Hey guys, I'm kinda stuck in a hard tuning place. I'm going to take an efi tuning class in acouple of months , but it does me no good currently. lol The person who I had tune my car HP twin 57mm SOHC 4.6L left the tune very soft from what I'm able to tell.

The motor is built to make as much power as possible, I can't remember comp names, but I know he built a clone of my motor to run in his 10.5 outlaw car.

From what I remember it is
8.5cp,
steel crank,
billit rods,
stanless rings,
dish pistons (not sure cc)
think I remember him saying something about MR2 heads? I have no clue, but fully p/p, cnc, big valve PI 4.6 heads
cams are a crane regrind of the stocks, have spec sheet somewhere, but they are blower grind. from old combo F-2
83lb inj.
bullit intake, / testing new Logan intake
bbk 57mm tb
DIS-4
FAST
if I missed something just let me know

The quesions I'm after, are timing? and my inj. d/c, but most of all the main operation and if anything looks out of place. I'm attaching a gct and log files if you would like look them over and suggest anything that you see could be changed or improved upon. The motor is run on 116 octane and looking for every last bit of boost that these lil 57's will make.

On my street tune that I run in the car (93 octn) I run 25* timing out of boost and the motor is right snappy like it should respond, I pull out .5-1 timing vs boost and bingo I've got 18* at 14#'s, car is right peppy no knocking plugs are great looking.

When I went to have the car tuned the tuner wanted me to have 116 in the car, he was very slack and not to speedy about getting the car tuned. He basiclly took all day to make acouple of pulls, and included is the gct that I ended up with from him. The car did put down 68x something to the tires on 14#'s but knowing what I run on 93 octn and seeing the timing difference that he has in the 116 makes me wonder.

With the 116 in the car it's very sluggish compaired to the 93 octn at the same timing lvl. So that alone tells me that more timing can be added, I just don'e know how much more. What is the timing difference in octn ratings degree whise, or how much more timing would a particular octane allow you to run, say the 93@ 25*, and the 116@40*? Or what is the whole purpose of the higher octane besides being another $8 outta pocket lol.

I know the timing on top end you want to stay around 20*+/- but I'm would think more timing could be added down low?

Feel free to suggest all that you will, thanks for your time

 

Here is a vid of the car testing a new Logan intake. That is the second log file that is there. foot brake 626@111

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After a quick look over,your inj dc is pretty well topped out.This can be one or more thing.I would think that your injectors at 80# or so are not too small.What type of fuel pump are you running? and is your fuel pressure regualtor referencing boost at a 1to 1 rate?
As far as timing,I was bit confused,Are you running some sort of timing retard?
Also you may try to fatten up the a/f. some car like to run a bit fatter than others

 

The fuel pump is an aeromotive eliminator pump with regulator on a 1:1 with boost. -10 feed line split to -8 for rail then regulator -6 back to tank.fp set at 45psi base.

for timing I'm trying to get a feel for what I will safely be able to add to benifet from the 116, into the fast timing maps., under 99kpa, above 119kpa instead of the 25* I run for 93 octne to give it some pep back

ok thanks I will try more fuel

 

25* sounds a little high for pump gas and 14#'s of boost. I would have guessed somewhere in the 22-23 range on pump. I would say if you arent getting any detonation on 25* and pump then you should be able to add 3-5* to 116 and still be allright. Best bet is to make a pull and listen for detonation, if you hear any turn it back down some.

Also with the 116, did yall adjust the tune in the fuel table or what changes were made?

With my current setup I am running 20* with 10 psi of boost on pump gas, but my compression is 9.5:1.

Jeremy

 

no no I'm sorry ls1killr on the street I run 25* under 99kpa and I pull it out at a .5-1* per psi so that I end up at 18* with 14psi of boost sorry I didn't clarify. The motor is solid at 18* with no knocking, pinging, detonation, and plugs look great. The timing curve for the street tune is soft, which is fine by me cuz I'd reather blow it up trying to go fast at the track than laying into it from a red light or something.

When the guy tuned the car for the 116 I was looking over his tune-up for 116 vs my tune-up for 93, and the only thing it seems he did was add 2-3* in the 3000-4500rpm 119-197kpa range (which I could of done on street tune but didn't want to.) For the VE table all he really did was +/- the correction % for that day. Is it that the 116 is only good for about 2-3* more timing than 93? Or was he just creeping up on it very very slowly?

 

You should be able to add more timing in than that. My brother just setup a race tune the other day with his AEM on 110 and he went from 18*(street tune) to 24* on the race tune with no signs of detonation. I would imagine you could get away with at least that much or maybe a little more.

Jeremy

 

ok thanks, now I have something I can work with. gonna start to inch my way there. what about under 99kpa what would be something that I could safly put in the tables for no boost on the 116?

 

In my idle regions(less than 99kpa) I am running about 30* timing(brother is running 34*)

Here is a screen shot of my spark table, I know it may not be perfect but it gives you an idea.

Jeremy

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Below 99kpa you can run an a$$load of timing. We regularly run 40 degrees at idle up through 99kpa and then pull 2 degrees per row going up on 116. C16 burns so slow you have to run a lot of ignition advance to keep it from loading up.

 

ok thanks for the pointers guys , I'm going to write a timing curve on the safe side and give it a shoot tomorrow night