28 replies to this topic

[RazerX]

I ended up getting mine at Murdock Industries for $27 for the pair.  Their part numbers A183011 FCM3011 / FBM30111, it is the Eaton part Todd referred to above.  

[Bench Racer]

127.8 hp at 6,735 rpm with 108.0 lb ft at 5,720 rpm.

 

Don't have the wherewithall to post the file/graph.

[Steve Scheifler]

With that engine, I could'a BEEN somebody!
Hard to not wonder what that might have been worth in countless races.

[Pat Ross]

From those numbers it looks like it could have been one of the old Sunbelt motors

[Steve Scheifler]

Maybe. The one I tested, then tore down for my exposé, never made that but it didn't have a properly tuned AFM. I think it was from ART but not rotated or tweaked to that engine.

[SaulSpeedwell]

1.  Exactly.  See also the threads about IAT on 1.6 vs. 1.8s and NBs.

2. Is your timing mark correct and your light correct?  And are you actually making more at 18, 17, 16, than at 15?  I ran 15 - a true mechanically verified 15 BTDC - and just left it. I think 90% of people that think 1-2 degrees of BTDC are giving repeatable timing gains are tricking themselves. 

3. I see cars that briefly hit 15-16:1 around 5K.  No big deal, especially since you'll never be there at WOT on the track?

4. Yes.

5. So grab the AFM with your hand and manually use it to get "perfect" AFR during the run, so that you can see what it is worth.  As I tell Steve, there is no trophy or Runoffs for perfect AFR

6. Get everything right, including the "2s" hiding in the brakes and the drivetrain.  What is your coastdown number?

7. E0, if you are making MORE from lower specific energy ethanol, something is wrong with your tune.  1.6s love the Sunoco GT260 (100 octane unleaded).  +1.5/1.5, generally.

8. Sure

9. The only thing you MIGHT be missing is whether you are spending your time and money where it will give you the best laptimes.  The key to me is getting the AFM open enough to not be a restrictor plate, turned so it isn't changing AFR on the track, and then get the AFR as good as it can be.  Getting it "perfect" isn't worth much.  Getting the rest of motor working, getting rid of drag, getting cold air in there are all more important.

[Jim Drago]

With that engine, I could'a BEEN somebody!
Hard to not wonder what that might have been worth in countless races.

Dynos are just like opinions.. And you know what they say about opinions.. Those numbers ( good or bad) have no relevance less compared to known good car(s) on same dyno ( preferably the same day). We have all seen some cars that are rocket fast at 120 Hp and not so much at 130. 

[Steve Scheifler]

Dynos are just like opinions.. And you know what they say about opinions.. Those numbers ( good or bad) have no relevance less compared to known good car(s) on same dyno ( preferably the same day). We have all seen some cars that are rocket fast at 120 Hp and not so much at 130.

Yea, I know all about dyno variances, but as you point out some engines really are stronger than others, whatever the reason. Automotively, I grew up with a guy who's family had an import dealership and he learned quickly to choose his own demo by sampling a bunch. My point was only that I know our engines are not special (unless they ALL are), and I really do sometimes wonder how much difference it would make to have that "peach". I have some indication because for my one trip to the Sprints, after Q1 I was P2 (to you, by a bunch as I recall) without a draft partner but got pushed off and bent the suspension. Got it close but still lost camber and without scales etc. did a lot of guessing. After Q2 I was the only one near the front to not go faster and dropped to P4 replaced by someone who pulled a draft lap with you. In (STUPID) desperation to compensate for handling I decided to try a riskier tune expecting an extra couple ponies but got it wrong. The loss of a few HP made me look like I was in the wrong class at the start, I think I was 10th within a lap and finished there thanks to some attrition.

So yea, I sometimes think what that weekend might have been like with a "top" engine and a straight suspension. 95% chance I'd have lost positions due to inconsistency but at least that's me and I'd know it, not leaving the big unanswered question.

[MrGene]

How does the afm affect the afr at 6-7 k? Probably a dumb question  but I'm trying to figure out how the afm works?