What do you find to be the sweet spot?

[Guest kealokian]

I'm looking to start a project pretty soon.

I've begun research and have acquired a 1973 240z.

 

My current proposal is to get an ls1/t56 and the JCI kit.

 

I was wondering what you guys find to be an ideal horsepower range?

I want to push the limit, but also want to be able to hook up.

What do you think one should shoot for horsepower-wise

(in the long run, i'll start with a stock ls1 and upgrade it with time)

without going overboard?

 

Hope this is a legit question.

Thanks for any advice given.

[Pete84]

You probably want to clarify what you'll be doing. 1/4, street, autox, and what sort of tire you are willing to run.

Also, how much you are willing to spend on the rear diff. The stock isn't going to take much abuse, and on the high end the R230 is pretty spendy.

I won't be able to help you on the hp / tq question though.

Wish I had the Z experiance to be able to though

[Guest kealokian]

Good point.

 

I wouldn't mind getting into auto-x, but i think

mostly, it will be a weekend warrior/cruiser.

 

I'd take it to the drags, but i really want to be able

to go tear it up on back roads and the like. That's really

what i ultimately want to do.

So i guess in the end, i'd be more looking at a auto-x style build

than a straight line racer.

 

Also, i meant to mention, i am open to other ideas regarding the power house.

I hear bad things about going the ls1 route, cost being the main one.

And cost of upgrades as well.

I just can see it being more legitimate for longer road trips (if i were to do so).

 

Sorry if i seem aimless, i've still got quite a bit to pick up on.

Thanks for the help

[blueovalz]

Horsepower is money, and I think it is true that all of us pretty much put as much horsepower into the car as we can afford...no news there.

 

The typical manuals and books on handling will provide you with 90% of the info you need to steer you in the right direction for this. Most of us stay in this "aftermarket" support category, and that looks like a good place for you to start as well. Take some time and read the forums that deal with the handling, braking, and suspension issues and you'll eventually form an pretty good idea of what you want or need, and any gaps in this information (the main issues are covered well with the stickies) can be addressed as you decide on the direction you wish to take.

 

Lastly, make the modifications that make sense, and not for the "gee whiz" factor, which can be pretty simple, but effective. You need to know exactly what you want before you get started. This will save you money in the long run.

[DHale_510]

250hp with mostly stock suspension and tires that fit a stock fender well, 300hp with pretty expensive suspension mods and wider fenders [and tires] is about all that a Z can really hook up. Wheelspin is the primary result of more.

Then again, the only time that there is too much horsepower is when the other guy has it....

[EvilC]

250hp with mostly stock suspension and tires that fit a stock fender well, 300hp with pretty expensive suspension mods and wider fenders [and tires] is about all that a Z can really hook up. Wheelspin is the primary result of more.

Then again, the only time that there is too much horsepower is when the other guy has it....

 

The LS1 powerplant will/should but down over 325 at the wheels. Therefor you are starting with plenty of power. I am running 245/40/17 that just fit in the stock fender and should be "ok" to take care of some wheel spin. There are guys putting down crazy numbers with the lsx motor series and it comes down to how much time, money, and use of the car that will limit your hp numbers.

 

Cost of an LS1 swap can cost lots of money depending on how you tackle the swap. There is a thread going on right now about parting cars out. If you have the time and drive...it is possible to pick up the motor/trans/pcm/fans/harness for FREE. That will take care of 3-5k and money that can be spent somewhere else in the car. Lots of info here on the site plus a new sticky that will save you time and money.

 

More important...what kind of shape is your 240z in? Rusty? Any pics? The shell you start off with should be accounted for in the price of the swap. You may need to reinforce the chassis and more......hope this helps.

 

Clive

[280zwitha383]

I say build for more hp than what you will need/want. You can always go easier on the peddle. ::::caughboostedv8cough::::

[DHale_510]

>You can always go easier on the pedal.

 

Really? I never can....

[Guest kealokian]

I'll get some pictures asap!

 

But the condition of the vehicle doesn't seem too bad.

There is a small hole in the floorboard under the driver's feet-ish area.

 

I also know of rust inside the passenger side door panel, but i can't recall

if it was very bad or not.

 

Regarding the ls1 powerplant, my concern has become modding the motor, because of the cost. But the fuel efficiency is quite attractive at the same time.

 

 

I think i want to shoot for 300-350 to start, and i'll build more power as i want/as my friends start to get faster than me.

 

245's is a good size and if they can hold the traction pretty well, then that's all i really need. Wheelspin is good, too

[EvilC]

Well the stock LS1 motor will put down over 300 at the wheels. Most guys here are getting 30+mpg highway use. Also for the price nothing beats the JCI motor mounts...for the lazy like me buy the tranny mount if you have fab skills, make your own. 245 is a great size and you can get some very very sticky tires. Can't wait to see pics of the car.

 

Clive

[Michael]

Mention was made of getting adequate traction, and reinforcement of the unibody to support a particular level of spirited driving (which, the racers tell us, has more to do with a stiff suspension and sticky tires, than with a high-torque engine).

 

But what about the cost of building up the engine and driveline? There is a "knee" in the curve of hp vs. $, and it depends more on the choice of engine and skill of the builder, than on the choice of car into which the engine will go. In other words (and this will be controversial!) the cost is roughly the same in a Chevelle as in a Z. I mean, a $7000 SBC Chevy (or whatever engine) doesn't know into what chassis it was bolted into.

 

But then there's the assertion that the Z is lighter, so less power is required for the same performance feel, relative to a muscle car. True, but does a 350 hp engine cost that much more than a 250 hp engine? What about a 450 hp engine? Again, the point is: consider the potential and the cost of the powerplant first, and don't worry (at first) about Z-specific engines.

 

In my case the swap itself was relatively straightforward, but care and feeding (and repair and re-repair!) of the engine is interminable!

[strotter]

Something else to consider when doing the engine build: the "livability" quotient. The more you mod the motor, the more you need to fiddle with it to get it right and keep it right. My 350 is in the 350/400 hp range, and is a bit on the "tightly wound" side. Tuning the ECM is a complex and seemingly never-ending job. It's not undriveable, or even unpleasant to drive, in fact just the opposite; but it's fatiguing going back and forth to work, to the grocery store, to the barber, in the heat, in the rain. It's great to have a powerful car, but it should be built in such a way that you can ignore it when you please.

 

Also: my experience has been that factory anything is more reliable that aftermarket items. Headers, fuel pumps, injectors; factory stuff may not make the most power, but they work when you need them to. More fun cutting an apex than reinstalling some gasket for the ninth time. To me, that's the greatest advantage of the new V8's: they don't make the most power, but they make very good power in near-stock trim. If you don't trust it to get you home, you won't take if far, or often.