely taken out of the engines composition. I am already learning new things.

 

It was mentioned that 1 T03-04 Turbo could push 500Hp. WHat about two? Another Idea what about two turbos one being T3-4 or T4 and the other being a T25 or T3. One for early boost the other for later boost.

IC piping I was thinking more along the lines of three inch. Why, well I'm thinking in whole, three pipe goes into the engine and three inch comes out. (very minimal restriction)

 

Too much HP is about as fun a too little HP. Aim for 300 to 400 hp with a turbo Z/ZX street car. Don't try make too much power because you will run into a bunch of walls (diffs, driveshafts, clutches, transmissions, and axles).

Those walls are important and will also be considered. By no means will thy be left untouched. My philosophy in modifying cars is that if you're going to put a lot of work into an engine than everything that works with the engine must also be

equally improved. I am an all or nothing kind of guy.

 

Another different engine is a big no no if you ask me. Your changing car to drastically. The heart of the car isn't from that type of car anymore. RB's belong in Skylines (its what makes the unique from other cars), Vq35 belong in those the factory intended them to be in. The L28 belongs in the 280ZX and that is where it will stay in my project (it will look slightly different though) but it is still an L28.

 

See the engine must be worthy of the interior and exterior. A flamboyant "racey" exterior/interior must have an equally imposing engine/drivetrain.

 

The CNC'ed block has not been ditched, if I could do it I would. I'm merely creating multiple possibilities ( or options).

 

Why a reman engine. No Miles! Longer life, more usage. A new engine would be most desirable. A used engine, is used for one, wear and tear has already taken a toll on it in some form. Better to start off fresh slate then put yourself into a postion where other problems could occur because of used engine.

 

AS for the fan aren't there puller electric fans?

 

So do you think a 5 speed is fine? (just upgrade in certain areas)(maybe a racing 5speed, or just ALum. Flywheel and better Clutch)

 

Keep bringing the input. Iam already learning new things. Thanks again for replying.

[JMortensen]

OK first off I think a 3.1L stroker engine with the turbos is higher prone to detonation. By adding Water or Alcohol or CO2 injection this possibility should be very limited if I am not mistaken.

So build it so that it doesn't tend to detonate. Lower the compression ratio, turn up the boost, retard the timing, and forget about the alcohol injection.

 

IC piping I was thinking more along the lines of three inch. Why, well I'm thinking in whole, three pipe goes into the engine and three inch comes out. (very minimal restriction)

I'm not even a turbo guy and I can tell you that the size of the outlet on the turbo is going to be quite a bit smaller than 3". I think most are 2.25". That's why it doesn't make sense. You'd have to run the 2.25" outlet into some sort of a expander to get to the 3". Come on man. Do your homework.

 

Another different engine is a big no no if you ask me. Your changing car to drastically.

You do realize what forum this is, right?

 

Why a reman engine. No Miles! Longer life, more usage. A new engine would be most desirable. A used engine, is used for one, wear and tear has already taken a toll on it in some form. Better to start off fresh slate then put yourself into a postion where other problems could occur because of used engine.

In that case you want a NEW engine. Is Nissan even making new L engines? A reman engine is a rebuilt USED engine. So buying a rebuilt engine then rebuilding it makes NO sense at all. A new engine is a waste of money too IMO. The parts that wear are the parts that are going to be swapped out during the rebuild anyway.

 

AS for the fan aren't there puller electric fans?

They're the SAME EXACT FAN. When you buy a fan they have instructions for using it as a pusher or a puller. Just requires hooking up the wires backwards and flipping the fan blade.

 

So do you think a 5 speed is fine? (just upgrade in certain areas)(maybe a racing 5speed, or just ALum. Flywheel and better Clutch)

I think you want a 6 speed just so you can say you have a 6 speed, but you don't realize the expense and difficulty of adapting one into your car. Plus you're talking about using the one with the notorious 3rd gear synchro problem. At least you could be talking about using something that is proven to be strong.

 

What the hell is a racing 5 speed? Something like what John Coffey has? A dogring 5 speed? You really wouldn't want that in your car. You wouldn't be able to hear your 800 lb 15000 watt stereo over the gear noise. Worry about building a motor that will break a normal T5, then when you get there worry about upgrading.

[JMortensen]

One more thing, your 240SX TB is 60mm, right? 60mm = 2.36". So you're going to have to expand your intake pipe up out of the turbo, then neck it down to the TB.

 

I did a quick search for you. Looks like the T4 compressor outlet is 2.5". So you can get a expander for 2.5 to 3 from the turbo outlet, then a reducer from 3" to 2 3/8" to get back down to the TB, if you really think that's the best idea...

[Drax240z]

Actuall jon while the 240sx is 60mm ID, it fits up really nicely with 2.75" tubing, as the OD of the TB is about 2.75". With my IC haivng a 2.75" outlet I chose not to neck down or up and made my cold pipe from 2.75 from outlet to TB. Waaaaay overkill for power, but easier & cheaper from the fabrication side of things. (sometimes we must make these concessions)

 

I still can't imagine twin t3/t4 hybridz on an L-series. Or at least when I do imagine it I picture a car that I can kill with my stock T3 under any normal driving conditions.

 

Lets see, on a 6 cylinder engine you can use 1 injectors flow rate as a rule of thumb for engine output. ie: 300cc/min~300hp, 550cc/min~550hp. It is just a rule of thumb for easy estimating.

 

A sequential turbo setup using a T25 and a T3/T4 does have some interesting appeal and could be viable given enough development.

 

Another different engine is a big no no if you ask me. Your changing car to drastically. The heart of the car isn't from that type of car anymore.

 

If you truly believe this I think you should probably consider 1 of 2 options. A) keep it to yourself here. Go find someone elses sandbox to piss in.

[JMortensen]

Oops, OD and ID, I guess. Well 3" intercooler tubing is going to be 3.25" OD? Maybe a little less if you use 3" stainless or some really thin wall tubing...

 

Do they force the 3" silicon hose over the tube, or buy a slightly larger hose, either way, still going to need to neck it up and then back down...

[BleachZee]

On the twin turbo idea; dont' use different size turbos. The whole point of a twin turbo setup is to acheive those high horsepower numbers, and use a pair of smaller turbos. The smaller turbos will spool up at a lower rpm and give you torque faster like you want. But since there are two of them they can still pump out the higher psi than if there was only one. Well, plus twin turbos work well on "V" engines but that's not the case here.

 

So is your goal 800hp? Or do you just want all the goodies to have a nice fat list of mods? If you want 800hp, I think you got the wrong engine... honestly, but I do like the L28. If you want 500hp then you'll be hard pressed to get that from an L28 turbo before you go blowing stuff up every year. My suggestion is use the T3/04 hybrid, keep it to a single turbo and build it as others suggest. You'll have 400hp or close to it and your engine will last more than 6 months. You won't be able to put the power down with the Z's suspension so going with more power than that will be pointless... then you'll be in the area of Scottie, that guy that swaped in the Corvette rear.

 

Ok, so you're a guy who goes all the way or nothing at all. How many L28s have you built? And can you go over some of the mods you did on that engine and what you thought about it? ...even if it was an NA motor

 

Oh, and the T5 is a good transmission. With that kind of power though you're going to want to just put in a higher geared rear. Either Keep the 3.54 and put an LSD in it, or go up to a 3.36 and mod it for LSD. The 5-speed will be fine. There are also aftermarket kits for the T5 that can increase the strength. The stock T5 is good for 350lbs, right? so about 350hp or so. However, the R200 is good for about the same. If you go with 400+hp you'll blow the rearend. Corvette time

[Drftn280zxt]

WOW! I get a lot of strict criticism.

 

Alright, if I'n not mistaken as far as engines go. NO turbos=high compression, Turbos=lower compression.

 

As for the I/C piping, good point on the size, I didn't think about that at the moment. Having consistent tube size is more important that trying to achieve 3". I do a lot of thinking out loud before thinking about it on the computer for some reason.

 

Yeah I realize what forum this is. The one that actually helps people. Sure a lot of guys here do V8 swaps and I think thats awesome and I highly respect and awe their cars. But, if I saw an L28 pushing 500+ HP next to a V8 pushing 500+HP, I'd be more interested in the L28.

 

Moving along, the engine block, if you buy a used junkyard engine you the the rish that everything could br defective, reman? well less things would be defective. My major concern is having a good foundation, a good "perfect" engine block.

 

The dan thing makes perfect sense to me, I can't believe we had the discussion.

 

I'm not pissing in anyones sand box. Merely voicing an opinion that is very minute. Well no that the cats out of the bag I don't need to say it again.

 

No I don't want 800hp more like 500-650hp. This number can always change though. Deciding how much power I'm comfortable with is still pending. I want enough power to send chills down my spine but not so much that it scares the crap out of me. So far the most power I've put to the test in another car was 400hp. That was pretty intense but not enough to severely scare me.

The goodie list is desirable.

 

How many L28's have I built? Well one. It was my friends engine and it was a combined effort. Mods were minimal. More along the lines of a rebuild to be quite honest. So I really don't have a ton of experience at all.

 

I'm only 18 years old. These additions ar right now merely day dreams but I have good intentions, of course we all probably say that?

 

This engine is like a math problem with 50 variables and I'm trying to solve it so that is gives the correct answer.

 

-Goals of the engine- approx

500-650HP

500-650 lb/ft of torque

17+ PSI of boost

[Drax240z]

The whole point of a twin turbo setup is to acheive those high horsepower numbers

 

I don't buy that for a second! If you want peak HP lots and lots of people opt for twins. I think the big draw of twins (and sequential setups) is the chance to achieve a large power bump while still retaining a fairly linear power curve.

 

No I don't want 800hp more like 500-650hp. This number can always change though. Deciding how much power I'm comfortable with is still pending. I want enough power to send chills down my spine but not so much that it scares the crap out of me. So far the most power I've put to the test in another car was 400hp. That was pretty intense but not enough to severely scare me.

 

400hp in a 2800lbs car driven by someone that can REALLY drive is pretty darn scary if you ask me. (granted scarier if the person cannot drive, but for different reasons) Power to weight ratio of 7lbs:1hp. I believe an Enzo Ferrari is just about 6:1. You are talking about building a car that is in the low 4:1 range.

 

Granted there are lots of drag cars with better numbers than that... but that is one 'scare the crap out of anyone street car' in my books.

[BleachZee]

The whole point of a twin turbo setup is to acheive those high horsepower numbers

 

I don't buy that for a second! If you want peak HP lots and lots of people opt for twins. I think the big draw of twins (and sequential setups) is the chance to achieve a large power bump while still retaining a fairly linear power curve.

Don't cut my quote off so quickly. That's exactly what I explained in that paragraph. Faster spoolup as well as the higher hp numbers. You explained it with one word by saying a more "linear" power curve.

[JMortensen]

Moving along, the engine block, if you buy a used junkyard engine you the the rish that everything could br defective, reman? well less things would be defective. My major concern is having a good foundation, a good "perfect" engine block.

 

I tried...

[Drftn280zxt]

Okay I've conjured up this radical idea for my 280ZX's engine in the future. Tell me what you think and what kind of power could expected.

 

Take a reman L28ET and make a 3.1L stroker out of it. Use the P90 head with upgraded internals and a mild racing cam. Full port and polish job. Custom intake manifold. 650-750cc injectors. Billet fuel rail. Some kind of electronic (aftermarket) stand fuel management system. Upgraded fuel pump. NGK spark plug wires and spark plugs. After market distributor. Use a throttle body from a 240sx. Twin T03-04 turbos with upgraded internals' date='and adjustable external wastegates, BOV with recirculated blow off pressure. Intercooled with 3" mandrel bent pipe , water injection/CO2 injection (not sure which one is better exactly, I know CO2 is cooler). Custom larger diameter exhuast manifolds, down pipe to three inch diameter exhuast straight through design. As for the cooling system, large capacity aluminum radiator, oil cooler and an electric fan in front of both the radiator and intercooler. Also that engine mated with a 6speed tranny either aftermarket or from a 350Z.[/quote']

 

Okay now for the more logical setup after your massive amount of input.

 

-Get a new engine block (if possible) from Nissan (bore it out and increase the the stroke length via a new crankshaft, LD28) (gaining ~3.1L Displacement)

-forged pistons (new rings also), high performance turbo camshaft

-Get a used or New P90 head and seriously upgrade it with new internals.

also do extensive porting via professionals or outside training (not sure about this one) to increase and smooth air flow transitions through the head.

- 400-650cc injectors, electronic stand alone fuel management system to replace the old technology

-60mm TB.

-twin T03-04 Hybrid turbos or a small T25 turbo and a T3-04/T4 turbo

-electronic boost control

-17+PSI of Boost

-60mm IC piping

-large IC (not sure on measurements)

-large aluminum radiator

-electric puller fan for better cooling

-oil cooler

-upgraded T5 transmission with Aluminum Flywheel and high performance Clutch (ACT, SPEC, or some other company)

-if necessary water injection/(CO2 Injection for racing,= colder air, higher RPM= more power).

-high capacity Fuel pump, aftermarket fuel regulator, and billet fuel rail

-custom intake manifold, for increased air flow and smoother transitions

-stainless lines/silicone hoses used wherever possible

-custom exhuast manifolds (headers) [(3-1) to a turbo->(2-1)to exhuast<-to a turbo(3-1)]/ custom downpipe to 3" exhuast

-upgraded computer (either performance chip or custom altering, someone on Zcar has figured out how to modify them) or just a whole new computer (I've gotta research this, not sure if its possiblem but an idea for sure)

- almost forgot the BOV (with recirculation, I know this means just adding a hose from the BOV to the intake). (not sure waht would be best for the scenario as for the type of BOV(I'll research it eventually))

 

remember this is only brainstorming.

 

Not that I'm really concerned but for the heck of it what would gas mileage be like? (I guessing 6mpg-12mpg , it is said turbocharging increases MPG under normal driving condition (my driving probably wouldn't be normal very often ))

 

don't foget that the concept bodywork would give the engine better cooling all around!

 

Thanks for the replies and criticism again, I appreciate all of it whether +/-. Its all neccessary and I try to keep my ego out of it.

 

so it this more logical? or still stupid/crazy/illogical? (please fill me in on the specifics)

[BleachZee]

My opinion is:

 

Forget about stroking it. You're wasting time and money doing that.

You can get 500hp from 2.8L Think more "high rpms" / less stroke.

 

-Megasquirt is an option for a programable computer

-Everything else is ok.

[Dan Baldwin]

My opinion is:

 

Forget about stroking it. You're wasting time and money doing that.

You can get 500hp from 2.8L Think more "high rpms" / less stroke.

 

The rpm potential you gain with the shorter stroke is less than the displacement you lose. Assuming custom forged pistons and bottom-end rebuild anyway (500+hp, right?), stroking shouldn't raise the cost much at all relative to total project cost. 5% more stroke = 5% more torque everywhere, at the expense of ~3% rpm potential up top, assuming peak piston acceleration is the limiting factor. I'd rather have the 5% everywhere than 200 more rpm up top.

 

That said, for a first-time turbo build, I'd plan on more modest hp goals and build on a JY 2.8 turbo bottom end and get some experience with building a turbo before risking a bottom end with a lot of time and money invested in it.