Re: Maximum total timing Question: RE: Rick Andersons 756 hp 347ci motor in 5.0

C16 is slow burning stuff. I have seen cars with perfect tune for 93 octane lose 40 hp switching to c16 and not re-tuning.

I would say minimum 4 more degrees for something like the motor described above, and as Don and Shane said.... once cylinder pressure falls off (ie, torque starts to drop), providing IAT's stay similar, you can usually pound even more timing into it.... I do this on the dyno, and watch for the point of diminsihing returns...

My stock block car actually ran MORE timing in the top then factory, and AF ratio was a perfect "smile"..... I still get a chuckle out of "tuners" that brag about their "perfectly flat" 12:1 lol

Now, I recently did a 8.2:1 1600 hp engine, and we had 29 degrees in the top (8500 rpm), and 24 at peak torque on c16 at 30 psi, but IAT were only 80 degrees.... thats what it wanted, to be safe, I load em pretty hard, watch the shape of the curve, and look at the plugs here or there...

 

Re: Maximum total timing Question: RE: Rick Andersons 756 hp 347ci motor in 5.0

Oh, and the reason he was ramping it DOWN is cause his non intercooled supercharger was building boost with rpm, thus increasing IAT's with rpm on a massive scale...

 

Re: Maximum total timing Question: RE: Rick Andersons 756 hp 347ci motor in 5.0

:withu:

I think C16 burns about like diesel. LOL. And if you wanna be really wacky, go find some Elf Turbo 114(I think that's what it is). The F1 cars used to run it. Not sure if they still do or not. You'd freak out if you saw what a/f ratio you could run a turbo car at. Worked on a 1800hp twin turbo chevy a few years ago and we used it. 28 degrees of timing at peak torque with 24psi, 32 degrees at 7500rpm, with a 13:1 air fuel ratio. They dyno guy thought we'd lost our minds. On C16, we were running 3 degrees less timing, at 11:1 a/f ratio, and making over 100hp less.

 

Re: Maximum total timing Question: RE: Rick Andersons 756 hp 347ci motor in 5.0

Thanks TOma-- Thats what I was expecting to hear initiallly when i posted this. I am going to work on the susupension for now and stick with my 100 octane tune for now and when i get back to the dyno i will work on the tune with 116 and adding some timing and meth to see what it does.


F1 cars are running E85 now I believe.

 

Hey Lee,

With my old F cam, I ran 16 psi and 24* (by accident) on 100 unleaded and went 9.90's/135. Knowing it could handle that, I ran 22* at 18-20 psi. With 2 gallons of C16 mixed with about 6 gallons of 100, I ran 22* at 19 psi and went 139. I then added 2* after 5000 rpm and it picked up 2 mph.

I'll probably start out with 20*/100 octane on this solid roller cam and go from there. I'm not interested in finding the limit on pump gas, so the least octane I'll ever run is 100.

Just finished installing my Comp Pro Magnum rockers and took it for a drive. Should be at the track soon. Hope to see you and Don out there.

Rob

 

20 degrees on 100 is what i tuned with last year and had no problem. This year with 116 we couldnt keep traction above 6300 rpms on the dyno ( radial tires) so power readings stopped at 880 and fluttered up and down after that. trying to add timing or boost only made things worse Spinning) so we didnt try anything above 20 degrees. They were very cautious about going any higher even with traction so I decided to try to investigate what the max should be.

There are some guys from this board looking to go on the 22nd if weather permits-- you around that weekend?
Hopefully you have the rocker arm thing fixed for good now. I thought you got a new set of HS rockers? My proMagnums have been trouble free (hydro though).
Lee

 

I'm definetely interested in the 22nd. Where to? Byron? PM me the details.

Thanks,
Rob

 

I found out today that the 22nd is out for me-- so i went today! LOL - ran a 9.2 at 149!! (1.48 60ft- also a new best)Working on posting the videos soon. I need an antiroll bar BAD!! wait till you see the video! This car will go an 8 for sure when I can get it to go all the way down the track! of course i did drive the car to and from as usual!

Anyway-- Looks like I wont be back to a track til May and it will have to be byron b/c I wont pass tech anywhere else with my car.

 

Kick ass! Now I got to play catch up! What tire were you on?

Rob

 

28 x 10.5 slicks-stiff sidewall. I was also using my new skinny tires you introduced me to- they are great!! so thanks!

 

LOL, you got to love those slicks. It's so nice to be able to launch and not have to worry about tire spin. I run that same size slick with the standard sidewall. You leaving off the T-brake?

 

6 and 8 psi off the brake. it is stalling up to 3600 on the brake and stopping on the converter. i havent tried 2 stepping it yet or making any additional timing mods. takes 2 seconds for 6 psi and 2.5ish for 8 psi. then 1 second to get to 16 psi when i release the brake!

 

34 safe total then again i know guys running 36 total on 94 93 octane temperature plays a big roll in this as far as advancing timming.

 

Sorry for dragging up this old thread. My car has been sitting for the last year untouched out of frustration. My last time out I lifted the head and melted 2 pistons. I can't hear when the car detonates. I used to have a 302 with a S-trim 16 psi on pump gas at 24 Degrees of timing. Car ran great with no problems.
New combo is a 410 with a Z-trim and 19 Degrees of timing and 112 octane. Air temp is 240F ( which is much more than the S-trim). Fast DFI

So my question for all the guru's what is a safe timing table with hot air? Am I just asking to much? Is there a rule of thumb ?
I know every combo is different. I need a staring point. I'm tired of going nowhere fast.