I bought a Vortech kit for my 03 Z and will be putting it on through this winter while my car is away. I plan on pulling the motor and tranny out so I can clean it all and do all the work I want easily. I plan on doing pistons and rods head studs etc.. so my question is what compression pistons should i get?

I'll be running 91 octane with a meth kit, I have utec with the wideband tuner, 600cc injectors, if totally necessary I will get a return fuel setup, I have a walbro pump And plan on getting the 2.87 pulley for the Vortech with GTM pulley.

I'm debating between 11:1 or 8.5:1....or I suppose whatever is available in between

Thanks for any help

 

I suppose I should add that I do realize that most people go lower compression for boost since with boost you're raising the effective CR of the motor anyway.. I'm just wanting to make as much power as possible with what I have.

 

I would just stick with the stock compression when you replace your pistons if you are keeping your Vortech. Is there something wrong with your motor now? The stock block should handle all the Vortech and the 2.87 can throw at it.

 

interesting. how long have you had your vortech on the car? what boosts are you running?

 

Since May 08' I have gone about 15,000 without any issues. I am running 11psi. You should also consider the TimRod pulley setup along with the GTM pulley. I was getting some belt squeal from my power steering pump pulley and the TimRod setup eliminated that and makes it so you don't have to run you belt super tight. The torque is what hurts the rods and since superchargers build boost with engine speed it allows us Vortech guys to safely go for more hp than with a turbo.

 

I have been running Vortech + 2.87 pulley since 2007 with no issues. If you do plan on building your motor for a supercharger stick with stock compression.

 

Good to know guys, thanks. I may run it stock block for this summer and buy a nice fuel setup instead and build it next winter. There is nothing wrong with the motor at all right now so if I don't have to pull it all apart all the better.

What kind of power are you guys making?

I also did plan on doing the timrod setup, I've been reading a lot about that. Just gotta take the pulley into work and machine it.

 

I made 366whp with the 3.33 pulley + bolt-ons, so I would wager I am somewhere around 400whp right now. I still run the Vortech kit the way it came right out of the box with the addition of 440cc injectors and of course re-tuning of the SS box. I also built a custom CAI for the blower but that was just for fun.

 

That's not too bad at all! I'm really hoping to get as close to 450 wheel as I can. I already have all the bolt on stuff and I have access to a dyno as much as I'd like so I have my fingers crossed .

 

if ur just running the vortech then dont build the motor it will hold up just fine with a good tune

 

building the motor for use with a vortech is pretty pointless.

 

ya unless you wanted to spray or go with a YSI blower, going to a built block wont gain ya much.

 

I think I'm going to have to disagree. I don't think my tune was bad at all, although it was not conservative in the least I'll agree to that. But 10K+ miles of vortech abuse and trying to get to 450whp...this happened:



I may be minority...but a lot of people will cry if this happened to them. For those people, I recommend a build.

 

This could be part of why your engine went kaboom.....


"Without any kind of tuning ( just ran my base map with the meth ON ), and it pulled like a MONSTER! I didn't do many runs because I didn't want to pop my motor due to the tuning but needless to say, boost went up from 12-13psi to 17psi!"

GT-ER

 

I ran with meth on that run and a/f ratio and timing were pretty conservative. Keep in mind I said BASE MAP, I had 5 maps in total to play with and the base was the most conservative. It didn't blow up at that moment...it blew later with less timing...go figure...lol.

Again, I'm not saying that my car set an example when it came to conservative tuning as I was constantly pushing it, it was not conservative in the very least...but I wasn't all that aggressive with it imo. I was far more aggressive with my other Turbo cars and they never failed.

As a matter of fact...the G has been the only catastrophic failure I have ever had in the many turbo cars I've had. I am also not the ONLY Vortech car to pop...I've read of quite a few ( although we are still the minority ).

 

^What fuel system/injectors were you running with 17psi?

When building my motor with 10.0:1 compression, I figured I was going to stick with a SC plus a 100 shot but my plan changed after assembling the motor. I ended up selling the SC and n2o and buying TT. If I can max out these turbos with this compression and pump fuel I have reached my goal.

Make sure you get the compression you wont regret later.

 

there was no regard for the life of the motor in that example. that cannot be used to represent a reason to build a vortech motor. That owner had at least a dozen "problem" threads with nothing done to fix those "problems" just continuous beating on the car.

Noone has broken a crankshaft either if that means anything.... take that opinion with a grain of salt.

 

This, GT-ER's motor likely had other issues and 17psi certainly wasnt helping the situation. 450whp is possible but you will likely need cams and lately people have been seeing really nice gains from upgrading the intercooler.

 

While I DID have a quite a few problem threads, who says I did nothing to fix them?

I had spark blow out which I fixed. Low power in the beginning which I figured out what it was ( for the most part ). I eventually had the faint knocking, but I simply couldn't do anything about it without tearing down the motor, so I ignored it. My engine blew, but as I said earlier I'm not the first to blow an engine with a Vortech. This is also the first engine I blow EVER ( I've owned a few turbo cars and have built others ). I'm not completely clueless. I'm just kinda new to the VQ.

As for the broken crank shaft...I have no idea how I did that...lol.

All I saying is that anyone willing to go into the 400whp range on a stock engine should be ready for anything.

 

Walbro intank, AAM Stage 1 FRS, 550cc injectors that were later upgraded to 750cc injectors cause I was hitting 100% DC constantly.