Acceleration Enrichment

[99ssei]

Having some part throttle knock and looking to increase the acceleration enrichment. Which tables are used to make these increases? The tables I want to know more about are:

AE vs. TPS Max Delta
AE Modifier vs. Speed
AE vs. ECT vs. ERT - In Gear

For each table, does an increase raise AE or lower? Which is preferred to modify?

[MNR-0]

If you are truly getting ping then back off the timing a bit. If you are at part throttle, you want to be around stoich (and not under boost). More fuel at light loads can actualy send you backwards both for economy and power

[99ssei]

Thanks, but that doesn't answer my question.

[e85grandprix]

What you want is to do what he said above, because adding fuel won't solve your problem, hence why you got the answer he gave you.

[99ssei]

I think I found most of my answers here:

http://www.turbotweak.com/AE1.pdf

And here:

http://www.thirdgen.org/techboard/di...ients-map.html

[MNR-0]

Well I haven't seen those tables on anythign from OZ. But unless you bring something new to the table, I still stand behind what I said

If you are experiencing ping at part throttle how can AE be of any value? Aren't you at close to steady state anyhow?

If you stab the throttle and want a pump shot you do it either by the TPS VE multiplier at low engine speeds or correclty dialling in your VE map at those loads and engine speeds (done via steady state tuning at low engine speed)

Anyway, since you posted for a response, you got one. Would you mind also posting your results?

[99ssei]

I will go back and check the VE table, however, I was under the assumption the VE table is only referenced when the MAF fails or used in a SD system. Is that not true?

Also, where in HPT can I find the TPS VE multiplier at low engine speeds? I'm not getting the desired output when I stab the throttle. From a stand still, >50% TPS = 10+*KR. Roll into the throttle and past 3K 100% TPS = 0*KR @ 16* and O2's 940-950 (wideband arriving today hopefully being installed this weekend). LTFT's are +/- 1% and locks in at 0 at .92 g/cyl

[MNR-0]

If you want absolute predictive control disable your MAF and go speed density. Its only good for steady state anyhow.

You need to upgrade your OS to support 1 bar speed density enhanced (2 more credits I think) and there you are. Or. if your are runnign MAF, 1 bar MAF enhanced

[murphinator]

If you want absolute predictive control disable your MAF and go speed density. Its only good for steady state anyhow.

You need to upgrade your OS to support 1 bar speed density enhanced (2 more credits I think) and there you are. Or. if your are runnign MAF, 1 bar MAF enhanced

I have never heard of HPT offering any type of custom OS on 3800 vehicles ? and if they did wouldnt a 1 bar sd only be useful for normally aspirated not SC ?

[MMGT1]

1 bar = 14.5psi does it not guys? I like Murphinators question here though. I'd like to know the real scoop on this one, how Bar relates to boost in a car as compared to the "real world". Atmosphere is 14.7psi, and I have read before that a 1 bar map can read a couple of pounds of boost... which makes no sence to me at all. Physics tells me that 1 bar is WOT in a NA engine, so how can you pass that with a 1 bar map?

[passingpower]

Let me take a stab at that one. Almost every automotive component is an engineering compromise. Performance/economy etc. Rarely will you have a "perfect" induction system; There will always be restrictions. Accordingly, there will be a pressure drop meaning the plenum will always be under a certain ammount of vacuum. In practical terms WOT = -1 psi maybe -2 psi with a restrictive stock intake. In the end, one or two pounds of forced induction covers what four barrel progressive carb and tuned long runner manifold along with two oversized intake valves, ram scoops with dual oil/gauze filters strive to accomplish. Just my musings on the topic. As far as 14.5psi vs 14.7psi: Yes. 14.7psi is one ATM at sea level. The pressure drops linearly as altitude increases. Since relatively few vehicles operate at or under sea level, (not being a smart-ass on that, I'm referring to the land surrounding the Dead Sea) engineers had to settle on some value less than 14.7. Doubtless, many studies were done to determine that 14.5 psi would cover most operating environments. That, and it's an easy, round-ish number to calculate with.