I have been hearing all sort of chatter from my engin, always thought it was my valvetrain, then I realised it stopps as soon as I ease off the gas, even at higher rpm.  Detonation.... now it's the good stuff for her

Mine does too if it's any consolation.  

You could probably ease off on the timing advance but that kills power.  I think part of it is if you've done any modification to your engine.  Chances are,  the stock TBI is probably just barely getting enough fuel to the #1 and #4 cylinders.  Nothing out of the ordinary for any carb'd or TBI system, the further from the point where the fuel gets mixed in you are the more likely the fuel's going to start falling out of the mixture.

Adding anything more to stock and you're probably leaning out on #1 and #4.  There's also the distinct possibility in my case that my portmatching job isn't as good as it could be since I don't have a flowbench so I could have shot myself in the foot a little bit too.  Then again portmatching isn't quite on par with an actual port job, I just smoothed the transitions a bit which did actually require removing some metal especially on the intake side.  Had to JBweld and redrill the little air passages that supply the little brass tubes in the intake.  

Speaking of which, anyone know what the hell those actually do? I couldn't decide if it was for emissions or to help enhance swirl on the air/fuel mixture as it enters the cylinders which could help power slightly or maybe it does both so I figured it was better leaving em installed.

sounds like excessive carbon build-up too.

Octane is all about compression, and vice versa.  Each grade of onctane combusts best at a particular compression ratio.  The higher the compression, the higher the octane that is needed.  Believe it or not, the GV has a relatively low compression ratio, and Suzuki recommends against using higher that 87 octane or perfromance decreases.  I can attest to that being the case for me.

Now, if carbon build-up occurs in the motor, this reduces the volume of the combustion chamber, and in effect, raises compression.  Now, using regular gas, the motor will ping and knock, especially under accleration.

Engine cleaning actually works and is recommended, for example BG 44K Products (I prefer) or ProTech.  Products work miracles.  but it's a system usually sold only in shops and dealers.  Finding the right tech to do it is also important, so that they actually use the chemicals and cleaners and not take them home for their car (they are expensive).

you can get it on-line too.  Shop around.

Here's a couple sites I grabbe from Google:

http://www.storesonline.com/site/598452/page/45031

http://www.carfood.net/index.html

or go to BG themselves...

http://www.bgprod.com/

Octane is all about compression, and vice versa.  Each grade of onctane combusts best at a particular compression ratio.  The higher the compression, the higher the octane that is needed.  Believe it or not, the GV has a relatively low compression ratio, and Suzuki recommends against using higher that 87 octane or perfromance decreases.  I can attest to that being the case for me.

Yankee Tim is 100% right.

Mine has needed premium since I rebuilt it, if I run 87 it pings like hell, if I run 89 it still pings a lot.  If I run 91 octane it's fine.  Again though I also have a bigger cam, .030 overbore  pistons and .020 off the head which does increase the compression ratios static and dynamic (which is why I mentioned the cam).  I did some ballpark calculations and I should be running around 9.5:1 or so compression as it stands right now.  (not sure the exacts, it was a while back and I don't feel like digging all the info up such as piston dish volume and combustion chamber volume etc to figure it out again).

Belive me if I could get away with running the 87 octane I definitely would,  20 cents more a gallon adds up over time.  Buying premium because you think it's going to make a difference in performance by itself is silly, buying it cause ya gotta is a bit different.  I've got to run it on my VW too but that's a turbo so it's pretty much expected.  Then again that gets about 30MPG so I don't mind quite as much.

Next time your low on fuel, pull your spark plugs and open the gap up. If it calls for 030, go to 034-036. Then go to the station and try some 87. You might be surprised there is no more ping.

This is an interesting thread, I was useing 91
after the turbo install, but since adding the
intercooler, I can use 87 and have no ping
until I get to 4 PSI boost and the trans changes
gears, this is when the mixture gets a little lean
and I will get a little, but only until the mixture
gets back to normal, then it's fine again.

I'm sure when I get to full boost I'll need 91
but for now 87 RON Dino juice for the TurboZuki.

Mine has needed premium since I rebuilt it, if I run 87 it pings like hell, if I run 89 it still pings a lot.  If I run 91 octane it's fine.  Again though I also have a bigger cam, .030 overbore  pistons and .020 off the head which does increase the compression ratios static and dynamic (which is why I mentioned the cam).  I did some ballpark calculations and I should be running around 9.5:1 or so compression as it stands right now.  (not sure the exacts, it was a while back and I don't feel like digging all the info up such as piston dish volume and combustion chamber volume etc to figure it out again).

Belive me if I could get away with running the 87 octane I definitely would,  20 cents more a gallon adds up over time.  Buying premium because you think it's going to make a difference in performance by itself is silly, buying it cause ya gotta is a bit different.  I've got to run it on my VW too but that's a turbo so it's pretty much expected.  Then again that gets about 30MPG so I don't mind quite as much.

Did you happen to add flat top pistons (the 1298 pistons) at the same time?  these also raise the compression ratio.  If you did, your ratio might be higher than you calculated.

Nah they're definitely dished.  Wish they were forged though so I wouldn't have to get em for when I do the turbo, then again hopefullly I can just get a second engine for that.

I'll try the plug gap setting deal.  Probably should look at some new plug wires too, the ones on there don't exactly inspire confidence even though they're not all that old. They don't fit very well either for being "custom tailored."  NGK wires if anyone's wondering what they are to avoid buying a set.  

Honestly, I'm kinda tempted to cannibalize my MSD6A and Blaster2 coil out of my 240z though since it's not running and even when it is it won't be using the MSD again anyway. I've got the big MSD wires in there too, probably will just swipe them too since I'm going to use Magnecors when I get that running. It's not that there's anything wrong with the MSD (not sure it made any real difference but it definitely doesn't hurt either), but it's unnecessary with EFI and a wasted spark multi coil pack setup controlled by the EFI system.

I am kinda ticked because I called RRO soem time back who happens to sell the MSD for the trackers/kicks on their website and they didn't know beans about how to install it on one.  Probably no big deal since MSD has all their docs online as PDF's but I thought if they're selling it saying it works great they damn well ought to know how to install one and if any issues come up such as a tach adapter being required.