I've had my ZR for a year now and have done some reasonably extensive mods. I spent all last winter when my car was happily garaged installing a Stoptech 4-wheel brake kit, a full Nismo suspension, a 75 shot NX kit, and Veilside front lip. I also had some beautiful color-matched headlights made courtesy of clear-corners.com.

In thinking about going to "the next level", this upcoming winter, I am really thinking about working with a completely new engine block and parts. Now....FI or highly tuned NA? FI would certainly be easier, but I do feel the power delivery is hard to control in this car. Also, many peoople have gone this route. A highly tuned NA motor seems to be territory that less people have tackled and therefore, this is actually more appealling to me. So.....what's the latest with high-end NA? Who's done what so far? I'm thinking about higher compression, upgraded internals and crankshaft, and maybe independant management with an integrated controller like AEM. Only issue is that it has to pass OBD based emissions testing, and I really don't want to spend more than about $25,000 to build this motor. Again, it's not about the most power, it's about a modest power bump and doing something that not as many have done.

All ideas and suggestions welcome. I will look at what everyone says, do some extensive research and plan the project for this upcoming winter. Since I live in the Northeast, and own a roadster, I really don't want to sacrifice prime driving time modding my car in the spring/summer although having a whole new engine to work with will certainly help me to get a little earlier start.

 

FI is definetly easier to make power with. I think alot of the people complaining about blown motors and problems with FI are either raising the boost without having internals or other work done, or they got a crap tune. However, I did not have enough money to put down 7-8k all at once for a kit install and tune with minimal goodies. FI will nickel and dime you to death on the small stuff.

With that said there isn't much science in getting a good N/A setup. Breathing mods are a good place to start: Headers, High Flow Cats, Y-Pipe, Exhaust, Intake etc... After you have all this small stuff outta the way I would say go for a decent size cam. I am eyeballing the Tomei 268s. I think someone did a review on these and the insane power delivery over 4k rpms sounds alluring. Stuff to look for:

350EVO's Intake Manifold
350EVO's Headers
Individual Throttle Bodies

Best Motoring (http://www.bestmotoringvideo.com/) features alot of nice N/A cars so it's a good place to look for ideas. Togue Battle is badass.

 

I saw an article where the Esprit Z that was stroked to 3.8L (11.5:1 CR) was showing some considerable speed on a track, passing a 911 GT3 without difficulty (at least so far as the article described). I think this would be a fascinating route, and you're right, there seem to be way fewer highly modded NA Zs on here. If you're doing it though, stroke it, use either the Esprit 3.8L($$$!) or AEBS 4.3L and see where the Z can go if you give it some displacement. Go for it! And keep us informed, I'm all for you spending your $25k to satisfy my curiousity...

 

Having a highly tuned NA would be great, but so far I have not seen one with over 300whp on the boards, and so I'm not sure how high you can go. I would suggest to go FI, even if there are already a lot of FI Z's. And I'm not being biased here, but I wanted to stay NA as well, but then when I saw I spent about as much money on NA mods as I could've spend on a Turbo, and I only gained about 40rwhp, it just convinced me to go the Turbo route.

Boost is something you get addicted to very easily!! About controlling the car, its not so bad... all u have to do is keep it below the rpm at which boost kicks in, or don't let the full boost kick in. However, since its so addictive, you will be punching it at almost every open road you see I use my TT Z as my daily driver and I've also upgraded my clutch and flywheel, so it revs and accelerates even faster, and I've had no problems driving the Z in the city or anywhere else.

Finally the price issue... for $25K you could easily build a monster TT Z and still have a little left for a body kit, if you want one. With $25K, you could do a lot of stuff to a NA Z, but you could nowhere get it as close power wise to a FI Z with the same amount of money, even if you spent more money, I'm still pretty sure that it couldn't compete with a FI Z power wise.



Jaki

 

im finishing up a build myself on my engine hoping to accomplish 600WHP.. or a little over 700 at the crank..

Who ever said FI will nickel and dime you to death was more than correct ... its expensive...

If you want easy power gains this is the way to go... but has proven unreliable at the moment when it comes to turbocharging. There are a few new promising companies that are coming out with new systems that have done well so far taking care of the issues other companies were having (APS, Turbonetics, SSR Engineering). Although i dont know of any problems yet... give it some time to see if they are reliable. If you like the idea of FI, what do you think about supercharging? So far they are tremendously more reliable than any FI kit out there.... besides the ATI system, they had some issues with no timing adjustments...

Basically the more power you want... plan on it being less reliable... building an engine takes a VERY VERY long time unless you have one on your hands... so far im up to 9 months and im still not done. But my power goals are high. If you want somewhere along the lines of the 350WHP range... go with a more reliable supercharger... In my opinion..... they are all more reliable and will throw you back in your seat....

If you want more than that... and let me tell you... you wont ever be satisfied once you learn how to drive with your new power... whatever you put on give it a couple months... while your friends crap themselves in your passenger seat not knowing what the hell is going on because they never went that fast... you'll be sitting there emotionless trying to figure out how to get more power as you let out a yawn...

make a plan on what your goals are and do it right... dont spend a fortune relpacing parts. I'm biased myself towards FI... because every car ive ever driven stock was NA... and it was just "OK"... i even drove around a viper... that extra throwback you get all of a sudden from FI is way more exciting in my opinion.. and when your not on the throttle its more fuel efficient then a larger NA engine. But like i said thats just me.....

 

I'm also interested in how far Z can go with NA.

I say.. AEBS 4.3 stroker kit (Includes all the forged internals with 11.5:1 CR)
With a radical profile cam (Like.. Tomei 272 or Custom spec cams?)
And Standalone ECU is a must. (HKS Fcon Vpro seems the best)
And Return Fuel system (CJ motorsports or AAM)
And other stuff I don't know about.

With all these mods, I think Z can achieve about 350rwhp hopefully. (Just a guestimate)

For hp/$, it'll be nowhere close to FI but well, at least it's exotic and I still prefer the highpower NA rather than FI engine.

Ahh.. only if I had enough $$..

 

I hadn't heard of Tomei having 272 cams, I've only seen 268. I agree that it seems NA is a waste of money. So here's my idea (and others can pitch in on it's ridiculousness): Could you not get the AEBS 4.3L stroker, but get custom pistons (something like a 10.5:1 or 10:1 CR) and then slap a Vortech on it? If stock internals are handling boost, why wouldn't the forged internals of the AEBS hold at least the same amount? Maybe I'm completely off here, but the JGTC Z (I know, different engine, completely different playing field) uses high CR plus the boost, since it can't afford the lag (it still has high enough CR that it's got some kick without boost).

Couldn't we go stock CR or a little higher, on forged internals, and get a 4.3L Z that also had the headroom of mild Vortech boost? I know this thing would be damn expensive, but this guy's still talking $25k, and I'm interested. Another 800cc is considerably more engine to cram air into...

 

ummm, i really can't believe i'm seeing what i'm seeing. you have 25k to put into your motor and want something that an f/i guy could walk all over you with? i mean every one has their thing, but seems like a bad way to maximize your dollar spent. why not do a turboed aluminum small block chevy and put a narrowed solid axle rear with tubs.
that would be awesome!! if i ever wreck mine, that may be what my Z turns into. hahahah.

 

I think the point is being missed. Not everyone wants, needs, or can use 500whp. I think a pretty good driver would be hard pressed to take full advantage of even a 350whp Z on the track. I'm not talking straight lines, I'm talking turns. I see people throw together 600whp Supra's with an out of the box set of coil overs (stock dampening and valving, blah) and think they are a track monster only to be beat by someone with significantly less hp all through the turns. Obviously F/I would give you more HP/$ eventually but how much hp do you really need? All it's good for is straight line. I think one of the best Zs on this board is ZIllinois' N/A Z. It's a really balanced machine with all the parts working together, I could imagine he could take down his fair share of F/I monsters at the track.

 

NA all the way since I am curious as well. I am going the NA route and will eventually bump the compression, but I dunno about the displacement yet though

 

Great point! Which is why I am staying NA for reliabilty on a track course. 325-350whp is my goal at the moment since anything more than that would be hard to control around a tight turn at buttonwillow I just came up on some money and could have easily purchased a Turbonetics Turbo Kit and slapped that bad boy on, but I kept picturing myself breaking at a track event after pushing it hard , so I went and ordered some Gears and a LSD

FI is great for HP dyno queens and straight line, but just like he stated, many with high HP get passed at track events every single time It is better to refine your driving skills and work on suspension and weight loss

 

For me, it's not just about speed. Believe me, I 've done that in a previous car. 25lbs boost in a modified Audi S4 with well over 500lb-ft of torque. With all-wheel drive , my 1/4mile was consistenly in the low 12's with my fastest 0-60 radar clocked at 3.9 seconds on 103 octane. It is awesome. I just want to do something different. I enjoyed driving a Honda S2000 more than a Viper, because of the "feel" of the car. I bought the Z not for maximum power...I would have just kept my S4 for that. I wanted a convertible, and this car is just plain drop-dead gorgeous and still a reasonably balanced package right off the showroom floor. If it wasn't such a damn good-looking car (yeah, I know, I'm shallow), I would have spent the extra $$$ and bought an M3. I want smoothness and predictability in my power delivery. If I can get 300rwhp NA with a beautifully revving motor, I will be happy. I want to do NA just for the fun in the project and the satisfaction of getting something like this working well. Do you know what I mean?

 

I would go with the AEBS stroker and then the standard intake, plenum, pulley, differential, cat, exhaust, header, plenum, ECU, and clutch upgrades.

You are looking at 350rwhp no problem.

 

Exactly. TT kits are awesome because of the expandibility of their power outputs, but I'm choosing to go N/A because for the most part, N/A is much cheaper than a full TT setup (Kit, installation, build, etc.), it is a linear powerband, and I don't need 500 whp on a daily driven car.

Now a car that can run mid 12's N/A, look great, handle great, and be reliable... I'll take that.

 

once the new heads are on my car and the ecu retuned I am hoping we'll break that 300 whp level. Should have the heads done in about 2 weeks, then anothjer week or so for the install at night, and finally install and tune the F Con....fingers crossed it gets me where I want

 

subscribing.

 

that would be cool

but problem with the stroker kit is it'll cost you big time.


kit is $8000

getting the kit installed and your engine taken in and put back in will be around 4000ish?

need new fuel system - return fuel system, fuel pump, injectors, install = 2000 or so

custom ECU tune or EMS - not sure on $ for ECU tune, but EMS will be 3500-5000

=$17500-19000 for NA 350-365whp

the stroker kit's sleeves get hot because of all the solid metal

the middle of the piston chamber gets really hot because of how much it's being stroked



that's an expensive engine if something were to go wrong...

hypothetically, say you blow up your engine block in a FI vs stroker NA kit scenerio due to detonation or preignition or whatever.

with FI and a built up engine, even if you somehow blow your block up, at most you'll lose $7000 for block, forged pistons, rods, darton sleeves (if you need over 600whp otherwise dismiss $1500 from the total), rod bolts, studs, head gaskets, and around $2000 for install
= $9000 loss, $7500 or so without sleeves

with the stroker kit, you're losing $2000 engine pulling and install labor, up to $8000 in stroker kit parts, $2000?? stroker kit install labor, $2000 block
= up to $14000 lost on a blown stroker engine

there's very few stroker kits out there to know just how reliable it is out on the track. In theory the stroker kit should be fairly reliable, but if you properly set up a FI car, it should also be reliable - just a little more maintenance, but if you track your car, you probably already change oil etc more often than normal anyway right?

 

Why not just sell the Z keep all that extra money your gonna dump into it and buy something that can be made fast for a lot less, pick up an 06 vette and do a full exhaust and some tuning and you'll be way faster than an FI Z probably in the end for about the same cost. I just fail to understand why people buy a $30,000 car and drop $20,000 to make it faster when you could have just spent the $50,000 from the get go and had a faster car to begin with. Mind boggling.

 

can't we have both, the best-looking car on the road AND one of the fastest, too? looks-wise, there is not another car i would want. performance-wise, i want to make it faster. is there anything wrong with that?

 

i have 2 vettes, one coupe one vert. the coupe is 700 crank hp but going to sell it as i am now doing a built motor tt set up in the z. the vette rattles a bit and does not feel as solid of a road car. plus imo the Z just looks better to me and well all the ladies think so too, hahahha.the Z is now my fast car and will hit about the same crank hp so no need for the vette. i only have about $45000 into my car including the car purchase (it is #43 so i had to pay a dealer mark-up too on an 03 touring with navi) and the built motor and tt. if you shop around and find somethings used and can work on it yourself, you can make the Z a pretty mean contender.