anybody know how much timing to run on a 1g 2.3 stroker 8.8:1 compression

[DSM97GST]

I just wanted to know what kind of timing you need to run on a 2.3 stroker with a 8.8:1 compression. I guess 1gs have alot of timing and if you dont retard the timing a little you run into problems is this true?

 

[JayRolla]

Yes it is true. The 1g timing is more aggresive than a 2g because it has lower compression. If you are asking what kind of timing you should run then you must have some type of timing control. The amount of timing a car can run is different from car to car. The best timing is where you can make the most HP and torque without getting any knock. On pump gas you want to see around 18* max and on race gas or meth I would say 22-26* or what ever you can run depending on set up. I guess the only way to tell is get on the dyno and see what you can run.

 

[andymoraitis]

On pump gas you want to see around 18* max and on race gas or meth I would say 22-26* or what ever you can run depending on set up.

Most of us run our strokers at lower timing. The amount of heat the turbo generates will have a direct affect on combustion temps so this changes the equation as well. My setup runs 8 degrees on pump, Jake Hanhardt (topstreet) runs between 10-13 on his and Dan Kasun (project_tsi) runs 12 on his with no meth although I'm sure he'll add more timing with the methanol running. When I told the guys at Buschur I was running 12, their exact words were "wow, that's a lot of timing on a stroker."

The point is that if you can still be on the compressor map, boost will make more power than timing on pump. As Jason mentioned, the 1G curve is way too much since it peaks at 22-23 degrees of advance above 2.06 g/rev. With a built bottom end I would start with a max of 12 and see what you can get away with while still keeping the turbo on the map. 30 psi at 8 degrees will certainly make more power than 25 psi at 12 degrees. On race gas or methanol, turn them both up to the point at which max power and torque are made without knock.

If you're still using a stock ECU, you'll need something like Link or a Keydiver chip to cap timing. An AFC or MAFT will only make the timing curves worse and run you into knock sooner.

It's a bit of a trade off, but with time and tuning you'll find what the motor will tolerate and what it likes best.

Andy

 

[JayRolla]

This is where im confused cant you make more torque with more timing. 8* is nothing. You may gain more HP but im a torque guy and doesnt the timing help with that. Well with a stroker I guess you dont have a problem with torque.

 

[andymoraitis]

Timing is always helpful in creating torque but with the increase in displacement it's not an absolute requirement. When I hit bigger airflow numbers, I could no longer support 12 degrees at my current boost levels. Rather than drop the boost I reduced timing. This isn't to say that the motor doesn't like timing but if you had a choice between either boost or timing, you add boost and take timing away (to a point). Going below 8 would be foolhardy, but trying to run 18-20 on pump would be as well since you'd need to reduce boost a great deal to do so.

Again, the greatest factor in pump gas tuning is based on how cool you can keep air intake temps and how efficient the compressor is at generating boost without making tons of heat. If you can run methanol, then you can have boost and timing all in the same equation. In my perfect scenario, I'd run 16-18 degrees of timing at 30 psi with methanol injection. Since I can't get away with it on stright pump, I chose to keep the boost higher and the timing lower.

See what I mean?

 

[JayRolla]

Yep I see what you mean. That would be a great scenerio. Ill run very low boost till I get my methonal, since im not going to have timing control untill i get an eprom

 

[andymoraitis]

I was thinking about couple of other things while I was at work that may give you insight as to why I run the timing I do. If you consider that I have an 8.8:1 motor with aggressive advance on the intake cam this nets me 190 compression across with Comp 200's. That extra compression means more cylinder heat so there has to be a tradeoff somewhere in the absence of methanol or race gas. I think you'll find that most people running strokers with aggressive cam setups will have fairly close compression numbers (although mine are a bit high) and they'll need to pull a bit of timing to deal with the issue on pump.

 

[95 gsx]

I was thinking about couple of other things while I was at work that may give you insight as to why I run the timing I do. If you consider that I have an 8.8:1 motor with aggressive advance on the intake cam this nets me 190 compression across with Comp 200's. That extra compression means more cylinder heat so there has to be a tradeoff somewhere in the absence of methanol or race gas. I think you'll find that most people running strokers with aggressive cam setups will have fairly close compression numbers (although mine are a bit high) and they'll need to pull a bit of timing to deal with the issue on pump.

As long as we're on the subject, do you run 8* with your base set a 5* BTDC? You tune with link, correct? I kinda understand what you're saying here...it's important to have some sort of timing control with a 2.3 other than SAFC and MAF-T to keep things within reasonable levels because those would just modify the airflow that the MAF would see and trick the computer into seeing less airflow, in turn advancing spark. I assume link would fix that.

 

[ba109296]

Yes link is an easy way to fix this. Along with that you will get alot more tuning parameters to mess with.

 

[andymoraitis]

As long as we're on the subject, do you run 8* with your base set a 5* BTDC? You tune with link, correct? I kinda understand what you're saying here...it's important to have some sort of timing control with a 2.3 other than SAFC and MAF-T to keep things within reasonable levels because those would just modify the airflow that the MAF would see and trick the computer into seeing less airflow, in turn advancing spark. I assume link would fix that.

I don't use Link preferring instead to run a custom Keydiver chip with capped timing and embedded A/F tables for my setup. I do run 5 degrees base as does every other 2G, but max timing is 8 degrees in the absence of knock. If you looked at one of my logs, you'd see my car switch from about 30 degrees of timing to around 2-3 at WOT and then hit that max of 8.

 

[drivemusicnow]

Something I learned after talking to an extremely good engine tuner (doesn't typically work with DSMs all that much) Is that most people that "Street tune" their cars using standalones or reprogrammable stock ECUs tend to run too MUCH timing. From his experience using his dynodynamics chassis dyno (bad ass peice of equip... He also sells them) is that usually more power/tq is made by reducing timing on FI engines. This is not "fact" nor is it meant to be anything other than an observation that he's made, but I trust his, and Andy's opinions, and will be using a similar timing map.

 

[andymoraitis]

Greg,

I think you make a very good point about people trying to stretch it on timing. While I understand that these motors like timing and make much more torque I don't think too many people understand the tradeoff that's required. I know I keep saying this, but I would rather have less timing and more boost. It's much more forgiving on pump gas and it allows me a decent safety margin. Running 8 degrees and hitting a few counts of knock on pump doesn't worry me, but if the same thing happened running 20 degrees of timing I'd be more concerned. I think this is a byproduct of so many people running piggybacks since they create a constant tail chase for the optimal tune.

If you look at my setup, you'll see that I'm pretty much up against a wall right now. I can add more boost, but only a little bit more to say 28 or 30. After that I'll make nothing but heat and end up off the map on the 50 trim. The only other option left open to me is to add timing to bump the torque a bit. It's a real balancing act if you ask me! Truth be told I could run the motor pig rich and toss more timing at it, but I doubt it would make any more power since I'd be drowning knock with fuel.

This motor really needs a bigger turbo. Sigh...

 

[JayRolla]

Well see this is where im confused again. Cant you make the same amount of power with less boost and more timing? I know you will say no but I want proof. My brother made 300whp/300tq at only 17psi on his evo16g. Stock internals. The tuner added timing because when we log he hits like 26*. I think this is real high, but he made good tq and hp at a low boost. He said we would gain hp but lose boost if he took timing out and added boost.

 

[drivemusicnow]

Well see this is where im confused again. Cant you make the same amount of power with less boost and more timing? I know you will say no but I want proof. My brother made 300whp/300tq at only 17psi on his evo16g. Stock internals. The tuner added timing because when we log he hits like 26*. I think this is real high, but he made good tq and hp at a low boost. He said we would gain hp but lose boost if he took timing out and added boost.

There are a lot of variables, and the only way to figure out the "best" way is to sit it on a dyno and do load based tuning. Here is what it comes down to though:

Turbo efficiency: An EVO3 turbo is more efficient running 17 psi than it is at 20 psi. This specifically means that while there is an increase in horsepower between 17 and 20 psi, it is not linear.

Engines VE: I think this should speak for itself, but the volumetric efficiency of the engine will directly effect its preferences for fuel, timing, and boost.

Engine displacement: A 2.3/2.4L has different requirements for air/exhaust flow than a 2.0L engine, using the same head. A

Fuel: The octane of the fuel that you are going to be running

Application: How is the engine going to be run? Drag/street/roadrace etc Different types of applications respond better to different tuning.

Because there are sooo many things that go into determining whether more timing or more boost is better, there is no "right" answer. I agree with Andy that the positive trend tends to lie with pump gas = more boost and less timing, while with race gas, you run the same boost, and bump the timing up.

Other than looking at a bunch of logs of people with very similar mods, or dyno tuning (track tuning works also) you'll never REALLY know what works best on your car. Heck, maybe if your brother bumped the boost up to 23lbs decreased timing by 6-8* he might make a bunch more power... Or maybe not so much...

 

[andymoraitis]

Adding timing will make power, but it mainly adds torque. A combination of the two is great, but if you have the choice it will always be boost over timing on pump. I've run 20 psi at 12 degrees and 26 at 8 both with the same tune and knock counts. The airflow at 26 is greater than it is at 12 and if 4 degrees of timing can make more power than 6 psi, I'll hang up my hat.

I'll put it this way. If you can have both, great. If you can't, running more boost with less timing is the answer (especially on pump gas) as long as the turbo isn't off the map. One of these days, I'll take the car to a dyno and get readings on both setups so you can see the difference. Granted the 8 degree tune will have less torque but the run with greater boost will make more horsepower.

 

[andymoraitis]

There are a lot of variables, and the only way to figure out the "best" way is to sit it on a dyno and do load based tuning. Here is what it comes down to though:

Turbo efficiency: An EVO3 turbo is more efficient running 17 psi than it is at 20 psi. This specifically means that while there is an increase in horsepower between 17 and 20 psi, it is not linear.

Engines VE: I think this should speak for itself, but the volumetric efficiency of the engine will directly effect its preferences for fuel, timing, and boost.

Engine displacement: A 2.3/2.4L has different requirements for air/exhaust flow than a 2.0L engine, using the same head. A

Fuel: The octane of the fuel that you are going to be running

Application: How is the engine going to be run? Drag/street/roadrace etc Different types of applications respond better to different tuning.

Because there are sooo many things that go into determining whether more timing or more boost is better, there is no "right" answer. I agree with Andy that the positive trend tends to lie with pump gas = more boost and less timing, while with race gas, you run the same boost, and bump the timing up.

Other than looking at a bunch of logs of people with very similar mods, or dyno tuning (track tuning works also) you'll never REALLY know what works best on your car. Heck, maybe if your brother bumped the boost up to 23lbs decreased timing by 6-8* he might make a bunch more power... Or maybe not so much...

Very nicely said Greg.

Efficiency of the air charge, VE of the motor and efficiency of the compressor wheel within the housing will dictate just how much you can get away with. Swapping an E cover to an S cover on a large turbo like a GT3561 will make considerably more power (somewhere in the neighborhood of 50 HP according to information on Dejon's site). It's all about the efficiency of the setup and what the motor will tolerate.

What I like to do is find the turbo and motor's sweet spot. By logging for airflow, timing and RPM, I can see what adding boost does to the motor on the same tune. If I find that going from 20 psi to 26 psi moves the airflow from 40 to 46 lbs/min, I'll continue adding boost until I see that I'm running out of efficiency or that I'm not gaining anything. Once that happens, I'll go back to the point at which I was seeing maximum airflow gains and lock the boost there. At this phase, I'll start to play a bit with timing and see how much more I can add before knock becomes a factor. So in essence, I'm trying to maximize the VE of the setup while keeping knock at bay and then adding back some power until I see the threshold of 2-3 counts of knock at the top of third. Once I hit that range I pull a degree or two of timing for safety margin or richen the A/F with a bit more fuel pressure (no more than 1-2 psi over base) until I see zero knock.

At that point, I've maximized the combination on pump gas and those are pretty much the settings I have burned into my chips. Keep in mind that because I run a chip only tune it sometimes takes a few attempts to get it just right but after a while you'll develop a strong tuning instinct and know what the motor likes on pump.

A recent log showed that at 25 psi (I get 26 in cold weather from the increase in air charge density) I saw 46 lbs/min in 55 degree air on the current tune. Now I know my 650's have almost had it so when I change those for 750's and swap in a 1G TB this weekend I'll pull another log and see how it looks with respect to airflow and timing. If I see zero knock on that tune and airflow around 48-49 lbs/min, I'll add some more boost to see what she does. Once I reach the law of dminishing return with respect to airflow, I'll have Jeff send me two more chips (one with 12 degrees of timing and one with 10) to see what she'll tolerate. Since the A/F is already at 11.5:1, I won't see much gain from yanking more fuel but I'd certainly get a bit of a kick from adding 2-4 degrees of timing.

 

[turboAWDfanatic]

Sorry to revive an ancient thread, but I have a question that is relevant to the above information.

I have been working on getting a safe tune with my 2.3L stroker with 8.9:1 compression on a 16g at 20psi with 660 injectors, tuned with TunerPro on an Ostrich.

I'm running into some trouble when I retard the timing significantly. I start to get *really* high EGTs if I retard timing any less than 12 degrees (with no knock). I know that typically high EGTs are a symptom of the ECU retarding timing due to knock and that monitoring EGT is a bit of a moot point once you have a wideband and timing control, but is it safe to see extremely high EGTs from running less aggressive timing on purpose? When I run anything less than 12* of timing, I get 940+ degrees Celsius from my EGT once I hit 5k RPM at WOT. At what point are you wasting power by dumping partially combusted fuel out the exhaust manifold? Should be concerned by the high EGTs, or ignore them since I have a wideband and direct control over boost, timing, and AFR's?

 

[Mindslayer]

I'm having the same problem with my 880.

 

[Lurker]

I have stroker motor with 880cc injectors and gt3076 turbo. I think different EGT probe would read differently. My EGT gauge reads about 50 degree-C higher after I switched to the more responsive EGT probe from TRE. Previously, I used Greddy EGT probe, which reads much slower.

Which EGT probe do you have ?