I need to find out exactly what and why our cars need to have the timing retarded after 15 psi. I plan on running more than 15 psi prety soon so give me some info about it.

...like are you flowing a stock head, running shitty gas, high compression and even a hotter turbo. Our cars are still pretty responsive at the 8.8:1 compression. As reported many people have been able to break loose at 90mph in 4th. Dino posted ealier how he runs 15 and no retard. That and his turbo comes into it's effieciency at about that time. I'm at about stock compression and I run a lot of retard all the time for more than 15 pounds compensation. With more compression and boost you can run a lot of power all the time without much loss do to the climate and sea level at the risk of running your car at the edge - detonation. With running more boost you can run almost the same amount of power with less compression but you encounter different symptoms such as power loss instead of timing, and more lag. So it depends on what you want to do, most people prefer more lbs and lower CR route. Less compression+boost is easier to tune to than more compression+boost-timing. Especially if you are new to the tuning thing or don't have some ignition amp with programmable timing retard like the Crane or DIS.

I in the process os getting the 8:6 compression pistons installed. I plan on running 15 psi for a while. I think I can run 15 without retarding the timing. I talk to a lot of 4g63 guys and they always talk about their timing being advanced like 22-26 degrees. It might be a dumb question but why do they talk about advancing their timing and we talk about retarding our timing?

The more timing you run, the more power you make. When we are talking about retarding timing, it's usually .5-1 degree per lb of boost above 15 psi. This is to stave off detonation, the same way the knock sensor does on the 4g63. You still may end up with 20+ degrees of timing, depending on your state of tune. Under 15 psi, you can run as much timing as the ecu will allow.

So since we do not have a knock sensor we have to manualy do it with the DIS. Ok, now I understand it a little more.

Dave, we do have a stock knock sensor in our cars also... the reason people get the dis2 or crane etc is to retard timing a bit more for people who run over 12psi or if you run your car over 4,000rpm to redline etc alot( people who race alot ) ...this is where detox gets us most of the time.. what injecs did u decide to get?


Michael 99gs
Mods:
Hrc Stage 2
S-FMU
315cc injectors
Crane HI-6DI2
Greddy Type S Bov
VC-2
Road Race Catch Can
Greddy Profec B & Switch
Apexi WS Catback
Super Afc
Autometer Boost,
Egt,Tranny Temp Gauge & Cooler
Air/Fuel Light & Digital
Tokico Adjust Struts
Eibach Pro Kit Springs
Front & Rear Upper Bar
CarCraft Interior
Sound System= Bring it On

Well I havent bought the injectors yet. I think I want to get the ford ones that are 42lbs or 441cc if I can share the cost with someone. If someone wants to go half with me let me know because if not I am going to get the 415cc from hahn.

I run 15 all day w/ out retard,and I ran 18 w/ out it for a good 2 months.I turned the boost down cause of a new head.It didn't seem to hurt anything.Compression and plugs looked fine.

just because it ran fine/ compression is good does not mean detox is not happening... there has to be a little bit of detox happening... ill leave the rest to the pros...

Michael 99gs
Mods:
Hrc Stage 2
S-FMU
315cc injectors
Crane HI-6DI2
Greddy Type S Bov
VC-2
Road Race Catch Can
Greddy Profec B & Switch
Apexi WS Catback
Super Afc
Autometer Boost,
Egt,Tranny Temp Gauge & Cooler
Air/Fuel Light & Digital
Tokico Adjust Struts
Eibach Pro Kit Springs
Front & Rear Upper Bar
CarCraft Interior
Sound System= Bring it On

...seriously unless you're running some sort of race gas or have 8.5:1 compression pistons(if that) you were hitting detonation...period