Pre-Turbo Modifications

[Weirdo_Joe]

Ok, my plan was to get headers for x-mas, but thanks to this forum, I've learned that if I plan to put on a turbo setup eventually (which I do! ; ) that I don't want to DO that. I'm obviously new to this, but I'm learning, and eager to do more! While saving up for the turbo, what other modifications can I do in the meantime? I am interested in anything, but am currently thinking of a couple things...
1. Cam-shaft pulleys. Has anybody used these? I am curious what kind of performance gains may be attained, and if they will benefit/conflict a turbo setup... just from what I've read, I am guessing the underdrive pulley I have and these would all be helpful and usable...
2. Forged Pistons. Good power gains, right? Would this be a good idea to do on the way to turbo?

Basically, any modifications that could be done before (and in conjunction with) turbo, or anything that would be a good idea to do in PREPARATION for turbo, I'm open to, and appreciate any information!

[Daox]

Adjustable cam timing pulleys would be a nice addition for almost any engine. They essentially do the same thing that VVT does (shifts the powerband), but you can only set it to one rpm at a time versus how VVT constantly varies the cam timing. I'm not aware of any place you can buy these for the Aveo though.

Forged pistons are not necessary IMO. They don't really provide any gains per-say. They are simply stronger than normal pistons. This allows them to hold up to higher boost pressure essentially. However, when you get new pistons you can also change compression ratio which can be used to run more boost, or have more off-boost power. So, the bottom line is unless you are planning on really building up the engine to handle a ton of power/boost, I'd just stick with the stock pistons. I think you'll get plenty of fun out of them.

The biggest thing I'd be shopping for right now is probably a programmable ecu. There are many options out there from piggybacks to standalone systems. You'll need to choose one and understand how it works to tune it (or pay someone to tune it).

I'd also highly suggest Maximum Boost by Corky Bell. It'll go through all of the things you'll need and teach you what you need to learn to put a turbocharger on a car. Seeing as this will be a custom one off setup, it'll save you a lot of time and money by knowing better what you're doing. I have his book on supercharging and it was invaluable when I was doing work on my car.

[petrified.rabbit]

to run higher boost reliably, the compression ratio needs brought down, pistons or a head spacer are the typical way of doing this. Pistons mean complete engine tear down.

in all honestly, you should not go turbo, or anything just because. You should start with what hp range you want, what drivability you want, reliability, cost etc, and go from there.

[Weirdo_Joe]

Man, thanks for all the pointers and suggested reading, Daox! I do have a LOT of time, and quite a bit of money to spend on this car... and I am already having a TON of fun playing with and tuning it! Rabbit, if you're suggesting I give up tuning the Aveo, and go out and buy a car that has what I want, I've thought about it, but that wouldn't be NEARLY as much fun. (Maybe an engine swap ; ) I really enjoy watching my 0-60 times creep up... I have seen cam pulleys from xiaogary; dunno if they are adjustable, but I know they are performance geared... I'd LOVE to talk to somebody who's used them! As far as the ecu, I have looked for an on board tuning "chip" or computer... most people that make'em don't make'em for Aveo, but I recently found on this forum the Apexi Neo... ppl have used it on the Aveo, and say it helps a bit... reviews other places say it's even better on turbo systems. Ya'll know of anything better (or anything else AT ALL) that's compatible with a '08 Aveo? And yeah... it wasn't just forged pistons, but pistons with "overbore" ... Is that what changes the compression ratio? I do wanna either beef up the engine enough to handle mid-level boost (at least) or do a swap... thanks again! I'll check out that book! Have a great weekend, anybody reading this...

[Hatchbackhilbilly]

over bore means that while the engine is apart, a machinist will use a milling machine to open up the size of your cylinder bores, thus increasing the size of piston necessary to fill said bore efficiently. which increases your engines displacement. and anybody in racing will tell you, there's no replacement for displacement. this can also be achieved by the use of what's called stroker crankshafts, which utilize longer throws to increase the distance the piston travels, however, most modern day engine blocks require being relieved in order to use a stroker kit, and even at that, the engine will never rev up as quickly (not some thing you want if your going to start worrying about turbo lag). IMO, the best displacement gain with the e-tech II 1.6l would be .060 overbore pistons, its not too much to worry about sleeving the engine, but its quite a bump. all of that said, i have yet to find a stroker crank for th 1.6L, or even the 1.5L found in other models around the world. but believe me, i'm looking... any other question please feel free to ask.

[petrified.rabbit]

the 1.8 in the cruze is an overbored version of our engine, the 1.6 is already stroked from the original 1.4 design.

the older engine has the same characteristics with other engines.

[petrified.rabbit]

Rabbit, if you're suggesting I give up tuning the Aveo, and go out and buy a car that has what I want, I've thought about it, but that wouldn't be NEARLY as much fun. (Maybe an engine swap ; )

i/m not saying to buy a different car, i am telling you too look for your desired outcome to decide ho to build your car.

if you want your aveo to have 150 hp, its going to be completely different than 200hp. If you want to just slap on a turbo and standalone, you might not have the reliability, you need to build it as a whole.

[Weirdo_Joe]

Nice, nice! Thanks Hatchbackhilbilly! That's great info! I'm taking notes; not ONLY trying to improve performance, but learn along the way! I think I've heard the same figure before... .060 overbore. That's what I'm thinking of... Do you know how that modification alone changed your times? (0-60, 1/4 mi) I'm trying to see how low I can go before adding turbo! I like your signature, btw! Backing up a bit; rabbit, you mentioned a "head spacer"... that achieves better compression ratio without a total engine teardown? I can't say "thanks" enough... rabbit, you helped me through the CAI install, Daox, the pulley, and Hatchback, you just came outta nowhere more than willing to help! Any of you 3 want, I'll send you a free t-shirt (either the drugsT or the black CBM... I got PLENTY of those!) just an offer, a small token of thanks... you guys have helped a lot, and caught me on a good day! Private msg me if you're interested! To see'em, just check out my signature.

[Hatchbackhilbilly]

sweet dude happy to share the info... and rabbit, where do you find all this info i've been searching for?

[Nemasys]

Quickly off my head as i dont have much time at the moment, i would recomment a full exhaust from front to back, thats a must if you want a turbo.

You can stiffen your engine mounts as well, the engine will dance alot with the added power trust me.

Good suspension to put the power down with good rubber.