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CTSC High Boost and AEM, where's the power?

Joined
8 November 2003
Messages
2,412
Location
Portland OR
I got all the toys installed, high boost pulley, new belt, RC 550 injectors, AEM 1:1 FPR, AEM dual wide band, AEM ECU, Walbro 255 pump. Sean @ Torque Freaks is doing the tune, I think he is about as good as it gets for the AEM. The car is smooth, runs out well but it is only making 318 RWHP! Torque is flat 220-225 '/lb., peak @ 6500, A/F is flat11.8-12 across the range. Max boost is 7 lb. falling to 5.5 lb @ 8000. Does not increase power with timing or fuel changes.

Car has DC sport headers, Comptech exhaust, K&N filter and Comptech air box, Dali super sucker carbon cone so things should be pretty free breathing, I do still have the CATs. Compression is at 215-220 lb. for all cylinder, good for 108K miles.

Where's the power? They are going to do a pull with open headers just to see if the CATs are plugged, other than that, where to look? One cam off one tooth? :confused: :confused: :confused:
 
Sounds low to me! I know romeos white car dyno'd at 360 rwhp with a similar setup but no AEM. Of you want a car with more power, I'll trade you. :)
 
You are unfortunately really low. Have you checked your belt for slippage. I wonder about your boost dropping so far down at high RPM. You might want to call Michael at Autowave 714-841-2433 about your numbers. He has done a great job on the tunes of my car and Racerxling. We are both making ~370 rwhp and 280ft-lbs on the Dyno Dynamics.

Rod
 
If I were troubleshooting this car, I would check the synch between the AEM timing map, and the engines timing input. If it was not done with an actual plug wire, it is probabally way off. The service loop is useless for this procedure.

I have seen this with many AEM installs.

HTH,
MB
 
NSXTech said:
If I were troubleshooting this car, I would check the synch between the AEM timing map, and the engines timing input. If it was not done with an actual plug wire, it is probabally way off. The service loop is useless for this procedure.

I have seen this with many AEM installs.

HTH,
MB
That was supposed to be the first thing Sean did beacuse I don't own a timing light any more and just guessed when I did the original AEM setup. I will call and confirm tomorrow how the timing was set.

If the synch was off, would it make the whole range off by a certain amoun, IE, the AEM thinks 20 degrees advanced is really 12 degrees advanced, so the whole range is off by 8 degrees and the numbers don't make any sense. Or is it an issue that just nothing works right. Sean did the power tune by advancing timing till the engine would not make any more power and the knock sensor became more 'active', then backed off to the point where max power was made.
 
HotRod said:
You are unfortunately really low. Have you checked your belt for slippage. I wonder about your boost dropping so far down at high RPM. You might want to call Michael at Autowave 714-841-2433 about your numbers. He has done a great job on the tunes of my car and Racerxling. We are both making ~370 rwhp and 280ft-lbs on the Dyno Dynamics.

Rod
I don't think the boost numbers are out of line, have not heard of anyone pushing more than 7 1/2 lb. of measured boost. The 7 lb. number was after the new belt broke in and was re-tightened. My low boost never made more than 5 lb on a good day :wink: with a drop off to 4 1/2 lb. at 8000. Your numbers are what I am hoping for, 360 RWHP seems like the minimum I should be getting.
 
I have a 3" pulley that would work for the Comptech SC I have a larger Whipple SC thats who makes them for Comptech. I was running 15PSI with this and it should get the smaller comptech units to 12 PSI or so. I'm changing to a new set off pulley's with hopes of getting up around 19 to 21 PSI.
 
titaniumdave said:
If the synch was off, would it make the whole range off by a certain amoun, IE, the AEM thinks 20 degrees advanced is really 12 degrees advanced, so the whole range is off by 8 degrees and the numbers don't make any sense. Or is it an issue that just nothing works right. Sean did the power tune by advancing timing till the engine would not make any more power and the knock sensor became more 'active', then backed off to the point where max power was made.

If the synch is off 8 degrees, the timing will be 8 degrees less, or more :eek: than the map indicates in every cell it reads. It does not affest the map itself, but rather where the whole map 'thinks' it is relative to the crank position. IOW, the synch tells the ecu what the crank position is actually is, because the ecu has have a to zero pont (or in this case a 12 degree point) in order to set timing across the whole range.

Going to max power increase then backing off a little is a way to tune, but not a method I suscribe to. IMO, it is better to know exactly what timing you are at, so that you can put in max safe advance for max boost/rpm and know you are at a safe limit.

IMO, the whole concept of tuning for power, means taking chances you might bot otherwise take if you did the math and set safe limits. If you do this, and you are missing power, something needs to be done to locate and fix that.

JMHO,
MB
 
Thanks Mark,
I will post when I have more info.
 
Read the plugs. They'll tell you what the motor wants, not what you think it needs.
 
Mark911 said:
Read the plugs. They'll tell you what the motor wants, not what you think it needs.
Old plugs looked OK, just a little carbon build up which is consitant with the rich condition the car has been run in. They have not gotten it back on the dyno yet, hopefully this afternoon.
 
titaniumdave said:
Old plugs looked OK, just a little carbon build up which is consitant with the rich condition the car has been run in. They have not gotten it back on the dyno yet, hopefully this afternoon.

Can't use old plugs. Put a new plug in the most convenient hole (hopefully right before a dyno run) and do a good pull. Cut the engine clean (turn off the ignition) and allow the car to coast to a stop (either on the dyno or on the street). Pull the plug and look very carefully at the base of the insulator (you'll need a good plug inspection tool or a very good eye and lighting). There should be a carbon ring just above the junction of the insulator to the shell. If the mixture is correct (at least at WFO) that ring should be about as think as a dull #10 pencil. If it's thicker and higher up the insulator you're probably too fat. Adjust mixture, put in a new plug and repeat. The top of the insulator should show no carbon. In fact, depending on the kind of gas it's usually almost colorless to a light tan. But don't use the color as a tuning indicator. Once you get the mixture right its time to look for timing. Look at the last plug you inspected for mixture but this time look at the ground strap. The strap should show a slight but definite color shift somewhere along its length. The closer this "change" in color is to the tip the cooler the combustion is and the more timing you can crank in. The general rule is that you should adjust timing until the change occurs about in the middle of the ground strap. More towards the tip the safer. NASCAR guys tend to run on the safer side. Drag boys run more to the base of the strap (towards the threads). Once you got the timing right look at the insulator again. If it looks like it has tiny black spots it's getting too hot and you'll need the next range cooler plug. Now put all new plugs in and do a pull just to check for equal fuel distribution. Pull all the plugs and readjust your fuel and timing to the plug (cylinder) that looks to be running the leanest/hottest. Of course, you'll want to start the process with mixtures and timing on the safe side and if you get any detonation let off immediately (although you shouldn’t at the boost level you’re running unless something else is wrong).

Oh, why the heck would RA-1s work worse than any other tire without lots more camber? Just about every car will benefit from increased lateral force created by camber thrust (within reason, 2-3 degrees) but I don't understand why one would suffer without it just by going to the RA-1s?
 
Thanks for the tutorial on spark plugs! Very interesting stiff, is this better than a wide band O2 for tuning fuel? I am still waiting for more dyno information, just because they had the dyno booked for other cars they didn't get mine back on the dyno today.

There is something about the way the RA-1 is built that they really don't hook up with out some negative camber, at stock settings, (for '91)-1/3 degree, +-1/2 degree you could have no negative camber and still be in spec. I have not heard of any one who really raves about the tires who is running less than -1.2 degrees, I noticed a giant difference when I went to -2 degrees. Now I like the -2 degrees for everything, and with -.1 degree toe out my tires are wearing pretty dead flat.
 
titaniumdave said:
Thanks for the tutorial on spark plugs! Very interesting stiff, is this better than a wide band O2 for tuning fuel? I am still waiting for more dyno information, just because they had the dyno booked for other cars they didn't get mine back on the dyno today.
.

Typicaly I use WBs to get in the ballpark and the plugs to fine tune (as well as a sensitive ear and an electronic listening device) . WBs can be helpfull in sorting out the lower load/rpm points of the fuel map as well but you'll probably end up tweeking these based on fuel mileage and drivability. My experience with my personal WB and those from a few dyno facilities shows none agree, to the tune of +/- 1.5 points or more. My plugs and the dyno have the final say.

Ask your tuner if he/she did a plug check, that'll tell you something.
 
I'm not sure some people will understand what Mark means by "cut the engine clean". Basically with your new plugs in, make a full pull(either on the dyno or on the street). and as soon as you hit your redline, turn the key off imediately(shut the car down). Then follow the process that Mark describes, he's got it down.
 
Well here is the latest up date, dyno pull with open headers drops down to 300 rwhp. So that is not the issue.

Timing was synched correctly.

Intake temps are running pretty high, up to 220F. Not good but not all that uncommon.

Next place to look? Seems like the plug checking is for fine tuning and I am not even in the ball park... :frown:
 
Dynos (and dyno operators) are fickle. Id try another facility before I jumped to conclusions. How does the car feel seat of the pants? You might need to re-calibrate yourself by driving a stocker and then compare.
 
The dyno pulls have been on different days, with different weather with consistant measurements. This same dyno and tuners have seen 360-370 rwhp with this same set up so I tend to think it is an issue with the car. It has always felt down on power from the seat of the pants feel, I guess this is confirming that :frown: I wonder what it was doing before the high boost/AEM mod? Once again, this is why one should do a baseline pull, before doing the mod!
 
titaniumdave said:
Once again, this is why one should do a baseline pull, before doing the mod!

I was debating this but I think its only appropriate to get a baseline dyno test before I install the supercharger next week :wink:
 
If you'd like to see a comparison dyno for a similar setup as yours, do a search on dyno under the name NOTKTS. Ron's car was tuned at Autowave to approximately 380 hp using a similar configuration.

Good luck.

Cheers,
-- Chris
 
Is your Variable Valve Timing working? It can be diabled using the AEM if you're not paying attention. If you have a laptop you can actually test the entire system end-to-end without even breaking an idle.
 
Mark911 said:
Is your Variable Valve Timing working? It can be diabled using the AEM if you're not paying attention. If you have a laptop you can actually test the entire system end-to-end without even breaking an idle.
Already thought of that one, kicks in at 4500 RPM now...very smooth transition but still no power :frown:
 
titaniumdave said:
Already thought of that one, kicks in at 4500 RPM now...very smooth transition but still no power :frown:

Are you going by what the programming says or are you physically seeing/feeling it? I'd change the option setup so that that it kicks in at loads/throttle position/rpm that you'd see at idle and just toggle the activation switch on/off and see if your idle speed changes. Check both circuits. If you get a reaction it's probably functioning correctly at which point you can re-set everything back to the original parameters. Although I can't see it making that much difference, you should check the variable volume valve as well. Have you done a cylinder balance test?
 
titaniumdave said:
Already thought of that one, kicks in at 4500 RPM now...very smooth transition but still no power :frown:

You and I have almost exactly the same setup, except I have fuel pressure logging and EGT logging as well, and out of the box without any timing adjustments from the startup calibrations we pulled 328 HP and now lets just say I have tuned to what I feel is very good numbers. You have checked compression, now do a leak down test.

Are both of the O2's reading very close to each other or is one bank off by more than 1% (look at O2FB if you have feed back active). Intake temps are higher than mine, peeks of around 215 for me and around 175-180 for normal running with some quick starts. Have you double checked the timing, it is a bitch to check and I would not take anyones word for it, the plugs will tell you allot even more than just fine tuning. If you feel comfortable with me looking at you config file email it over to me. PM me and I will give you my email info. If I can help I will try.

Have you logged any of your pulls? log information may have clues to what is going on.

I hope you get her sorted out soon, the 9lb setup/AEM is allot of fun.

Dave
 
I got the car back on Saturday evening from Torque Freaks, even if the numbers on the dyno are disappointing, the drive on the street is pretty damn fun. The power is much fatter in the low mid range, pulls strong up to almost 7000 RPM, then seems to flatten out. All this bodes well for a fun track experince, which is what I am looking for. This is the first time I have been able to light the tires up with the slightest drop of the clutch, before 3-4000 rpm clutch drop meant a quick start from the line, now I can smoke the tires and go nowhere! :wink:

I have a track day on Friday, I will do some data logging and get back to you all. On the track it is pretty clear if the spool valves are working, at PIR it is 80% in Vtec so the oil pressure read on the dash drops about half way around the track, but I will play with that as Mark suggested.

Dave, I will take you up on looking at the config and send you my data logs too. Thanks for every ones help. I will have a chance to do more diagnostics next week, including a leak down test.
 
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