Dyno tuning

[roccit_53 at scirocco.cs.uoguelph.ca (C Boyko)]

On 7:07 am 08/13/06 "Dan Bubb" <jdbubb@verizon.net> wrote:
> LONG, LONG, LONG!!
>


GOOD GOOD GOOD!!!! Damn, porn in the morning, I'm LOVING it!!!!!!

Awesome report, I LOVE hearing them run on the dyno, it's been far too
long. Interesting about the delay in the WB, and about the tuning process/
results.  That car is awesome, I really liked the way it felt on the road,
just plain old power whenever you asked. I'm sure it's even better now!!!
And those numbers, damn, you build fine machinery. Can't wait to see what
you build for yourself!

Yeah, so thanks for that post, just what the doctor ordered.

Cathy, stuck babysitting 100+ "young ?adults?" for a pig roast last
night/enjoying poison ivy on the face :(



> Finally decided that it was time to stop farting around and put the
> nephew's (Mike) car on a dyno and actually tune it.
>
> Couple interesting things came out of this.
> The first was that we wasted about 5 runs trying to fix the engine
> running lean at low RPM boost. We kept richening up the lean area at
> 3500 and below and kept seeing the 4500 RPM range richening up with
> no change at 3500. Well there's the length of the exhaust pipe and
> there's about 10 ft of tubing to the dyno's WB and that was
> essentially delaying the signal about 1000 RPM. 5 wasted runs
> figuring out the dyno WB had a significant delay.
>
> Once up into the higher RPM ranges the dyno WB was showing leaner
> running than Mike's Innovate LC-1 WB by about .5 AFR so we used that
> as calibration which was the point of using the dyno WB in the first
> place. So, basically we went back to Mike's original map that had a
> very consistent AFR from his tuning efforts, richened the whole boost
> portion of the map by .5 AFR and ditched the dyno WB. So, something
> to keep in mind and the most likely reason that dyno runs always seem
> to start off lean.
>
> The second thing was that despite all the effing around with AFR in
> the 12.5 to 13.5 range, we saw no significant difference in power.
> Richening it up did stop the engine from pinging when boost first
> came in though. http://i9.photobucket.com/albums/a95/jdbubb/86%20JH%20
> Turbo/scan0001.jpg
> That was about as far as we could go with fuel tuning. I figured we
> were about done cause when we started we had some pinging.
>
> Mike's using a Cheapass (R) ball and spring boost controller that we
> cobbled up (works just as good as a Forge manual boost controller
> though!) and it allows boost to initially rise to 13psi, then brings
> it back to 10 psi and maintains that fairly well. That's why there's
> a big hump in the torque curve at 3800. That's also where we had some
> pinging.
>
> So, the next thing to try was spark advance. Again, at 3800 and 13
> psi we were already, apparently, on the limit. So we progressively
> added more advance at higher RPM. 1 degree at 4200, 2 at 4800-6200
> and 3 at 7000. We did this several times and the progression can be
> seen here: http://i9.photobucket.com/albums/a95/jdbubb/86%20JH%20Turbo
> /scan0003.jpg
> Advance at 3600 and below was unchanged, but the engine definitely
> liked more advance at higher RPM and we were able to bring the high
> RPM torque up. Advance at 6200 went from 17 to 23 degrees by the time
> we started pinging again.
>
> Lastly we tried increasing boost. We had essentially been tuning at
> 160 kpa. Increasing boost only 1.5 psi brought fairly significant
> pinging (BTW, you should hear pinging on the dyno. It's almost like
> the engine's sneezing, but it's a really hard mechanical sneeze ;^)
> so we started bringing the advance in the 190 kpa range down to
> compensate. In the end we ended up with virtually the same power we
> had at 10 psi boost since we had to pull so much advance out. So,
> that was that. Back to 10 psi boost and call it a day.
>
> Also of interest is watching an engine on the dyno. They move around
> a LOT!! Towards the end of the day we could almost tell how well the
> run had gone just by watching the engine position. No top end, you
> could see it relaxing in the mounts! Last run, it was leaned back all
> through the run. ;^) First and last run comparison:
> http://i9.photobucket.com/albums/a95/jdbubb/86%20JH%20Turbo/scan.jpg
>
> Eighteen runs, $200, we'd learned a few things, got a shitload of
> data and picked up 13 peak hp with an even bigger difference above
> 5400. 186whp @ 5400 on 10 psi boost and 220 lb-ft @ 3800. Maybe not
> huge numbers but this is an incredibly streetable turbo. Where before
> it was all about using the midrange and shifting early, now it's
> still pulling strong at 6500. ;^) Imagine Mike sneaking up on sooo
> many unsuspecting suckers driving this: http://i9.photobucket.com/albu
> ms/a95/jdbubb/86%20JH%20Turbo/100_0759.jpg
> What a kick in the butt to drive!!
>
> What's next? Mike's engine apparently isn't very detonation
> resistant. Gotta get around that and run some more boost.
>
> One of these days I'll have more power than my nephew! :^(
>
> Dan
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