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Timing Adjustments


Quick How To

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From: Lee Chang (l2chang@uci.edu)
It's a lot easier to do this with another person, so grab a friend before you start. Before you advance the timing on an Integra you need to first put a jumper in the passenger side socket or you'll get an inaccurate reading. To get to the socket, remove the kick panel under the passenger side dash(there should be two tabs holding it on). Then reach up and grab pull out the big green socket, which is actually a socket cover holding two blue sockets. Pull off the cover and put a paper clip or thin wire into the two holed socket to form a circuit. If you did this right, you should see the check engine light stay on when the car is running. Hook up your timing gun to the rubber coil on the distributer cap and the wire for plug #1.

Now, to find the timing marks, look on the pulley on the lower driver side of the engine. You should be able see to two marks on the belt with a timing gun, a red one and a white one on top. To find the actual reading, zero your gun and look to see where the red mark falls against the engine block. This, duh, is your zero-mark. Remember where this is. If you have small enough hands, reach down and mark it with a pencil Now play with the adjustment on the gun until the white mark falls onto the "zero-mark". The reading on the gun should say 16 BTDC +/- 2 degrees which is factory, mine said 15 BTDC. Set the gun at 18 BTDC and loosen the three bolts(careful it might be hot!) on the ditributor and move it counter-clockwise until the white mark hits the "zero-mark". This is where that friend comes in handy, one to do the moving and one to do the looking. When it's set, tighten everything back up and shut the motor off before you remove the jumper.

From: Somchanok Prathnadi (prat@lan.nsc.com)

                              |=Pointer
                              |
                              V


                              B   R   B           White= TDC
                 ____________________________________
                              I   I   I           I
                 ____________________________________

     Right ? ------>          18  16  14          0
                                 ==  ==  ==
                                       ^
                                       |_____ was this

  Mine is like this with connector shorted.

Advanced Timing Information

From: Shawn Church (mailto:Shawn_P_Church@ccm.ch.intel.com)
I have a tip for you (and other 3rd gen owners) on more performance. Advance your timing! This is an obvious modification, but one many people don't do because they don't have timing lights. A timing light is nice (people can email me if they want detailed instructions from the repair manual), but you don't need it.
 

Timing is advanced by rotating the distributor. The distributor is held in place by 3 bolts. You will need a socket and extension for the lower two, and a box end wrench for the top one (can't get a socket on there). Do this while the engine still retains a little heat from driving as it will make it easier to loosen the bolts. Wait a while though or you'll get burned. O.k., you'll note that there is a mark on the top bracket that connects the distributor to the block. If there isn't one, make on. This is your reference so you know what the original timing is. Get a fine tip marker and make several similar marks along the bracket (closely spaced) on the left side of the original one (looking from the passenger side). Now loosen up the distributor and rotate it counterclockwise to the first mark. Tighten it up, warm up the engine and go drive it up a grade in as high a gear as possible without lugging. Turn the air on too. If it pings, and you will hear it, you've go too much advance. The knock sensor will pull back the timing, but you will still pick up a bit of ping. If it didn't ping, go back and rotate it another mark and so on till you get ping, then back it off one mark. By testing it at full load, you can ensure that at no other time will you have to worry about the engine pinging.

Note that if you do this in winter, you may need to adjust it again in the summer. I did mine on a 90 degree day so I'm not worried. I gained 2 mpg and better low RPM power. 5th pulls a lot nicer on the freeway. I advanced mine about half of the additional adjustment between the original mark and max advance. Tim Kelley advanced his all the way for max power on the dyno. BTW, by advancing your timing, you're doing half of what an aftermarket chip will do, for free!

Okay, for those of you thinking: "Wait a minute, what about the knock sensor and the ability of the stock computer to retard timing?" After further discussion with Shawn, we think that the '94+ Integras uses the distributor timing as a base. The computer then works off of this base timing, adjusting the curve of the timing depending on load conditions. Henry advanced his timing and he saw very noticeable improvements with his modified GS-R. Blipping the throttle on heal-toe downshifts was faster with the engine reving to the desired speed much faster. We both advanced it to halfway of the maximum amount of timing. You probably don't want to go much further than this because advancing the timing will cause you problems if you don't run super unleaded. Be careful and don't go overboard with it.

From: Adam Glass (aglass@delphi.com)
Advancing your timing too far can lead to nice round holes in your pistons and/or blown head gaskets. And you (and your knock sensor) won't necessarily hear the increased pressure and temperatures if the timing is just a little too far advanced. I'm not saying that advancing timing WILL cause problems, but I'd caution people to think twice about advancing it past max spec. The spec is something like x degrees BTDC +/- y degrees -- in other words, be very careful about advancing it past x+y degrees BTDC.
These are wise words of caution from Adam. After some testing we did, we actually found that the good timing advance point was just a little over +2 advanced which is on the spec: 16 +/- 2 BTDC at 750 +/- 50 rpm with all electrical systems off and shift lever in neutral.

From: Shawn Church After going out and checking the distibutor, I've advanced mine about 6mm past the factory reference mark. I went as far as 12mm and got ping. I was running maybe 7 or 8, but reduced it because I was doing some dyno runs on the car. Tuan actually used a timing light on his, so maybe he can tell you how far 2 degrees is. Of course, this will vary from car to car. Another owner has advanced his as far as it will go (mechanically), but his car is heavily modified.
For reference, ping will occur under heavy load and sound like a little tapping, rattling or pinging from under the hood. I find it easy to hear when the windows are closed to tone down the tire and wind noise. On your car, you shouldn't hear more than a ping or two at a time as the computer will pull back your timing. Theoretically, I guess you could advance your timing all the way and let the computer keep you at the bleeding edge. However, since we don't know how much the computer retards timing, you might actually be running less advance that way. Example: advance timing 3 degrees, no ping. Advance 4 degrees, get ping, computer pulls back timing 2 degrees, net 2 degrees advance.
Be sure to read the latest update on the page as well. 18 degrees is about as far as you want to go (I'm still not sure how Tim Kelley went to full mechanical advance).
If it's that cold, you should definitely be able to advance quite a bit. I've really been wanting to try some race gas (105-110 octane) with full advance on a cold night, then again, who knows what the side effects might be :-).

From: LKY 12/11/95
when I advance my ignition timing using a timing gun, I found that the factory set the ignition timing below the red mark (red mark = 16 btdc). I also found the same thing on my friend's GSR. I think you should advance your timing at least to the red mark. I'm sure you can feel that the engine is more easy to rev up.

From: Shawn Church
Xmas morning the first thing I did was go warm up my car and check the timing. Turns out I had it set at about 16.5 for the dyno run. I set it back to the original mark from the factory and it read about 14.5-15 BTDC - actually below the median spec! I then checked it at the mark where I got pinging, about 18.5 to 19 - no wonder! I then proceeded to set it to 18 on the nose and its been wonderful ever since, no pinging, free revving, etc.

From: Gary Shrieves (gshrieve@vt.edu) 01/12/96
Not to beat the issue to death, but since an Acura lacks timing graduations like that of most American cars, make your own template! Measure the diameter of your crankshaft pulley with a ruler. On a piece of paper, use a compass to draw a circle of that diameter. Mark a line on the top of the circle. This is 0 or 16 deg, either way. Then, take a protractor and measure off the degrees increasing in a counterclockwise direction (this will be advanced). Now you will have an exact template in scale of timing marks.

Additionally, when adjusting the timing, don't forget to put a jumper in the socket under the passenger side dash! If not, it will be inaccurate. 



 

Advanced Timing Dyno Results

by Shawn Church

Thanks to Chris, Jeff and Tony of Pro-Dyno for their assistance. Pro-Dyno can be reached at (602) 967-5550.

Test Conditions

The first two dyno sessions were performed in the winter months with dry cool air. Testing conditions were in the high 70s, low 80s. The latest test session was performed with air nearing 90 ambient in a swamp cooled warehouse structure (meaning high humidity). Engine operating temp was probably higher as well and fans may have been in operation more often on the latest test. Winter tests were also performed on reformulated gasoline which may have impacted results. Conventional wisdom says that reformulated gas contains less energy, but may burn more efficiently. Despite SAE correction factors, it is difficult to compare runs separated by such a large time period and divergent weather conditions (this assertion is supported by both Pro-Dyno and the documentation from Dynojet). 

Condition of Car

The first test was performed with the car in need of a valve adjustment. The second session was performed almost immediately after a valve adjustment. This could certainly account for some differential in power. Regardless, the tests show that headers probably do not provide a significant boost without a freer flowing exhaust system. The third session was performed after an air conditioning compressor replacement, 6000 miles since the last valve adjustment, with a malfunctioning O2 sensor. The O2 sensor should not affect WOT readings, but the car will be retested to verify. 

Modifications

The first test was performed with the DC ceramic headers and an open element conical K&N on a DC bracket and pipe (connected to stock intake tubing). The second test was performed with the stock headers after the DC unit developed a crack. The air filter remained in place, but the timing was bumped significantly over the 15 BTDC run on the first test (this combined with the valve adjustment allowed the stock header test to produce more power than the test with headers). The third test used the rewelded/recoated DC headers, a Dynomax custom cat back with 2.5" piping and a resonator, and a K&N filter supported by the bottom half of the stock airbox after the mounting point for the DC bracket broke. This change in the air filter configuration (in addition to being somewhat dirtier after a previous ram air experiment) is predicted to have affected intake efficiency somewhat. Timing was also reset to just under 18 BTDC to compensate for the hot summer weather here in AZ (avg daytime temp in the 110 range). 

Dyno Results



Conclusions

Even small variations in weather, timing, valve clearances, etc. can affect the amount of power produced. Therefore, when comparing runs separated by large amounts of time, large differentials in weather conditions, etc., the results must be considered carefully. The most valid comparison are garnered from back to back runs after modifications. What this tells us is that the Acura Integra VTEC motor responds very well to timing adjustments being able to gain significant hp on top, while losing a little in the midrange before the cam profile switch. While there is no standard data for this car, other test results suggest that the addition of a free flow air filter also yields significant returns.

The results also indicate that despite strong seat of the pants feel, headers do little to benefit WOT performance (part throttle may be/is improved) when used without a free flowing exhaust. The results do clearly show, however, that a free flowing exhaust, combined with headers, can add significant benefits, especially in the midrange area. The results also show that the gains from an exhaust taper off after the secondaries on the motor open up. It is the belief of this tester that VTEC motor is designed to run leaner once the secondaries open and therefore is not getting enough fuel to compensate for the additional air flow the modifications provide. This additional air flow leans out the midrange mixture enough to gain significant power, but is too lean for the range above 6000 rpm.

It is also the opinion of this tester that the performance of the latest modifications will be enhanced by a timing boost at least as much as the previous configuration was. This would tend to indicate a slight softening in the torque curve from 3000-4000 rpm while picking up significant low end (sub 3000) and high end (above 5000 power). Predictions for a power peak of 156-157 hp and a torque peak of 125 lb-ft are reasonable. A Dinan chip will be tried to richen up the top end mixture and see if power gains are realized. 


Summary and Recommendations

The Acura Integra DOHC motors (in this case the VTEC model) provide an excellent basis for modification. The typical VTEC motor produces appx 140-142 hp at the wheels factory stock (non VTEC produce appx 118). For appx $600-700 (this owner spent appx $675 without shipping) the VTEC motor can be enhanced to produce over 10% more hp and, more significantly, 15% more torque with an incredible midrange boost. An additional $300 for a throttle body and adjustable fuel pressure regulator could yield noticeably more (this tester expects 8-10 hp at the wheels). This is all without opening the motor, changing cams or computers, etc. In most cases, the car will remain smog legal as well. Estimated maximum crank hp for these minor mods is 195-200 hp and as much as 150 lb-ft of torque - essentially the numbers of a Prelude VTEC in a lighter package for signficantly fewer dollars.

It remains to be seen how much more power and torque an ignition system, adjustable cam sprockets, and a ported and polished manifold can add. It should be noted, however, that these mods will probably provide less hp for more money - the law of diminishing returns. The first set of modifications offers 25-30 hp for less than $1000. The last three will cost $1500-2000 assuming the owner can disassemble the intake manifold and install cam sprockets (there is a far greater consequence for mistakes here than in installing the first set of mods). It is unlikely that the car will gain much more than the 25-30 hp picked up originally (but it is still worthwhile). If you have a non-VTEC car, cams would be an excellent first step after the bolt on mods - these will typically return about 10-12 hp at the wheels. 


Fearless Recommendations

  1. Advance timing to the factory maximum - 18 degrees BTDC. Before you go racing, experiment with more advance to determine how far you can go before detonation. My car runs well at 21 BTDC which is worth about 0.1 sec in the quarter mile. I do not run this on the street however.
  2. Get a high flow air filter - K&N seems to work very well and is very economical. You can buy a K&N system from someone, or just get the larget filter you can fit and have a metal shop fabricate a bracket and connector pipe. If you don't want to replace the whole intake tube, you shouldn't have to spend more than $100 (probably a lot less!).
  3. Open up the exhaust - whether it's with a Trust BL or a custom system, this is a must. I am very happy with my 2.5", mid pipe resonator, Dynomax Super Turbo system - it sounds good, looks good, and works well. At a reputable shop, you should be able to obtain a nice system for under $200 depending upon options. I spent $250 for mine which included the piping, muffler, fabrication, installation, and a very nice 4" tip - oh yes, I also got lots of dyno time to go with it (normally a $65 option). While a Trust BL may look a little better, even sound a little better, I'm on a budget and can use the extra $250 elsewhere.
  4. Get some headers - if you're going to open up the exhaust, you might as well get rid of as much restriction as possible. You will also save some weight - about 12-14 lbs by my measurement. These will also halp maximize the exhaust. Cost - less than $350
  5. Get a throttle body and port match the intake manifold. This follows the same "open everything up" principle. Cost - $150 + $50 for the port matching.
  6. Get everything else, although I might recommend experimenting with an adjustable fuel pressure regulator first if you have access to a dyno. With proper tuning, timing and pressure adjustments will do most of what a computer does - at least at full throttle.