Trypt

I decided that I cannot sell my car, every time I come close and I get an offer, I make some lame excuse, so I finally admitted to myself that I just cannot part with my baby.

So, its time for mods, but I need some serious info. Yes, I have searched the forums, and everything I know I learned by reading thirdgen forums, but I couldn't find the answers to the following!

Basically, the goal is to turbocharge the car in the future. However, I want to mod it in the meantime. My concern is to not waste money, so I need to know what mods are NOT compatible with turbo in the future, so that I don't spend money now just to have to remove them later.

In a nutshell, all mods I make to my GTA have to be compatible with a future turbo, and I am looking for suggestions as to how to proceed.

Also, after I am done with these mods, I will then strenghten the parts that need it before turbo.

I am leaning towards Holley StealthRam for the intake, is this a good choice considering turbo in the future? Or should I just stay with TPI (modded) because turbo will take care of the top-end later anyway, and TPI gives more torque then other intakes, meaning that I could actually end up with a faster car staying with a modded TPI rather then a HSR or miniram/superram??? (my philosophy here is that the huge low end torque of the TPI may become a bonus after a turbo is added, and the lack of mid-high end power irrelevant, but I could be wrong)

Is a new 52/58mm TB a must, or is the stock unit ok after a good porting? How about heads? Must be new or ported ok?

Naturally I will do exhaust, but i'll post an inquiry in that section, but I have some trouble understanding headers and turbo! I figure I have to forget about headers due to my future turbo plan right? Or perhaps put on turbo-headers now even without a turbo (what will that do?) If someone could explain headers and turbo/super, that would be great, cuz I have no clue. I thought that you can't use headers with a turbo, but then I hear things like "turbo-headers".

Finally, just FYI, my goal is 300+rwhp before turbo, and more after (like I said, I will strenghten the parts that need it by then, but that will be in my future posts).

How about cam? Is is possible to upgrade to a cam which will be good before the turbo and after? If so, any ideas?

Does any of the above make any sense whatsoever? Put me in my place, but don't poke, like I said, everything I know about any of this is what I've learned from you guys.


Any ideas are welcome, even if completely new, I am not 100% set that Iam going this way exactly, I could change my mind (eg. I would consider supercharging vs. turbo, or go with neither and rather use the 2-3k to build up the motor further?!), but the only thing that is for sure is that I will not do an engine swap and no NOS.


Oh btw, I want this to be a daily driver and when driven normally (highway mostly), good fuel economy. This will not be a track car (as evidenced by my goal of 300-400rwhp). I am shooting for 13s before the blower option, and low 12s, high 11s after.

92zcamaroperson

iTrader: (1)

i can help you on a few things. Do some searches on turbo setups. You have two options. They can be under the hood or you can do a rear mount setup. You find lots of info on the under hood setups which use turbo headers that the turbo itself bolts to but from what i can tell they are a little more difficult for a dd because its hard to fit everything in there and not melt stuff and keep a/c. I like the idea of a rear mount setup myself but I cant find a lot of pictures and information on it. They mount in the back of the car where your muffler is and then the pressurized air is piped back up to the engine. Either way if a turbo setup is a ways off in your plans you might as well pick up a set of cheap used headers to stick on in the mean time. Whats your goal after the turbo setup? That is going to determine your cam. You could get an off the shelf cam to work just fine for you but if you are going to really get into it and boost high id get a custom ground one to squeeze every ounce of power out of it. At that point you would definetly need a tune as well. If this is a dd and you want some efficiency with the power then turbo is the way to go. If you just want power everywhere supercharging is the way to go. Its a little easier to install and configure. If you dont mind doing some research on your own to find the best comination heads and cam swap are the way to go. But you have to make sure you match everything together and double check yourself. More is not always better. But making a n/a tpi motor efficient isnt easy and wont yield the same gains as a power adder like a turbo or supercharger....Hope this helps you out. You are on the same path I am. I have attempted to sell my 92z a couple times but I can never quite do it and the idea of a turbo v-8 makes me happy on the inside

Trypt

Thanx for the info. So let me be more specific and stick to the topics you discussed.

1. I like the idea of rear-mount. If done properly, it doesn't interfere with any components, and does it lower ground clearance? Also, how would an intercooler work, where would it be installed? Is there a possibility of twin turbo at all using this setup?

2. About my intake, I thought I would get some input here but nobody responded.

Especially with a rear-mount turbo, which would probably be a bigger single turbo setup with definite lag, it makes my decision about the intake harder.

Originally I wanted to go with Stealthram or perhaps superram, but all these intakes rob low-end torque and move the curve towards higher RPM.

Now, I figure, with a big turbo, wouldn't it be better (in pretty much every respect, including price AND power) to stay with TPI, and just make it the best it can be (long tube runners, new TB, ported plenum etc...)?

Theoretically, I would end up with a monster torque motor which has absolutely no need of turbo at the low end, but one which would lose power quickly above 4000rpm, but I figure this is exactly when the turbo would hit its peak (it would contribute before that of course). With a good cam, I am thinking a TPI intake would be the best with a turbo, but I could be wrong, that is why I am asking.

3. Another option would be to get the Stealthram and have a nice steady torque curve with lots of area under the curve, but add a supercharger instead of turbo? Before visiting thirdgen.org, in fact, I never even considered turbo, and in fact, I have never really driven a turbo car, and I love superchargers (my 2nd car was a Cougar XR7 1990, with a 3.8L supercharged engine, amazing!), but thirdgen.org convinced me of turbo and pretty much made me fall in love with the idea of a turboed V8!

92zcamaroperson

iTrader: (1)

With the right turbo lag will be minimal. Torque is great but you wont be able to use it on the street with no traction. So you can have lots of power but you arent going to go anywhere. Aside from that on a stock motor you not going to run a big turbo anyways because a small turbo will max out the engine. You are only going to be able to run around 6-8 pounds of boost if you have a 350. So the small turbo will cause minimal lag at most. How many miles are on your motor?

Your question on the intake is answerable by how much you want to spend. I would put my power higher because you will be able to use it on the street. even with power higher in the band you can make your car have instant go with a higher stall.

Anyway you go the v-8 will have plenty of torque to make you happy and your smile will only get larger when the turbo kicks in.

with a turbo its easier to be efficient on gas as opposed to going with a super charger. If you want a torque motor and that it then keep the tpi setup with some long runners, get a nice cam to match and get a supercharger. If you really want a torquey motor stroke the engine to a 383. You will never hook with street tires again.

Trypt

Actually, I am through being beaten by S2000s on the highway, and I don't care for spinning tires too much. The only reason I deviated from my original plan to change the entire intake to a HSR is because I figured I may save money by modding the TPI, and not suffer top end loss due to the addition of turbo. But since turbo is at least 2 years in the future, I think HSR is really the way to go for instant noticable difference in feel (and some extra power too!).

Really, I only brought up turbo in this to let you guys know that the ultimate plan in the future, after the mods are done, is to add the turbo.

The steps are a) engine mods to add power, b) engine strength (forged pistons etc.), suspension stiffness and wheels/tires and c) turbo.

So, as you can see, I want to make more power, as I said about 300-350rwhp is plenty, then I will strenghten the engine so that the turbo will not destroy it.

The plan is to first upgrade the exhaust (Borla catback is the plan right now), then intake (HSR is looking like the winner), but then I am not sure how to proceed. Cam already? or start on internals like heads right away?

ALLTEC-Z

If 300-350rwhp is all your after, you don't need to turbocharge it. that power can be acheived without all the headacks, weight and loss in fuel economy.

Abubaca

iTrader: (3)

Like you said, exhaust first. Pretty much a necessity.

Then, I say torque converter. Arguably the best mod I've done as far as seat of the pants feel. Choose the stall speed based of course on whatever intake you're gonna settle with. I've got a 2500 with a stock TPI and ZZ4 cam. LOVE it!

....then you can get into cam, heads, intake etc. etc. but these all really depend on future goals etc. etc. I agree that for 350 HP, I wouldn't mess with a turbo at all. WAY too much cost and headaches for only 350 HP. You can get that HP EASY EASY EASY without a power adder.

Trypt

Thanx for the replies from both of you, but you did miss the goal of my build.

Yes, 300-350rwhp is my goal, but this is before the turbo. Guys, you missed the whole point of my post! I want to know what the best mods for my L98 are which will give me 300-350rwhp but also at the same time work very well once I install the turbo. I want to avoid getting upgrades which will have a minimal effect, or worse, must be removed when I install the turbo.

Once the turbo is on, I will start with low pressure for a gain of perhaps 50rwhp, then begin really strenghtening the engine and increase boost as I go.

So, exhaust is the obvious first step, at least from the cats back, since headers are not compatible with my stated goal (turbo headers will be added with the turbo, at least until someone tells me otherwise, I am confused on this). Intake seems like a good 2nd step, but then I get a bit stuck. How long into the build can I wait for working on internals? Do heads really have to be done early on? How about cam?

Drac0nic

What are your turbocharged power goals, and is race gas out of the question? I think that will determine how radical you need to be with the engine. Head, intake and cam choices will be determined by this stuff. TBH, you may not have enough of one of these to make the power you want N/A, but your turbo goals would be easily accomplished.

Some 72/76cc aluminum heads would drop both the static compression and dynamic compression due to the aluminum which would lose some power N/A, but the flow would help depending on the heads and when in boost it would probably be safer with the pistons you have. You can get away with running a stock short block, at the same time I don't know if I would want to chance a set of aftermarket heads on one.

How's your powertrain? Trans, axle etc. are healthy and fairly low milage and/or well built? Even if your intention is roll racing, keep in mind that power is hard on these components.

What about your fuel system? If you're wanting about 500fwhp something like a 255 Walbro will do, much past that you really need to be looking into a good fuel pump, an aftermarket regulator and running a -8 feed and a -6 return or using your old feed line. New injectors will basicly be a requirement regardless, some Ford Motor Sports 42s will work and are fairly cheaply found, if you buy new get the Siemens Deka 60lb/hr ones though.

What about engine management? I'd be thinking at least the 1227749 ECU set up with Code 59, if not a Megasquirt or other aftermarket system.

You'll need new headers for the turbo system, or to modify a set you already have. There are a few different ways to go with this, even though L98 vette headers flipped upside down have been used well in a twins setup with some modification.

Trypt

Drac0nic, after reading your post, I may have to rethink this. Perhaps I am thinking too big with parts but too small with my goal.

I should have stated this, but I don't want pure racer or even a supercar killer.

Most important things are still drivability and reliability. I want to be able to drive in town or on the highway and enjoy it, and also not have to stop at the gas station every 100 miles (I expect to lose some fuel economy, but it still needs to be reasonable!). I know things break but I don't want a car that needs tuning and replaced parts after every run down the strip!

I was shooting for 300-350 wheel hp before turbo, and thinking perhaps to add another 150 with the turbo after strengtening the engine, but this seems excessive now. Perhaps knowing this it would be better to state my goal in speed terms? 12s would be absolutely beautiful if it can be done without sacrificing all the things i said were important to me.

So, am I wasting time by planning on all these upgrades then adding a turbo as far as my goal goes? Should I instead just focus on either fully N/A, or power-adder but less bolt-ons/upgrades?

Summary: After all is done, I want a car that is fun to drive, can be an every day driver if chosen to be, can run 12s in the quarter mile, and doesn't run out of breath when pushed on the highway (the L98 stock makes a lot of noise but really doesn't pull much when the pedal is floored at 70mph)

Abubaca

iTrader: (3)

Well, here's the thing. Ya gotta read between the lines, but there's a big difference between a motor with a turbo and a turbo motor. Know what I mean?

Take superchargers or nitrous for example. You can run either on a bone stock L98 and get some really good power. ...-BUT, if you had to plan a motor build up and you plan on using any form of power adder, you sure as heck aren't gonna choose a bone stock L98!!!

I think I understand kinda where you're going, but ultimately it's gonna be you who has to make the call and spend the money. Here's MY logic towards MY future plans: First of all, I'm not gonna throw out any numbers, because everything is debatable and there's no need to split hairs about what I CAN and CAN NOT do with my plans. What I DO know, is that my goals AND my wallet can't handle a fully built motor capable of handling high power, power adders. This means no fully forged internals capable of handling a big ole turbo. I DO know that a stock/mild L98 with a turbo/SC/N20 is do-able, and in the ballpark as far as my goals. I also know that a naturally aspirated motor with the parts I want CAN reach similar goals with similar cost.

Regardless, whatever goal you ultimately choose, I'm not sure you can really buy today, and plan for tomorrow. Not saying that everything you buy would be worthless, but as is mentioned over and over and over, the entire system needs to work together. I don't think you can REALLY build a worthwhile system today, and have it be what you'll need when the time for a turbo comes along. I think you need to pick either "today" or "tomorrow" and build accordingly.

Drac0nic

12s with boost would be pretty easy, fuel system upgrades, ECU upgrades and probably a damn near stock if not stock motor. Perhaps pull the TPI intake, port it some then add a cam on top of that, or some different aftermarket heads to drop the comrpession down, or lightly worked stockers. If you pull the motor apart all the way at the very least widen the ring gaps so they don't butt. If you're building a second motor up at the same time, I probably wouldn't even go that far tbh.

Check this thread out, coupla guys running great times on virtually stock engines. https://www.thirdgen.org/forums/powe...e-running.html There are guys out there making quite a bit of power very easily on stock 5.0 Ford motors too, it's just a matter of setting it up right. That's why I said what I did with 300-350 to the wheels, if you had the motor properly set up to make 350hp N/A then threw boost on top of that there's little doubt in my mind you'd see a lot more power than you have in mind. Sign up for www.theturboforums.com and check the dyno results section/search for stock engines, I think you'd be surprised at some of the #s they get on bone stock motors or super close to it.