Timing Control other than BTC (Long)

[cpa]

I went to the dyno a week or so ago, but unfortunatley the printer was out of order so I can't post plots. At the end of the day, I believe that the BTC is truly hindering performance of my car (certainly not helping it).

Here's my current setup:
96 GSR
JR Crank Pulley Upgrade/BTC
Walbro GSS 342
Injen 3" short intake
Stock injectors
Fuel 50 idle/70 static/100+ WOT
Putting static around 60 results in less power and no effect on pinging
Timing - see below including BTC settings
DC 4-1 header
TYpe R B pipe with 2.5" straight through axle back section
Compression 210-212 all cylinders
Boost maxes out at about 8.5 - 9 PSI at around 7K and drops off to redline to around 7-7.5 PSI.

I really wish I could post the plots and hope to as soon as the shop gets a printer. More significant than the peak numbers for HP and TQ is the shape of the curves I saw, but I'll summarize:

First:
10 degrees/0.5 on BTC 91 Octane
197HP/ 152 TQ

Second:
16 degrees/1.0 on BTC 91 Octane, manually turning off BTC retard during run after about 5K RPM
206 HP, 165 TQ

Third:
16 degrees/no retard 50/50 91 Octane/103 Octane VPD race fuel
208 HP/170 TQ

The huge difference between these runs is the smoothness and shape of the power curves across the RPM range.

In the first run, there is a big dip at VTEC +/- 500 RPM around 4500 RPM and the curve is "lumpy" but not "pinging lumpy".

In the second run, the lower half of the curve is similar to the first, VTEC about the same, but after shutoff of the BTC the curve jumps dramatically and smoothes compared to the first run, nearing the third run with race fuel mix. The torque curve is 10 or more lb ft above run 1 from 5K up. (By the way, the curves for BTC at 10/0.5 vs BTC at 16/1.0 are about the same over the whole RPM band)

In the third run with 50/50 fuel, the entire curve was perfectly smooth and there is absolutely no dip anywhere including VTEC. Additionally, the torque curve is consistently substantially higher across the range, 10-20 lb ft or so (big differences at VTEC).

By the way, we also ran a Motec A/F meter and the car was consistently recording lambda readings between .84 and .88 or so if I recall. They weren't worried about my being lean based on the curves and the Motec readings.

My problem ever since installing the BTC at 6psi, and now at 8 psi is that I get audible pinging in the mid range around 4-5K RPM (hence the dyno experiment with turning off the BTC midway as I knew I could do while driving and the experiment with race gas)

As much as I would like to simply run the race fuel all the time and just not bother with anything, it's not realistic given how much I drive.

Given the performance that I know is in my car with an ability to simply tune more than I can now, I'm looking into options.

Since I'm OBDII, Hondata doesn't seem very attractive, because for a 2B installed and tuned including injectors, adapters, ECU, etc. it'll be $2,000 easy, it's not something that can be tuned at any time(like a 4B) and I'll have to give up my knock sensor (P28) or pay even more if I can manage to find a P72. But the shop is an authorized dealer and has tuned several Hondata's, although for turbos.

AEM's EMS so far seems fraught with "start-up" problems from the limited information I can find, no one has experience with it, cost would be similar all-in around $2,000 but is OBD II plug-in, tuneable and can datalog. I'm also not sure how the JR MAP/IAT tricks, etc. would have to modified.

The EFI PMS system seems interesting, has been around for some time, is plug in for OBD II, is tunable, can datalog and is more reasonably priced around $1,300 all-in with injectors and InterAcq. I'm unsure how the PMS would (or could) handle low vs high cam though or how much that would matter and I'm also not sure how the JR MAP/IAT tricks, etc. would have to modified.

I was also thinking that it might be interesting to be able to run water injection with the PMS tuning ability as well (i.e. if I upped the boost with say a stepper pulley and my JR crank pulley as well if hte PMS worked at 8 PSI [img]rolleyes.gif[/img] ), and my total cost would be the same as a Hondata 2B.

Or, I could throw a MAP mod on it for $180 and see if that solves my mid-range and move on, but if it doesn't then I have to get rid of that too along with the BTC.

I think that's enough - thoughts?

<font color="#a62a2a" size="1">[ March 15, 2002 01:12 PM: Message edited by: cpa ]</font>

[217gsr]

Hey CPA. I can't comment on any of the standalones, since I don't have one. But my recommendation is for the JR Map mod. Most people , including myself, who have had a Map mod in the past are extremely happy with it. With it on, you might even be able to run stock timing and little (to no) retard on your BTC.

Since we both live in San Diego, we're both dealing with the same ambient temperatures and humidity, so I would think that our cars would react (nearly) the same to most mods. The only thing is that your car is OBDII and mine is OBDI.

Well, just to perk your interest, my car is running a stepper pulley, boosting 9psi and maxing out near 11psi (on the gauge). My BTC is set to 1 click on most days and 0 clicks in the evenings. Static is at 57-58 psi. All on stock (16 deg) timing.

Check your personal mail box. . . I left you some mail.

<font color="#a62a2a" size="1">[ March 15, 2002 01:28 PM: Message edited by: 217gsr ]</font>

[CKim]

This isn't necessarily on-topic, but you said that your boost readings dropped off as your approached redline. Wouldn't think suggest that you have a slipping belt?

[bihari]

Sounds like the same problem I had with my Del Sol, I run an MSD 6AL with their Boost Timing control. I was always fiddling with the timing retard to keep it from pinging under partial throttle under boost. The JR Map Controller made a HUGE difference in my setup, I've been able to advance my timing back to 12-13 (was at about 10) & only have to dial in about 1/2 Degree /lb boost (used to be about 1deg/lb with 2-3deg less advance) and no more pinging under partial throttle.Better off-boost response, and MUCH better "driveability" transitioning between Vac/Boost. Your results may vary....but I think it was one of the better bangs-for-the-buck I did
for my 'Sol.

[cpa]

The drop off up top may very well be a slipping belt. But anyone that has looked at or adjusted the belt can't see making it any tighter or looser. I just recently replaced by JR alternator pulley as my original was worn after 20K miles. Now you see the potential thinking on the PMS and bigger stepper pulley [img]graemlins/devil.gif[/img]

[cpa]

Anybody have experience with Greddy's e-Manage piggyback? I called another shop today and it sounds like with Greddy's additional laptop software, you could completely control fuel and timing (16 RPM points) with 440 injectors, it also has VTEC control and installs like a VAFC? Also, much less than a standalone, about $900 for the e-Manage box with ignition timing control, software and 440 RC injectors? This sounds too good to be true?

[SuperTeg]

If you want the map mod I got a new/used one for $125 shipped. I paid $185 for it. I now have Hondata so I have no use for it.

[reddelsol]

I also second or third the map mod before trying anything fancier.

It significantly reduced the banging in my engine.

[klintman]

the hondata system is by far the most tried and tuned standalone , around here anyway . aem is somewhat new and from what ive heard has some poopy base maps . the hondata has a few negative aspects , but has proven itself with many people here . i wouldnt take it lightly that hondata has coustomer service second to none . the aem is plug and play can control vtec and has the potential to control nitrous or other solinoid actuated devices . buying the aem right now would make you a bit of a pioneer . it would almost certainly require dyno tuning . i dont know about the pms , but the hondata and aem should make any piggyback devices (fmu , tps mod , map mod , et cetra) obsolete . right now i planning on buying the aem ems when i go to 8psi later this year . sorry , long post with stuff you probally already know .

i will chime in and agree with the others about the map mod . i installed it at same time as the jrsc and run 16deg. btc timing free of detnation . i have the jr btc , but only dial in a few clicks on hot days to be safe .

<font color="#a62a2a" size="1">[ March 18, 2002 02:11 AM: Message edited by: klintman ]</font>