toykilla

iTrader: (1)

I am new to engine mods/turbos etc...
Would it be better to go with a turbo "kit" such as the Greddy one coming out later this year, or have an experienced engine shop build a custom turbo setup. Please give me pros/cons of each if any.

I have talked with a recommended shop already and they already have one z lined up for a custom kit at the end of summer and would like me to be a second "prototype" z. The first guy is going for 450-500rwhp, and they quoted him $10-13k.
I would like to start at around 350rwhp and upgrade it over time. They will strive to meet my specifications, so i would guess maybe 350rwhp would be in the $6-9k range. They said over 400rwhp, the engine and trans must be strengthened, so the price goes up.

Would getting a kit limit my car's potential later on, and/or would i have to replace some of the major components in the kit to increase power?

Please help !

Zaphod 350z

My OPINION...

Having a competent experienced shop build you a set up would no doubt yield more horsepower than a Greddy kit. The Greddy kit is designed to be a bolt on application for ANY Z. Your shop will make you a custom set up that can be tuned to your car. They would no doubt change your fuel system (DFI) and motor components.

However, it will be considerably more expensive than the "over the counter" kits. Main reason is greddy will be making many kits so their materials cost will be lower and they can cash in on their design and fabrication costs.

zland

Greddy will have a lot of tubos on the street soon. If they are Engineered poorly, they will have a lot of Liability thus my bet is they will be more conservative thus less hp.

toykilla

iTrader: (1)

Greddy is claiming 345rwhp.. .this is right about what I would like to start at. BUT, I want the ability to go higher later down the road with minimal rework. (just add more parts/boost/whatever).

What is the limiting factor in a bolt on kit such as with Greddy?? Turbo size? ECU?? Fuel system??

If i have to replace most of the kit components to get more power, forget it. I will go with a custom built system. However, if I can just add more components and up the boost (unclear as to how this happens???) later that seems like a good way to go.

ACOSTARACING

Well, we have done custom turbo kits for over 15 years, for many cars. I think what you should think about is

1. How much power are you wishing for (now or Future)
2. If you only want low power, then go with a Greddy kit.

however if you are looking for big horse power then go with a custom.

failsafe

3. How much are you willing to spend?

SpyVO

Well those things all contribute and it's all those things added together that make it tough. Turbo size is the easiest to deal with. You crunch some numbers with a goal in mind and you'll figure out quite easily what size you need.

I'd expect the computer to be a big task to deal with when it comes to adding a turbo setup. The Z ECU has aggressive timing that is optimized to extract the most power from premium fuel. So for a turbo, that pretty much translates into a need to back off the computer in terms of timing. From what I've read on here, this isn't as easy on a Z as it is with some cars. I think this will be THE most difficult aspect of adding a turbo to a Z, simply because of emission compliance and the complexity of today's engine management systems.

I do not know what the capacity is of the stock fuel system. On some cars you can just upgrade the pump, get an adjustable regulator and go at it. I don't know if the Z will be that easy.

The first thing you need to do before writing ANY checks or spinning ANY wrenches is a ton of research. Solve these problems before diving into the project. Look at other cars that have setups like what you want. Ask yourself, "Could I do that to my car?" What you are looking to do HAS been done before, many times. You just have to make it work for your car.

Here's how I'd go about doing it. First, I'd find out what cars the VQ35 came in. FWD or not, check out ALL of them. Could a FWD engine be used in the Z? Sometimes you can do that, other times it doesn't work. Why bother with this? Becuase if you buy an engine to build up, you have the stock one as a backup for relase, or when things go wrong. Find out what parts interchange. You may be surprised at what you find out. Wierd stuff can swap sometimes. Just keep that in mind. OK, so we have the shortblock built with good guts, and the orignal engine in safe keeping. Second, I'd consider what needs to be changed to make the turbo work. You said the ECU, right? Well I think the Z ECU is great for what it does, but for a forced induction setup, it's just about worthless without modifications. So lets pull that out and put it with the original engine. What WILL work. Well, let's see. There's the stuff from a Twin Turbo 300ZX, right? Why not that? Or a last gen Supra. Or even a Buick Grand National/Turbo Regal. Sneer at the American technology if that's your thing, but there's no denying those cars. And parts for those would probably be the least expensive route. So now you got your motor (with turbo) and computer stuff. It should run now, and will run hard if you feed it right. This is where the fuel system comes in. Start by checking out the fuel system of whatever car you got the ECU from. What upgrades do they do to that system? That would be a good place to start.

So it may seem a bit ghetto to do parts swapping like that, but I'll bet you anything you could get a car with a setup like that to run just as hard as whatever those people will be spending 13k on.

That's my take on it.

toykilla

iTrader: (1)

Thanks for the info, I will be doing extensive research over the next few months to see what is the best route for me to take. The car is only a few weeks old, I figure there is plenty of time to build it up.

SpyVO

Well heck, at least wait till the warranty is up!

toykilla

iTrader: (1)

but i wanna go fast now

Importlife.com

Start with a Nitrous application first.