Jump to content
HybridZ

Need just a little more power on a budget!


Nunavut

Recommended Posts

Hi, I have a clean 74, 260z 2+2 with stock motor, dual Webbers, 5 speed. She is ok at cruising speeds and passing but really all in all it’s gutless! What are my options to get some cheap bolt on power happening on a low budget? Can I bolt on a turbo to my Webbers? Or loose the carburetors all together and go FI somehow using used scrap yard parts from a 280FI block? my block is solid so I don’t mind taking a chance of loosing it as I do want to one day spend some serious coin on a SM chevy with 5 speed but thats not for a few years. I just want to bolt on something that will make a significant power increase without blowing my budget or my block!

What are my options here? I am in the Montreal area so I have tons of scrap yards with all kinds of wrecked vehicles that I can get parts from for next to nothing.

looking to get close to 200hp for now,

Any advice appreciated.

Thanks

Jay

8c01_3_thumb.jpg

8df0_3_thumb.jpg

Link to comment
Share on other sites

sorry, but performance on a budget is a myth. power costs money.

 

anyways, if you want to add a turbo, you'll either need to go blow through, meaning turbo, then through the carbie, then into the motor. advantage being that you can run an intercooler to help with inlet temps. Easier on the turbo too.

disadvantage is the carbie needs to be rebuilt to run under pressure, they were never designed to work like that, but its very possible to do. Usually the easiest way to do it is put the carbie in a sealed box, and just pressurize the whole thing, its a pain when it comes to tuning though, and the floats usually need changing, otherwise they crush under the pressure, and flood the motor.

Other method is suck through, so, carbie, then turbo, then motor.

 

Much easier, neater looking, no mods needed to the carbie, easier to tune, easier to set up.

Disadvantages is there is no possibility of using an intercooler, but the fuel air mix does help to cool the charge, so its almost a mini intercooler in itself.

the turbo also needs to be set up to handle fuel going through it, it needs a full face carbon seal fitted in the compressor to stop the fuel from permeating into the centre housing and into the oil supply (dilutes the oil and ruins the bearings)

 

you'll get more power again if you add in fuel injection.

 

If you just go with EFI, It wont be a major power increase, you'll notice a lot easier starting, better economy, better cruising and a bit smoother running, but its a great base to have in place once you go and drop an eight in there, to really unleash its potential.

 

For budget, id be looking at getting it breathing well, so a good flowing exhaust system, maybe some headwork, and a boxed off cold air intake to your carbs

Link to comment
Share on other sites

Headers and a cam or the two most traditional ways to more HP.

 

You can't go too crazy with the cam though or you could quickly lose good street manners. If you combine that with headwork, maybe even a bump in compression, then that is as far as I would go with the whole "budget" idea.

 

The cam and compression will have smog implications if that is an issue where you live.

 

A draw through carb turbo system will run into some $$ pretty quickly. May not seem like it at first but costs have a way of escalating once you get into a project like that.

Link to comment
Share on other sites

First check to see if what you have is working right. Timing, fuel mixture?

 

Then check the fan clutch and exhaust.

 

If all is well then ditch the Pinto carbs and get a proper set of early model SU carbs and then maybe a 2.5" exhaust with your stock manifold. (can add headers later) Then an electric fan.

 

Also note that the 2+2 weighs much more than a regular coupe of the same year. Not much you can do about that.

 

Alan

Link to comment
Share on other sites

260 2+2's came with 3.36 R200's, unless you already swapped it. If you already have a 5spd, the cheapest way to get some pep would be to swap in a 3.90 R200. Alot of people are after your 3.36 diff so you could easily end up making a few bucks in the end.

 

I have to disagree about the carbs. Although not the best, they aren't that bad. I had them with an L26 and had no problems hanging with a friends good running L28 240 with SU's. Check timing though.

Link to comment
Share on other sites

OK Thanks guys, everything is timed and running fine like a 2+2 does when motor is stock. I think I will start with a cam, header and better exhaust. Is changing the carbs really necessary? I have seen 4 barrel intakes, could a turbo not be adapted to one of those?

Jay

Link to comment
Share on other sites

Hi Clifton, bare with me here as I am new with Zs. yes I already had a shop swap the 4 speed for a 5 speed because I wanted better mpg. Are you saying I should now change my diff? and that my diff is worth allot more then the one I need to put in?

 

 

jay

Link to comment
Share on other sites

Your MPG will drop a little, very little with a shorter diff but with the 5 spd it will put your cruise about the same as with a 3.36 a 4 spd. Most performance mods won't increase mileage, except maybe hearder and exhaust. Here's some info. http://zhome.com/ZCMnL/tech/GearRatios.html You can find a S30/S130 3.54 or 3.9 at a pick and pull for around $50 all day long. You could even get a Z31 3.7, just have to change the pinion flange. Your 3.36 R200 is pretty rare. Depending on what someone is willing to pay at the time I would guess an easy $200+.

Link to comment
Share on other sites

First check to see if what you have is working right. Timing, fuel mixture?

 

Then check the fan clutch and exhaust.

 

If all is well then ditch the Pinto carbs and get a proper set of early model SU carbs and then maybe a 2.5" exhaust with your stock manifold. (can add headers later) Then an electric fan.

 

Also note that the 2+2 weighs much more than a regular coupe of the same year. Not much you can do about that.

 

Alan

 

I dont know about "much more" but it does weigh alittle more. Just imagine the difference of performance with driving your coupe by yourself and with a passenger.

Link to comment
Share on other sites

the differential swap will make a big difference in acceleration; if you still want more oompah, then I would suggest a mild cam and possibly re jetting the carburetors.... but to play games like this is to get into tuning, and from what I have read thus far tweaking your L26 is going to be an exercise in polishing a turd for you.

 

I couldn't disagree more; me no likey american V8, me likey Nissan OHC.. BUT, what I am saying is, you *could* get a cam and get some good advice from the cam grinder (or various internet forums, just not from me, I dunno carbs that well) on what kind of carb jetting to run with the cam.. or you could save the money you would spend on this, because you won't be getting much of it (if any) back. However, if you DO decide to go with a camshaft, then your carburetors will quite likely wish to be re jetted. In fact, it is possible that a simple re-jet could yield the results you seek by itself; but I am making a stab in the dark when I say this, I have no idea what jets are in your carbs now and I have no idea what would be best suited.

 

I know theory when it comes to carburetors, but I have zero experience.

Link to comment
Share on other sites

I wouldn't call an L26 a turd. They are nice motors.

 

Those webers are pretty good carbs. They have a lot of built in tuning capability. I ran them for 15 years after my SU's needed new throttle shafts. They sure have a lot more adjustments than the SU's did.

 

IMO the only real problem with them on a Z car is the way they have to fit on the intake manifold. That J bend is a compromise at best. In that respect I wish I had rebuilt the SU's , but no regrets.

 

People have a way of going to the extreme on this site. Like if it won't get you into the 10's it's not worth doing.

 

Just do the classic hot rod approach of headers and maybe a cam. Maybe an electronic ignition, or at least a module to replace the points. The ignition you can probably get used for pretty cheap.

Link to comment
Share on other sites

I wouldn't call an L26 a turd. They are nice motors.

 

I wouldn't either....

 

.....from what I have read thus far tweaking your L26 is going to be an exercise in polishing a turd for you.

 

I couldn't disagree more;

 

but my point was that, if he is planning on a V8 swap, spending good money on this motor is likely an exercise in polishing a turd. Apparently the L-series potential is not enough for him (or is too difficult to reach his desired power goal) SO; I made my metaphor.

 

Personally, I think that an RB is the only appropriate engine to swap in; I LOVE the L-series, to a point where it is "un-Hybrid-like" of me :rolleyes:

Link to comment
Share on other sites

yea, i definatley wouldn't bag a L26.

 

quick combo for you.

L26 block 83mm bore

LD28 crank 83mm stroke

use the standard L26 pistons and rods and chuck on an E31 head, and you have a motor with a square bore/stroke ratio, so great for revving and making power, and a comp ratio of 10:1

Run it on decent octane fuel, stick in a nice cam and adjust your timing to suit, get it breathing well and you'll have a quick motor that can still be very civil.

Wont suck down heaps of juice, and will still be very reliable.

If the E31 head is a bit hard to find, then you can allways use an E88 or N47 head and get a 9.6:1 comp ratio.

 

So pretty much all you need to do is swap the crank.

And if its not good enough, you could turbo it and see how long it lasts (not long at that comp ratio) or use the crank in a L28 block and build a 3.1L stroker.

Link to comment
Share on other sites

If your plans run on for a SBC in the future, figure out which transmission you got installed, early or late 5 speed.

If you have an early 5 speed, change to a 3.9 differential, and save your 3.36 for the V8.

If you have a late 5 speed, change to at least a 4.11 or 4.37 differential.

 

I have several 2+2's and none of them is geared lower than 3.7. The turbo car has a 3.7, the 2 N/A 2+2's I have have either a 3.9 or 4.11 in them.

 

The one n/a with a 3.9 in it, and early 5 speed returns around 22mpg towing a trailer that weighs 800#, with 750# of passenger weight in it.

 

Just remember these engines were meant to REV, I will pass people in THIRD GEAR at 65mph (and this is with an L28) tach out to 5300 or thereabouts and upshift. Thing will cruise all day long, 24/7 (and that is no boast, my wife and I drive in shifts on cross-country jaunts, so the car runs tank full to tank empty, stops for 20 minutes for gas up and dumping of fluids, and then goes again till it's repeated...) and return that kind of mileage. With an L26 it should be little diffrerent.

 

I have a 260Z coupe with a 3.7 and a late 5 speed...I got as high as 27mpg going through Wisconsin one vacation, keeping speeds down. The worst I got on that trip was the 1100 miles from Oglalla NE to Grand Rapids MI...where it had a triple digit average speed and STILL returned 19.5mpg! Steady State cruise can get you great mileage. And 19mpg at 100+mph average speed is phenomenal in my books!

 

This doesn't give you any power, but lets you put the power you have to better use. If you are looking for something that plants you in the seat when trying to pass someone in fifth gear at 70mph...none of these engines will do that. Just downshaft to third, and plant that foot. Fourth and Fifth just aren't acceleration gears in the N/A cars, compared with turbo and lager displacement vehicles.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...