Need help- Twin Tec advance curve settings for new motor?

[LA_Dog]

I'm at a bit of a confusing point with what to set my advance curve at initially- Daytona Twin Tec 1005.
Anyone have suggestions for a good initial starting point?

My static comp will be 10.45:1, cam corrected 9.58:1, 200psi CCP.
107" Evo
Cam intake close is 41
Overall gear ratio is 3.34

Daytona states the following suggested parameters for different motor builds:

Maximum Advance at WOT
Stock Compression (less than 10:1 using premium gasoline)
35 deg BTDC at 2500-3000 RPM

High Compression (10.5:1)
30 deg BTDC at 5000 RPM

High Displacement (>120 CID or bore approaching 4 inch)
28 deg BTDC at 5000 RPM


There are two types of adjustable maps in the ignition, "Street" and "Race". I don't see a lot of diff other than with Street mode the advance comes on sooner / steeper. The Max Advance can also be set lower to like 28 max @ WOT

Race maps come on more gradually and can be set higher for Max Advance, but I can't go any lower than 30 Max @ WOT

It would seem given the suggested parameters above, I would want to use "Street" to keep the full Max Advance around 28? But the Race maps look better suited to high comp / big inch as far as slower advance curve ramp-up.

I can also program a custom map and upload it.

Here is an example of the "Street" map at its lowest advance setting, when my VOES kicks in (high vacuum) it will also follow the blue increased advance line.

Here is an example of a Race map set at it's lowest advance setting "0":

And here is a Custom map from Twin Tec suggested for "High Displacement Motors" - notice the High Vacuum curve (blue line, max advance) is fast while low vacuum (WOT) is slow ramp up. And the overall full advance is lower at 28

 

[Bhawkins854]

I have the Daytona twin tec ignition module installed as well. If I can remember right my mechanic told me to set it for race mode, and adjust the slope until you hear a ping and then back it off. I had issues with that ignition, remember the directions tell you to set the motor TDC compression stroke on the front cylinder and adjust the module forward and backwards until the little Status light comes on and goes out.. That's the part missed. You seem to know a lot more than I do about it, I still need a good dunno tune to see how far off my adjustments actually are. Seems like a better set up timing off the cam than the stock ignition that was by my battery,.. Still not sure how that old module worked, timed off the crank sensor or some shit..

 

[LA_Dog]

Yep I don't know all that much about it other than the basics. I was told to use Race Mode with Advance Curve 2 for initial setting. I think all of these nose-cone aftermarket ignitions need to have the initial static timing set by rotating unit until the light goes out so it's not something specific to the Twin Tec.
I got the PC Link cable for it and the software is free (that's where I got the map screenhots) - So I'll eventually be able to dial in the most optimal map. Relying on ear to listen for ping is not the best method- tell me you can hear slight ping while riding at speed - especially with loud pipes - and you've got superman hearing

I'm hoping someone on this forum has built big inch or high-comp evo motors and can chime in on what the general best rule of thumb is in regards to max full advance, slow curve vs fast, etc.

 

[Diesel Dan]

I would just call Daytona and speak with them..386-304-0700.......they probally could get ya setup real fast and give ya a good baseline to start with,and fine tune it from there..............there website has a great Tech/Faq section also...........Good luck man..........

 

[LA_Dog]

Already called Daytona several times. They have one tech person, never available and really does not do much beyond answer basic questions.

 

[Diesel Dan]

WOW.............THAT SUCKS.................hmmmmmmmmmmm Try (Andy) BigDogTech.........he has a done a bunch of those ignition Install's and has experience with them,maybe he can help ya out........

I would like to know myself also.......I just got done building my own Dual Dyna Coil setup,and was wanting to get a Daytona Twin Tec for my 2004 Ridgeback,then Iam gonna put it all on there together..........keep me posted on what ya wind up doing........Good Luck

 

[LA_Dog]

cool- I will post it all up in my thread that I have on documenting the rebuild. I have to say though, it pales in comparison with my experience using Branch Okeefe for head work. They totally jacked me around and didn't do the work- then lied about it, and had an attitude on top of it all. I had to go pick up my heads and bring them to another place. they wasted almost a month of my time.

 

[Diesel Dan]

That sucks dude...........BigTime..........If you ever have Performance Engine questions contach forum member John Sachs.........He is a Engine Guru.....he builds Competition Engines,heads and shit all the time......he can steer ya in the right direction also......He"s a good dude,has a tremendous amount of knowledge.........

 

[LA_Dog]

That sucks dude...........BigTime..........If you ever have Performance Engine questions contach forum member John Sachs.........He is a Engine Guru.....he builds Competition Engines,heads and shit all the time......he can steer ya in the right direction also......He"s a good dude,has a tremendous amount of knowledge.........

Yup I hit up JS from the start- He was kind enough to reply but unfortunately no luck since he does not know anything about my heads or motor, so could not offer any guidance.

 

[bigdogtech01]

Am I to late with this reply?
Base timing is just that. If you want 100% out of this motor (sounds like you do, considering the amount of $$ you have already spent) you will need to go to a good dyno shop. Make sure they know what they are doing, not just giving you a max HP. Anyone can do that. You need a shop with a Dyno that is new enough and advanced enough it has a load control. Otherwise, you will not get real road conditions without it. With load control, you can Dyno tune in select gears to not only adjust the fuel/air, but also the ignition timing. On advanced EFI tuning modules, you can adjust timing and fuel/air in every gear and every RPM range. A good Dyno shop will spend a few hrs and cost you $400-500.
To answer your question about the "Base" timing, set Advance slope to 7 and Mode to 3.
You can run without the VOES as well...Just Don't hook Purple/white wire up to VOES. It all depends on what you plan to do with this bike. Are you street racing from bar to bar, or will this be a 300 mile a weekend bike? If you plan to use only for street racing, don't use the VOES. There are other option for VOES as well. Do you know what switch you have in bike?

 

[LA_Dog]

Hey brother- Never too late for sage advise and knowledge

I have the MC07 VOES switch @ 6.5hg. Bike weighs about 820 with fluids and me on it.

Not much freeway riding and ermm.. not much racing (honest, officer!) - mostly around town riding and some 100-300 mile weekends along the coast. Running 10.45 static, 9.58 cam corrected, 200psi ccp

So I'm looking at the chart layout for Twin Tec Race Mode 7 / curve 3. Shows VOES / high vac full advance of 31.7 by 3k RPM. The WOT map ramps up to full 31.7 by 5k RPM. In contrast, using curve 0 ramps to max advance at the same RPM points as curve 3, but the max full advance is limited to 30.

Is curve 3 too much full advance- e.g wouldn't I want to keep the max advance at 30 or less?

Also for setting base timing on the motor- shouldn't it be 30 or 32 degrees BDTC instead of 35?

I guess that is what is throwing me given the higher corrected compression of the motor and I don't want to ping / detonate

I will definitely do a proper dyno but I gotta put 1k miles on the motor first right? So this is more to figure out the right initial settings to get things running and break in.

 

[bigdogtech01]

Hey brother- Never too late for sage advise and knowledge

I have the MC07 VOES switch @ 6.5hg. Bike weighs about 820 with fluids and me on it.

Not much freeway riding and ermm.. not much racing (honest, officer!) - mostly around town riding and some 100-300 mile weekends along the coast. Running 10.45 static, 9.58 cam corrected, 200psi ccp

So I'm looking at the chart layout for Twin Tec Race Mode 7 / curve 3. Shows VOES / high vac full advance of 31.7 by 3k RPM. The WOT map ramps up to full 31.7 by 5k RPM. In contrast, using curve 0 ramps to max advance at the same RPM points as curve 3, but the max full advance is limited to 30.

Is curve 3 too much full advance- e.g wouldn't I want to keep the max advance at 30 or less?

Also for setting base timing on the motor- shouldn't it be 30 or 32 degrees BDTC instead of 35?

I guess that is what is throwing me given the higher corrected compression of the motor and I don't want to ping / detonate

I will definitely do a proper dyno but I gotta put 1k miles on the motor first right? So this is more to figure out the right initial settings to get things running and break in.

Street advance of 7 and Street Mode of 3, not race...you do not have a race motor with 14:1+ compression. You will be using Street timing.
You will static time first at TDC front cyl. And then using a timing light, ground VOES if not in use, set mode switch to 6 and advance slope to 9. You want it on single fire and timing light set to 0. Yes you will be looking for the 35* BTDC mark.

 

[john sachs]

LA,
Go see Bill Greenrocks at Greenrocks Perfomance Services in Ventura. He's a great dyno tuner. He knows what's up.
John

 

[LA_Dog]

Street advance of 7 and Street Mode of 3, not race...you do not have a race motor with 14:1+ compression. You will be using Street timing.
You will static time first at TDC front cyl. And then using a timing light, ground VOES if not in use, set mode switch to 6 and advance slope to 9. You want it on single fire and timing light set to 0. Yes you will be looking for the 35* BTDC mark.

Thanks bud- Ok I sincerely appreciate the pointers but I am now extra confused. I've got Twin Tec telling me to use Race Mode (7) with Advance curve (2), and to not use Street maps - but as I stated earlier they really only gave me "basic" info based on what I told them about the motor. They even directed me to the above posted "custom" map for motors at or over 4" bore and higher compression. The main diff I see is that Street maps bring the advance in full much sooner at lower RPM. Race maps bring it in more gradual and later in RPM. The "custom" map has a full advance limit of 28 WOT.

Given my actual cam corrected compression is 9.58 with 200psi CP, that is in the high comp category no? I mean you can have 14:1 static but a cam that has a late intake close and corrected comp of 9:1 / 190psi CP.

Not trying to be argumentative, just trying to understand the logic behind all of this (e.g. why use a street profile vs race profile, and why set max advance limits lower vs higher?).

I'm gathering that a "hotter" motor would want a specific type of map vs a stocker, so you can run a higher corrcted comp and won't need as much full advance? (brain now scrambling...:loony

 

[LA_Dog]

LA,
Go see Bill Greenrocks at Greenrocks Perfomance Services in Ventura. He's a great dyno tuner. He knows what's up.
John

Thanks J - Will definitely check them out.

 

[bigdogtech01]

Thanks bud- Ok I sincerely appreciate the pointers but I am now extra confused. I've got Twin Tec telling me to use Race Mode (7) with Advance curve (2), and to not use Street maps - but as I stated earlier they really only gave me "basic" info based on what I told them about the motor. They even directed me to the above posted "custom" map for motors at or over 4" bore and higher compression. The main diff I see is that Street maps bring the advance in full much sooner at lower RPM. Race maps bring it in more gradual and later in RPM. The "custom" map has a full advance limit of 28 WOT.

Given my actual cam corrected compression is 9.58 with 200psi CP, that is in the high comp category no? I mean you can have 14:1 static but a cam that has a late intake close and corrected comp of 9:1 / 190psi CP.

Not trying to be argumentative, just trying to understand the logic behind all of this (e.g. why use a street profile vs race profile, and why set max advance limits lower vs higher?).

I'm gathering that a "hotter" motor would want a specific type of map vs a stocker, so you can run a higher corrcted comp and won't need as much full advance? (brain now scrambling...:loony

Every motor can end up a little different from another. That's why you are setting this as a "Base" setting. You will need to ride it and see how it feels. If you are getting a spark knock, you will need to make some adjustments. Once motor is broken in ( you should have the rings broken in by 250 miles) Can Dyno tune around 500 with top end R&R, 1000 with Top and Lower R&R.
If the shop Dyno tuning it feels the ignition needs to be adjusted, they will. It might work better on race mode. It might work better on Street. I have seen it both ways, but most common to use Street.

 

[LA_Dog]

got it- thanks. Between the two modes, what is the least agressive? I guess I'm trying to understand the logic of Race mode bringing in advance slower vs Street bringing it all in sooner.

Also where does one "draw the line" for a high-comp motor vs a regular comp motor? When we talk high-comp, are we only talking static or are we also talking operating comp and cranking comp as dictated by the cam events? From what little I have learned is seems static comp by itself does not mean much (and i'm trying to expand my knowledge).

 

[bigdogtech01]

got it- thanks. Between the two modes, what is the least agressive? I guess I'm trying to understand the logic of Race mode bringing in advance slower vs Street bringing it all in sooner.

Also where does one "draw the line" for a high-comp motor vs a regular comp motor? When we talk high-comp, are we only talking static or are we also talking operating comp and cranking comp as dictated by the cam events? From what little I have learned is seems static comp by itself does not mean much (and i'm trying to expand my knowledge).

Have you thought about taking some classes at MMI? I had to spend 6 weeks, 5 hrs a day, 5 days a week in theory plus another 51 weeks before graduating and 13 years after that....And you want this explained in one post? :bang:
Mechanical compression is all mathematical. Were you given any numbers from the guys who built the motor? You need to know the actual cylinder displacement and net combustion chamber volume in order to figure out your mechanical compression ratio. You take cyl disp. + net combustion camber volume and divide it by the net combustion chamber volume. But yes, cams do affect the actual numbers. In some cases, because of the large cam in a stock compression motor, compression will actually drop.
You might be able to find a book at Barnes and Noble or something on this as well

 

[LA_Dog]

LOL- no I definitely don't want to know all of that- My knowledge begins and ends as this relates to my specific motor. I apologize as I thought my question was simple. you mentioned earlier that my motor is not high comp since it's not up in the 14:1 static range. But I've got the cam maker and T.P engines saying it will be a high comp motor because it will be running at over 9.5 dynamic comp / 200psi cp @300ft above sea level. I wanted to get your thoughts since I know you know what you're doing

I was curious where the "demarc" point is on high comp vs normal comp motors for you experts in the know, and if you only take the static comp into consideration.

I did all the math for the motor so I do have all the numbers, displacement, volumes etc. I've worked hand in hand with my mechanic on the build specs and also spent a lot of time with TP, T-Man, S&S obtaining the exact specs on the heads, block, jugs, rods, crank, piston specs, cam specs, etc etc. So when I'm making statements about my anticipated comp numbers it is based on the result of those calculations. Just so you know I'm not simply pulling those numbers out of my ass.. lol

 

[LA_Dog]

Here's some of the specs and numbers I used for calculations- I have some more for the heads (flow numbers, valve sizes, angles etc, Baker trans gear ratios, bike weight, etc.

Please keep in mind this is a first time for me on this, and I am the last person to claim I know what I'm doing beyond 'enthusiast level' knowledge. if I missed anything important for basing my comp numbers definitely let me know.

Motor Specs:
S&S Piston size: 4.030
S&S Piston valve pocket relief CC per piston: 1.7cc
S&S Piston wrist pin to deck height: 1.200 (measured from centerline of wrist pin) = .804 from top of wrist pin to piston deck
S&S Piston Top Ring Land: 1.65"
S&S Rod length: 7.440
TP Case deck height to crank centerline: 6" (higher than typical S&S 5.875")
TP Cylinder length: 4.885" from factory, trimmed .12" for piston zero deck
TP Cylinder Bore: 4.0325"
Stroke: 4.250"
Final Piston Deck Height F/R: 0.00"
Cometic Head Gasket Bore: 4.090"
Cometic Head Gasket thickness: 0.030"
Cometic base gasket thickness: 0.020"
Edelbrock head chamber volume: 86cc
Assembled quench: 0.030"
T-Man 625 Cam intake close event: 41.0 ABDC
Engine CID: 108.6
Combustion space: 96.16cc
Cylinder Volume: 890.13cc
-----------

Static Compression = 10.45:1
Cam Corrected Compression = 9.58:1
Cold Cranking Compression @ 50ft = 200.4

------------
Cam Events:
Intake - Open/Close: 23/41 Lift:625 Duration:244 Centerline:99 TDC:212 LSA:100.5 Overlap:44
Exhaust - Open/Close: 45/21 Lift:625 Duration:246 Centerline:102 TDC:196
Cam Advance: 1.5

------------
Calculated Head Intake Valve Mach Index / Volumetric Efficiency Max: 0.61 @ 5200 RPM (this could be improved above 5200 RPM by enlarging intake valve to 2.2" or select cam with later closing intake event)