Increase base timing?

[delta448]

First off, I searched for about an hour and a half for anything on this site about timing adjustments, using both regular and advanced searches. All I could find was stuff about timing adjustments made with DSMLink or other EPROM ECU only equipment. I don't have any logging or fuel adjustment equipment. Currently, I am running a S16G @ 14.5psi, stock injectors and the stock fuel pump so I haven't needed much electronics yet.

Now my question: I have heard that significant power can be made by simply adjusting base timing on a 2G. Supposedly, factory settings were really conservative for reliability in hot weather. Is this true? Since the hottest day of the year here is roughly 97-100* F, I'm thinking I can still be safe and lose some of the factory caution. How much timing advance would be safe on my setup? -Or would it be safe at all?

I don't plan to go above 16psi anytime too soon. If I ever do, I would certainly reset timing to factory settings before boosting higher to get an accurate starting point for fuel management adjustments. I know that base timing is supposed to be set at 5* BTDC with a timing light. Would I be able to use a timing light and adjust base timing say to 7* to 10* BTDC safely? Or how much advance would be okay?

Anybody with experience adjusting base timing, please give an opinion.

 

[exiletalon]

First off, I searched for about an hour and a half for anything on this site about timing adjustments, using both regular and advanced searches. All I could find was stuff about timing adjustments made with DSMLink or other EPROM ECU only equipment. I don't have any logging or fuel adjustment equipment. Currently, I am running a S16G @ 14.5psi, stock injectors and the stock fuel pump so I haven't needed much electronics yet.

Now my question: I have heard that significant power can be made by simply adjusting base timing on a 2G. Supposedly, factory settings were really conservative for reliability in hot weather. Is this true? Since the hottest day of the year here is roughly 97-100* F, I'm thinking I can still be safe and lose some of the factory caution. How much timing advance would be safe on my setup? -Or would it be safe at all?

I don't plan to go above 16psi anytime too soon. If I ever do, I would certainly reset timing to factory settings before boosting higher to get an accurate starting point for fuel management adjustments. I know that base timing is supposed to be set at 5* BTDC with a timing light. Would I be able to use a timing light and adjust base timing say to 7* to 10* BTDC safely? Or how much advance would be okay?

Anybody with experience adjusting base timing, please give an opinion.

i believe that they gave caution not only for heat and weather precautinos- but also engine longetivity, to maintain a more durable situtation for them ( IE: warranty)- i believe that there is some margin of space- but consider your mileage - if its high, knock may present itself, although i dont think 5-6 timing should bother too much, although your are putting stress on your engine, its like turning up the boost, and running the same gas- it may work, but chances are its working really hard to survive the stress

 

[exiletalon]

i also know from experience that 97-99 2G's have a much weaker timing, i do not know of a cure, but it is totally absent in 1G's, and very minor in 95-96
i would be careful- do a lot of research before you attempt anything

 

[delta448]

The TSi has 80k on it right now. I run 93 octane only. I drive the car fairly hard sometimes, but always make sure its maintained well (fluids, belts, hoses, etc). Granted, I don't have any way of monitoring knock right now, so I was just wondering if a couple degrees advance would be problematic?

 

[exiletalon]

The TSi has 80k on it right now. I run 93 octane only. I drive the car fairly hard sometimes, but always make sure its maintained well (fluids, belts, hoses, etc). Granted, I don't have any way of monitoring knock right now, so I was just wondering if a couple degrees advance would be problematic?

i would wait to any advanced modification like that until you know the complete and udder condition of your car and have consistent proof to run by- if something like that goes too far- your pistons will turn to goo, and run out your exhaust

if its in great condition- then i think a 10-12 degree may be fit- maybe an AVCR or timing computer would me an investment to look into- there is definitaly some power on tap there - but it is a tricky thing to work

 

[jepherz]

If you watch your EGT's and your knock VERY CAREFULLY, there's no reason why you can't turn up the timing. This will give you a lot of power gains.

 

[exiletalon]

i would wait to any advanced modification like that until you know the complete and udder condition of your car and have consistent proof to run by- if something like that goes too far- your pistons will turn to goo, and run out your exhaust

if its in great condition- then i think a 10-12 degree may be fit- maybe an AVCR or timing computer would me an investment to look into- there is definitaly some power on tap there - but it is a tricky thing to work

if you find this helpful - please add a comment and/or reputation point please

 

[andymoraitis]

There is NO way to adjust the base timing on the 2G's using the CAS like you can on the 1G cars. While it's true that more timing advance can equal more power, this has to be done in the presence of minimal knock, otherwise timing will be pulled as a result and you're back to square one. Considering that you're on the stock fuel system, 14.5-15psi is about the maximum you should run.

Once you step up to larger injectors and a larger fuel pump (a 190 with 550's will be fine), you can lean the car out sufficiently while adding more boost to create more power. An AFC will give you additional timing advance as a result of subtracting airflow, but it's not the best solution since there will always be a compromise between leaning out and adding boost while keeping timing in check.

Other options include an EPROM ECU with DSM Link, or an EPROM ECU with a Keydiver Stage III chip that has custom air/fuel and timing maps built in. This is what I run and prefer, but do your research once you upgrade the fuel system and see what works best for you and your budget. On 93 pump gas, it's best to shoot for air/fuel ratios of 11-11.5:1 with 18-19 degrees of timing advance near maximum RPM. Also understand that in the presence of a lean A/F ratio and adequate timing, more boost will make more power than more timing (on pump gas). When tuning for race gas, more timing and higher boost levels can be used since knock threshold rises with octane.

Hope that helps,

Andy

 

[Ultimatedsm]

There is a certain limit where timing advance makes power, if you go overboard you will make your car run like or possibly blow your engine. If you are adjusting base-timing and go overboard, your car probably will start to run rough all of a sudden. Your car isn't that modified yet and don't really need to mess around with timing yet. Your running a s16g at 14.5psi on the stock fuel system. Why don't you get a walbro 190lph fuel pump, SAFC and 550cc injectors or larger? Stock fuel system can't flow nothing, you need to upgrade the supporting mods to support that turbo a.s.a.p.

 

[ericbev]

Usually pulling timing and adding boost gives better results than adding timing and lowering boost.

 

[andymoraitis]

I agree with that to a point. Running below certain timing levels will generate tremendous amounts of heat in the motor. Try a pull at 19 degrees and then try one at 23 and see how much lower the 23 advance EGT readings are in the absence of knock. The key is to run adequate timing in the neighborhood of 18-19 degrees when dealing with pump gas. The guys running large turbos, high boost and low timing (8-12 degrees) are doing so on built motors. Trying this on a stock block will result in meltdown faster than you can blink.

Andy

 

[dave99gst]

You can use a 1g CAS to advance your timing on a 2g.
My car has always like a few extra degrees. I get a bit more power
with lower EGT's. but yeah, be VERY carefull.
http://roadraceengineering.com/1gcasin2g.htm

 

[ericbev]

I agree with that to a point. Running below certain timing levels will generate tremendous amounts of heat in the motor. Try a pull at 19 degrees and then try one at 23 and see how much lower the 23 advance EGT readings are in the absence of knock. The key is to run adequate timing in the neighborhood of 18-19 degrees when dealing with pump gas. The guys running large turbos, high boost and low timing (8-12 degrees) are doing so on built motors. Trying this on a stock block will result in meltdown faster than you can blink.

Andy

Yeah I should have elaborated more. Cast pistons hate that kind of heat almost as much as I hate the cold of this stupid winter.