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-   -   12at timing (https://www.rx7club.com/1st-generation-specific-1979-1985-18/12at-timing-899039/)

Bearzah 04-19-10 03:28 PM

12at timing
 
I just want to revisit this topic... Where is best to run timing?? (engine/car description in my signature below)... 7psi boost all day.... Thinking of bumping that up too & looking for recommendations.
i currently running a locked stock dizzy @ 10* leading w/ 8* split through MSD blazter 2 coils.
Im seeing a lot of 12a turbo write ups praising 15-18* leading timing or even HIGHER. I'm looking for someone with experiance to explain/recommend where i should be setting my timing.
Thanks for all ur help guys
-Chris

arghx 04-20-10 06:36 PM

what fuel? 9.4:1 compression right

RW-7 04-20-10 07:41 PM

Yes on a Non turbo streetport you can go up near 18 or so advance and get a bit more power while retaining a smooth torque curve, however you have a turbocharger and things ar different with forced induction. To avoid predetonation I would not recomend going much more that the 10* you have so far. Infact that sounds about right for your setup.

Bearzah 04-20-10 08:01 PM

Super (92 octane) always... Premixing Lucas 2-stroke oil.
Stock compression... Yes 9.4:1

and Rob, it runs great and i know 10* advanced locked is a SAFE setting, was curious if anyone knows where i can go before BOOOM :-p

bad 83 04-20-10 08:04 PM

Stay with 10* leading and run a 10*split. That will be great for up to 15 psi. I ran this timing on my old blowthrough setup for a couple of years with no problem.

joemaddox 04-20-10 08:15 PM

go boom so we can go b-port!!!! lmao ;)


i know i am a dick... and currently without a running seven, so dont listen to me:lol:

Bearzah 04-20-10 08:26 PM

Kinda thinking stay at 10* lock on dizzy.

I run around at 7psi all the time and notice quite a jump in power when i up to 10 psi on the fly with my EBC.
Anyone have experiance what SAFE boost PSI for N/A rotored (and streetported) 12a?
Carb tuned with Wideband at 12.3-12.5:1 at WOT THROUGHOUGHT boosted RPM range.

Bearzah 04-20-10 08:28 PM

And Joe... Yes it will be replaced with a b-ported 12a when it pops... Thats NOT saying i have the money to replace it RIGHT NOW ... :-p

RW-7 04-20-10 10:02 PM

I would just be vary careful in finding out how far you can go. If you had a stand alone with a knock sensor and fuel cut if it were to knock, than you would be safer. One thing you might do is have it dyno tuned. Just go a tiny bit 2-3* or so at a time and see where that gets you. I was able to pull 12hp out of my GSL-SE by tuning the timing and air/fuel alone, but like I said just be careful it only takes one knock under boost to ruin a motor. Good luck.

Verneuil 04-20-10 10:15 PM

This is kinda weird, When i was readin on boosting my old Nissan pickup they were talkin about retarding the ignition about 3 degrees for every pound of boost. So you can run it advanced as crap but when the boost came on it would retard it to prevent knocking. Any try this with FI or carbed?

PercentSevenC 04-20-10 10:27 PM

I ran 15 degrees total advance with 10 degree split at 9 PSI with a 7" Camden supercharger and 9.2:1 CR. Never had any problems but I feel like I was pushing my luck with such an inefficient compressor. Now I've got an S5 turbo blowing through a 45 DCOE. I'm getting some issues ironed out so I'm only running 6-7 PSI with the timing locked at 10 degrees. Once I get my AFRs where I want them, I plan on running a "semi-locked" dizzy, gradually increasing to 15 degrees advance, 12 degree split at 10 PSI. Might try playing with boost retard, too, but I'd have to add another nipple to my intake manifold.

Your AFRs seem pretty lean for a non-intercooled NA-turbo setup. I'd richen those up first if you want to add some timing.

PercentSevenC 04-20-10 10:35 PM


Originally Posted by bad 83 (Post 9945594)
Stay with 10* leading and run a 10*split. That will be great for up to 15 psi. I ran this timing on my old blowthrough setup for a couple of years with no problem.

Did you run an intercooler? What were your AFRs and what turbo?

j9fd3s 04-21-10 12:25 AM


Originally Posted by Bearzah (Post 9945665)
Kinda thinking stay at 10* lock on dizzy.

I run around at 7psi all the time and notice quite a jump in power when i up to 10 psi on the fly with my EBC.
Anyone have experiance what SAFE boost PSI for N/A rotored (and streetported) 12a?
Carb tuned with Wideband at 12.3-12.5:1 at WOT THROUGHOUGHT boosted RPM range.

12.3-12.5 is lean for a turbo, so you should leave the timing where it is.

the t2's run about 7psi, and with 8.5:1 rotors, they run like 11:1 afr...

so either leave it alone, or add some fuel before you play with timing.

Bearzah 04-21-10 09:52 AM

roger that... adding fuel... Piece of cake.

Will update this afternoon once I richen it up.. I will target 11-11.5:1 at WOT under boost.

:)

j9fd3s 04-21-10 10:53 AM

what spark plugs are you running?

Bearzah 04-21-10 10:57 AM


Originally Posted by j9fd3s (Post 9946815)
what spark plugs are you running?


NGK BUR9EQ all around

bad 83 04-21-10 02:13 PM


Originally Posted by PercentSevenC (Post 9945999)
Did you run an intercooler? What were your AFRs and what turbo?

Front mount intercooler (A must). AFRs never got out of the mid 12s at 15psi. I was using a S4 turbo with a 35mm ported wastegate. I played with blowthroughs along time ago. BTW, this was with the Nikki :D

http://img.photobucket.com/albums/v6...7/P1010002.jpg

http://img.photobucket.com/albums/v6...7/P1010001.jpg

http://img.photobucket.com/albums/v6...EngineBay4.jpg

Bearzah 04-21-10 05:48 PM


Originally Posted by bad 83 (Post 9947230)
Front mount intercooler (A must). AFRs never got out of the mid 12s at 15psi.

Drawthrough setup... no intercooler

PercentSevenC 04-21-10 08:25 PM

I'm not using an intercooler, either. But I'm also not running 15 PSI.

That's a pretty sexy setup, bad 83. Did you ever get it to a dyno?

Verneuil 04-21-10 09:01 PM


Originally Posted by bad 83 (Post 9947230)
Front mount intercooler (A must). AFRs never got out of the mid 12s at 15psi. I was using a S4 turbo with a 35mm ported wastegate. I played with blowthroughs along time ago. BTW, this was with the Nikki :D

http://img.photobucket.com/albums/v6...7/P1010002.jpg

http://img.photobucket.com/albums/v6...7/P1010001.jpg

http://img.photobucket.com/albums/v6...EngineBay4.jpg

So could you help with a possible build. Kinda give a hand on what you bought where and if you have any tips on doin this.

openshot 04-21-10 09:45 PM

i want i want

Bearzah 04-23-10 11:21 AM

bump on boost psi recommendations / timing

j9fd3s 04-23-10 07:53 PM


Originally Posted by Bearzah (Post 9951658)
bump on boost psi recommendations / timing

with no IC, i'd stay @7-8psi with like AFR in the 11's and timing at like 10-12L with a 15 degree split.

AcidAngel7477 04-25-10 08:44 PM

does this apply to non-turbo streetported and stockport 12a's? dont mean to thread jack i just want to be sure.

:AA:


Originally Posted by RW-7 (Post 9945532)
Yes on a Non turbo streetport you can go up near 18 or so advance and get a bit more power while retaining a smooth torque curve.


PercentSevenC 04-26-10 10:54 AM

No. You normally run a lot more timing on an NA car. I ran 24 degrees when I was NA, some go as high as 30.


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