We put the timing at 40 degrees at the upper rpm band through the FAST timing table. We backed it down to 38 degrees. We gained 35 HP ad 40 ft/lbs of torque by adding timing and fuel up top.

Thanks for the compliment. The most Wicked sounding built motor I have had in this Sled.

 

I highly doubt it "wants" more than 40 degrees....

What do the plugs look like...?

 

The NGK TR6 plugs look good at 38 degrees timing.

It "wanted" more timing because it kept making power on each pull were we added timing. We had to stop at 40 degees with no race gas on hand. Will this 12.5 to 1 motor make more power at 40 degrees with better gas? Not sure, but I will keep you posted

 

You need to know what the plugs look like. It could "want" a lot less fuel which would give the same results of throwing timing at it, speed up the burn. I would be very careful with it. You can see the detonation on the dyno sheet.

 

gregrob, I appeciate your concern and I know you don't know me or the dyno operator in the vid. But how can you assume that someone you have never met doesn't check and read plugs, or makes proper EFI fuel or timing adjustments?

I check plugs constantly NA and on the bottle. They looked great after these pulls and every day since. Yes, there was detonation on the blue runfile at 40degrees. That is why we backed it down to 38 degrees in the red runfile.

The dyno operator, who is the race shop owner is one of the most respected EFI tuners in the Southeast. He is a Ford Guy though, so you never know

 

I can assume that because far more people do things the wrong way, then the right way. It's a lot of work to check all the plugs while doing the tune. Most people tune with a wideband and get that at some arbitrary figure they think is good, then start throwing timing at it until some undesirable condition arises, usually knock. Then they back it off a little and "call it good". I have seen MANY tuners tune this way, and it's simply not correct.

You saying it was at 40 degrees and still wanted more leads me to believe that you or the tuner either did not check the plugs, did not know what to look for when doing so, that the ignition system is not accurate (which is a bigger issue with many ignition systems than you would think) and/or it is not a load dyno.

Another thing people do is get it "dialed in" on a load dyno, and are never aware that things change drastically when the car is on the street and track. Your car is heavy and that is even more of a concern.

I'm assuming since it's solid roller you have the knock detection hardware disabled. I would hate to see you hurt the engine simply because the proper steps weren't followed.

If it really wants 40 degrees of timing, and the timing mark and fuel ring on the plug is right where it should be, then I would gather those heads have some lazy ports and a very inefficient combustion chamber.

I think the CNC program on the heads is very good, so I dont think that is the case.

I'm just trying to give you ideas, or a perspective you may not have considered before. Aren't we all here to learn? With all due respect, it's just my opinion you can take it or leave it. But if you didn't want feedback why did you post?

Put this up somewhere outside of ls1tech and have some knowledgeable people look at the situation and you will get an entirely different set of feedback.

What is your method for reading plugs? Can you post some pics with them on this tune up?

 

gregrob, you've made a lot of assumptions and informaton based on this thread.

This package was tuned on the street via the FAST system for drive-ability weeks before putting it on a dyno. And yes, plugs were pulled and read. My method of reading plugs is observing all aspects of the plug for issues and info on what's going on in each cylinder.

The dyno runs, as indicated on my original post, were to get a better understandinng on shift points and complete the WOT tuning that could not be done on the street past 7000 rpms for many reasons. And no, I was not going to tie up this Man's dyno to cool the motor down to pull plugs in between runs. Not at that hourly rate.

I do agree with you on the need to constantly monitor and adjust the tune based on changing conditions. I do that regurely on the street and track, expecially with the air down here. Or lack of it. That is the beauty of EFI and why I put it on this Ride.

Knock sensors have been off my car with built motors over 11 years ago. Too much false knock with a SR.

Thanks for the feedback gregrob. You wear me out Dude. I'm going to sleep

 

This. The guy that will be rebuilding my 12 Bolt is a Mustang/Ford guy to the core, I bought a fox body Mustang 5.0 T-shirt to wear when I drop the car off so I stay with in his good graces. I know he can set up gears, but I am sure he's also an LT1 Racist like most Ford guys are. Your build has nailed the coffin on going SR for my 398 build.

 

Hadn't yet taken the time to check your thread yet, Chett. Thanks for posting, glad it is all coming together!

One point, i believe it was 11.5-11.7:1 IIRC. We generally cannot generate much over 12:1 w/ our large chamber 23deg TFS head (which is why we did the 212cc 21deg head).

A note on timing, it is important to consider that without a properly set up pointer, we often don't know what the actual timing is. It is not uncommon for it to be several degrees from commanded timing, as someone else mentioned. On efficiency, a good setup will often tolerate a wide range of timing. The combustion space, spark plug location, and fuel will make a significant difference. Typically our GM LT head makes peak power at 32-36deg in the 6500-7500rpm range on 92 octane, but will tolerate 40-42 max @ wot in the 400-440rwhp SAE range. However, a larger combustion space w/ different fuel may require more. A good example is that it is common to run ~40deg on a much better head, chamber, & piston such as SB2.2's. Far more to it than chamber alone.

Keep tinkering with it - always something to sort out with builds this involved. Glad it is coming along well - those are great #'s w/ your T400 and GVOD!

-Phil

 

Phil is exactly right here, my stuff makes the best power around 34 degrees I have the same 23* TFS 215 you do however my combustion space is much much smaller my compression is 14.2:1......i have noticed that very little timing increase makes a big difference on this motor though.......... i went to the track with 31 in the car......i crept it up .5 degrees at a time and picked up 1mph every shot......got up to 132 at 33 degrees and i still plan on adding the rest back in.......i can tell you that 39* will make my car detonate badly even on 114 octane with a very cold plug equalivent to an NGK 9

like phil said your commanded timing may not be your actual timing........the best way i reccomend is to find tdc using a degree wheel and a piston stop in the plug hole...........then make sure your pointer is on 0*.........start the motor and set your timing trim in the XFI to 0 and put a blanket of say 32* in the idle area.......put the timing light on the balancer, and adjust your Crank Trig BTDC number in the system parameters table in the XFI untill it matches........also if you ar running a crank trigger be sure the Inductive Delay is about 43uS..........this will ensure that the timing will stay the same as the rpm increases.........if that number is too low or too high you will loose or gain timing as you get into very high rpm.......i had this issue i maintained 33* untill 7100 or so then it started climbing up to 36 by 8000rpm+ (my buddy had engouh faith or ***** to stand under my hood with the light while i made the pull lol)........

any way.....keep tuning on that thing it should make some SERIOUS power NA all said and done.........if ya need any suggestions or have any questions shoot me a PM........chances are ive been down the road you are on already lol

Good Luck!!

 

This ^^^^^^

Not a smart idea! Natural selection at its best.


To the OP. Nice numbers!!!!!!!!!

 

I hate to post a negative comment but your buddy didn't have faith or *****. Putting it nicely as Tony said, that was just plain Not Smart. We had a car on the dyno and at WOT, the supercharger belt let go, it sliced the fender like a knife, this was a mustang with a steel fender not fiber glass, anyone near would of had their head whacked off. We also had a car break a strap on the dyno at wot, needles to say that was scary...

 

great #'s especially for a power robing drivetrain

 

Phil and quik95lt1, thanks for the feedback. Tremendous information. I will be pinging you both as I continue to tweak this combo.

Thanks Man. I appreciate that coming from you.

I am definitely not that brave. I have not seen a dyno operator that would ever allow this. Beyond hardcore.

Thank you. The parasitic loss in my combo is criminal.

 

i told him to back away once it started revving but apparently he felt compelled to stand there to 8000rpm lol.....

and OP no prob man lemme know......names Mike btw....

Good luck!!

 

Congrats, that sounds nasty. Just curious, what gears and are you still on the stock 8.5 rear?

 

Thanks Man. Still have the 8.5" rear. 4.10 gears.

 

That barge should GET IT!

 

^^David, saw your car in GMHTP mag

OP, when do you think you'll be able to hit the strip?

 

I'm thinking the same thing. It's a luxo-cruiser by the way. Still with factory air and all the amentities. Weighing in at a svelte 4250 lbs. Like you said, a barge

6-8 weeks. The air should be breathable down here by then. I like the set-up in your sig. Looks familiar minus 1/2 a ton