5500rpm
10.2 lbs boost
12.2:1afr
19deg
93 octane pump gas
85 deg weather

This is what my high end looks like from my data log. Stock 1993 5.0 short block, steel GT40 heads, Cam, huge intercooler etc read below.
Is it safer to tune in more timing leaner afr, or just bump it back up to 15lbs with "safe " settings?
Thanks for any input.

 

That to me looks like a great conservative tune. But what do I know

 

I personally think that looks sgreat. All though im sure every combintion is different. I wouldnt go any leaner than 12.5. I originally tuned mine to 12.2-12.5 and car made great power and ran great down the track. But everything I have read says 11.2-11.5 to be safe. So...I went back to the dyno. I richened it up and added timing to make the same power and it did not like that at the track at all. It laid down on the big end bad and didnt go as fast. I am:

10 to 1 comp.
10lbs of boost
92 octane
big intercooler
timing when leaner was timing locked at 34deg and pulling out 1.5 deg per lb of boost
timing when richer was/is timing locked at 34deg and pulling out 1 deg per lb of boost

I am in the preocess of switching to E-85 thanks to Brent Davis...so the tune will change.


Just be safe with the timing and you should be fine.

 

I would personally tune it to 11.8:1 or richer to be safe, i say that is to lean in my book.

 

If you were running 100octane then I would say thats a good tune but with pump fuel these days I would get the AFR down into the 11's to be safe. Not to mention a richer mixture will help with detonation.

 

I would also say that is to lean IMO. I would richen it up to LOW 11's but what do I know.

 

At what rpm did you start pulling timing with the leaner tune ?

 

I gather that he's running a BTM (boost retard) that pulls timing in relation to boost, not to RPM.

 

You are correct...for my set up that is. I guess i forgot to mention that.

 

I run 11.0-11.5 on my setup on pump 91 octane. I'd be scared of 12.2:1 a/f with pump gas.

 

I'm just careful with the timing. I made 700 rear wheel hp through an auto and ran 9.69 at 141mph on that tune. I also drive it on the street. still alive. Car weighs 3425lbs with me in it. 92 octane with Prochargers 1300hp intercooler.

 

You also have more cubic inch then me, so I guess I'm comparing apples to oranges. That a great et on pump gas!

 

Hes also runing a Chevy .

 

I didn't realize the cubic inches difference. Thanks man. I will admit I did retard the timing when at the track compared to the dyno numbers. I was also leaving at only 2000rpm and I shift it at 7000rpm. It was my first time out with the new set up and my first time out in 3 years. lol

 

Good point. But I am to new to the forum to knock other brands. lol Plus I do like all brands...of domestics.

 

^^^^^^^^ oh no he didn't
lol

 

My box is adjustable at what rpm I want to start pulling timing , THAT is the question I asked.

 

Well with my box it would be where ever I start pulling boost at. Honestly I haven't watched for where or when it starts.

 

Thanks , must be a diifrent box . I have a rpm dial and the retard also , I'm just not real sure at what rpm I want it to pull timing when it gets a boost signal.

 

I do have the timing knob to adjust how many deg per lb of boost comes out. The knob goes from 0-3 deg per lb of boost. But that is all I have to mess with. I am still learning this whole blower thing. But I love it!