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Discussion Starter #1
when does the turbo start to spool up on a
stock Z.
I almost always shift before 3500 rpm, is there
any reason for me to upgrade to a turbo engine.
Or should I totally squeeze every ounce of
power out of my NA 83?
 

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My T3 starts to make boost as low as 2200 rpm. However, if you always shift before 3500, then you will never use the power a turbo motor makes. Keep in mind that by going to a turbo motor, you will sacrifice off-boost performance because of the lower compression ratio. I am assuming you will use a stock L28ET which is 7.4:1. By doing this, you will most likely never even get the turbo to make boost because you say you almost always shift before 3500 rpm. I think you should stick w/ the n/a motor and do some simple bolt-on upgrades if you want more power.

Ian

> when does the turbo start to spool up on a
> stock Z.
> I almost always shift before 3500 rpm, is
> there
> any reason for me to upgrade to a turbo
> engine.
> Or should I totally squeeze every ounce of
> power out of my NA 83?
 

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Discussion Starter #3
Yeah, I just might stick with the NA. I was
either going to build a 270HP L28ET or
a 220HP L28. I know it would cost a lot of
money to do either but I know I could do it.
But I really prefer instant throttle response,
so I'm thinking normally aspirated here.
Thanks for responding.

> My T3 starts to make boost as low as 2200
> rpm. However, if you always shift before
> 3500, then you will never use the power a
> turbo motor makes. Keep in mind that by
> going to a turbo motor, you will sacrifice
> off-boost performance because of the lower
> compression ratio. I am assuming you will
> use a stock L28ET which is 7.4:1. By doing
> this, you will most likely never even get
> the turbo to make boost because you say you
> almost always shift before 3500 rpm. I think
> you should stick w/ the n/a motor and do
> some simple bolt-on upgrades if you want
> more power.

> Ian
 

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To get 220HP out of a L28E your going to lose some low end power. If I planned on shifting before 3500, I would not be so interest in making a 220hp NA motor. One reason is your 220HP is not going to occur until over 6000rpms. If you shift at 3500 your 220HP motor might only make 110HP. You'll want peak power to occur in a rpm range that you are going to use.
Just a suggestion:
1)increase compression: this not only increases total HP, but boosts low end power. Don't get crazy, I assume you still want to run pump gas, try about 9:1 -- 9.5:1 , I wouldn't go over that, unless you do some crazy head work, than you could squeeze about 10:1 on super unleaded.
2)Get a cam thats going to make a lot of torque below 3500 rpm. Yes this cam might not get your motor to make 220HP, but if you never use the upper rpm range the it doesn't matter if you make [email protected] 8300rpm if you don't use it. The motor with the stump puller cam will be a lot nicer to drive around town, have better fuel mileage, make a lot more HP and more importantly torque where your going to need it, below 3500rpms, but most of all give you more low end (below 3500rpm) accel than that 220HP setup.
3)A K&N ram charger is a must have. This will increase HP across the whole rpm range. One better is to get a early set of 240Z SU carbs and the matching manifold. If you go with the carbs you'll need a electric fuel pump, get a rotary style running at 4-6psi. I have a friend running the SU's on his L28 in his 240Z with a auto trans and this is by far the best the best power made cheaply I've seen. The carbs will give you (when in proper tune) instant throttle response + stump pulling low end.
(Options) A good header and free flow exhaust. Beware of bad designs. The Nissan Motorsports comp header is a exellent header but its designed for making power above 4500rpms (and this is the small diameter pipe one the other one makes power above 5500rpms). This isn't a good choice for you. My friend went to Tweeks and got a Thunderbird header. I don't know if this header is still available, but this header in combination with a custom made 2 1/2 single exhaust made a difference from about 2500-4000rpms and has huge power gains from 4000-6000 (this depends on the type of muffler you use). Generally a straight through design increases top end and decrease low end.
Keep the electronic ignition, its plently good for your application. You can spend big$ on aftermarket MSD setups, but thats up to you, if you got the $ to burn go get one but the increases in performance are only mild until over 5000rpms where you'll see the difference.
If you have extra $ left in the budget I definitely recommend a light weight flywheel. This is about the biggest boost for instant throttle response you'll get (and you'll feel the difference at any rpm range, low, mid, or high). The lighter the better. The only place I've seen with a true light weight (10lbs or less) steel flywheel is Arizona Zcar. There phone# slips my mind right now but here's there web sight address <A HREF=http://www.arizonazcar.com>http://www.arizonazcar.com</A>/
Aftermarket clutches are up to you, are you hard on clutches? Then I'd recomend the centerforce dual friction. It only costs a little more then a centerforce gold, but it last a lot longer and is a all around way better clutch.
Have fun with your project whichever route you go.
And most important enjoy the ride.
> Yeah, I just might stick with the NA. I was
> either going to build a 270HP L28ET or
> a 220HP L28. I know it would cost a lot of
> money to do either but I know I could do it.
> But I really prefer instant throttle
> response,
> so I'm thinking normally aspirated here.
> Thanks for responding.
 

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Discussion Starter #5
mucho de questions

Thanks for so much info. Although I know my
fair share about these engines, that was helpful.

For my HP goal, I was planning on keeping the
EFI. Add all the bolt ons: (I have the ram air), throttle body, headers, custom exhaust with
dynomax ultra flo, welded pipe inside catalytic
con.(no emissions test, but state inspection here)
Complete head job, tune ported intake manifold.
raised compression. Light weight fly wheel.
And an MSD 6-AL. I know this might not make
the extra 75 horses but it'd probably come close.

How would a RV-type cam work with this setup?
Also will a low end torque cam affect highway
driving, I frequently make 250 mile trips.
I average about 80mph the whole way (about 3400
rpm). What kind of affect will an RV type cam
have on this type of cruising speed?

What are the disadvantages of carbs (besides
getting out of tune). I kinda don't like losing
the advantages of fuel injection. But if carbs offer better gas pedal modulation I'd seriously think about it. Do you know of any company
that makes a better cam setup for the ZX?
Do carbs decrease gas mileage on our Z's?

I will rebuild my engine before I start to
increase the power. Since my engine only has
104,000 miles, I wasn't planning on touching
the bottom end. But with all that compression
and hotter cam, do you think I need to have the
crank shaft rebalanced plus add new bearings?

BTW, what else did your friend have on his
240Z that gave such a good power output?

Thanks again.

Antony Figueroa
 
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