RS back on the dyno......again, ignition and muffler testing.

davidbuschur · Jan 30, 2009, 02:59 PM

I am working on some more changes that I am preparing to make on my RS. In order to do this I wanted to get a baseline on the car again and I had a few things I wanted to try and test.

The last time the car was on the dyno it made 683/551 without any smoothing of the graph, dyno sheet printed was 677 whp if I remember correctly.

I changed a few things. I changed the spark plugs I am running to a very high end NGK racing plug. The plug is a #5442, it's iridium, 8 heat range.

The first few pulls on the car I did with a new muffler in the exhaust. I'm getting old and I am tired of the noise to be honest. My car has the JDM EVO9 rear bumper cover on it. We make an exhaust specifically for that rear cover. The exhaust puts our bullet muffler in the center of the car so there isn't a big ugly can hanging out of the rear. This leaves your options pretty limited to make the car quieter if you have that rear bumper cover.

The new muffler is very small in diameter and is straight through 3", therefore I am going to refer to it as the SD (small diameter) muffler. I didn't expect much in noise reduction from it. I did some decibel testing at idle only and was pleasantly suprised. My car at idle dropped nearly 4 decibels. That is substantial as 3 decibels to the human ear is twice as loud. It took nearly, if not all, of the raspiness out of the exhaust.

Now for the power testing. I made a few pulls with the additional SD muffler and was shocked to see the power, the car made 694 whp and 550 ft lbs ot torque. That is the best power my car has ever made, that was in 3rd gear.

We then took the SD muffler out and put the straight pipe back in. The changes were so insignificant that it's hard to say if there was actually any change or not, 694 whp and 554 ft lbs of torque. The boost did change slightly, less than .5 psi in a few spots, which could account for the slight increases around 6,000 rpm.

Here is the dyno graph of the SD muffler/bullet muffler combo vs. the bullet muffler by itself:

I think for the small changes in power I will be keeping the SD muffler on my car, it is so much quieter and enjoyable with it. Here is a picture of the new SD muffler installed in the rear section of our JDM EVO9 exhaust:

Now that I completed that testing I had another mission. My personal car has a slight studder in it at part throttle cruise that is only noticable on the dyno. I cannot feel it on the street what-so-ever. I have blamed it on just about every part you can imagine on the car and swapped just about everything you can imagine. It is just barely there and annoys me. I have heard about this same thing from other customers too in the past.

One of the things I kept going back to time and time again is the COP ignition. I was quite certain that this feeling was from the ignition.

We have, as I have said before, wired our COP's per M&W's instructions. We have also run M&W's harness that they sent us directly. NONE of these changes have had ANY effect on the cars drivability or performance.

Well today we have a car in our shop for a very large build and in the trunk of the car was..............a complete Spark Tech ignition. I've read here and in other places about our competitor Spark Tech and heard how this and that are different etc. Him and I have spent more than enough time argueing on EVOm about our products.

Given the car was on the dyno for testing and I had the opportunity to very easily put our competitors ignition on my car I went ahead and installed it. Needless to say we also looked it over very good. The unit is wired just as M&W's instructions suggest.

I'd like to say something nice at this point in time but given the fact it will show up in someone's signature or their advertisement I will not

The only problem found is the main connector doesn't have the insert in it to lock the pins in place. I'm sure after this comment, like others I have made though, it will now be corrected.

With the Spark Tech ignition installed on my RS I did some testing and of course a dyno pull. Honestly, no difference. No change in this "jerkiness" I was feeling, no change in power, nothing. If I had not changed the ignition myself I'd have never known anything was different.

So, with that behind me I was still fixated on what this feeling was in the car. For the first time I got the bright idea to pull the COP off the car and simply run a set of stock coils and stock plug wires. I didn't do any WOT pulls, this was only to find out what was causing the car to studder. No change again.................SOB!!!!

I guess this rambling about the ignition wasn't really needed but I know there are other guys who have this studder in their EVO's too. I also know that with a lot of talk I have seen and heard there is some thoughts that it is related to the COP's. This does NOT seem to be the case, whether is it ours or ST's.

I will have to get on a mission to find out what this annoyance is, atleast now I am 100% certain that it is nothing to do with the ignition.

Anyone shopping for a COP can be confident in buying either unit.

Next week will hopefully bring some further testing.

Just for a quick description of the car for those that are going to ask:
BR EVERYTHING

Stage 3, 2 liter, standard bore
Stage 3 head
BF272's
PTE 1200's
BR double pumper
BR BFIC
BR 3" turbo back
BR COP
AEM EMS
BR forward facing turbo kit
HTA86
Wilson V2 intake
BR 65 mm throttle body
Peak boost, 41 psi

RAbishi · Jan 30, 2009, 03:36 PM

I might just have to get that SD muffler when I order my exhaust from you. Quieter and no power loss, it doesn't get much better than that!

Meeh Lucky IX · Jan 30, 2009, 03:39 PM

Nice write up Dav I remember having that studder as well on partcial throttle when I had a VTA Bov it got so annoying I ended up selling it and going back with the Evo9 Bov. Almost at 700whp thats amazing can't wait until your Street RS go's into the 8's : )

Guerillah · Jan 30, 2009, 03:46 PM

Awesome results. How much is that rear section going to cost?

davidbuschur · Jan 30, 2009, 04:15 PM

I don't have the pricing finished for the SD muffler. It's going to depend on how it's ordered. Cheapest way to get it is with a full exhaust system. Building it as a replacement for any part is going to be the most expensive because it has to be built with seperate raw material rather than cutting a section out of a complete exhaust system and put in place of a piece of pipe that is already there. The muffler itself is only about $90 I believe.

Sorry, I should be more prepared for the pricing question.

crcain · Jan 30, 2009, 04:20 PM

Nice post... so how come she got more powerful though? Also I'm forgetting the heat range of NGK's... 7 is standard and 8 is one step colder yes? How come you didn't try a WOT pull with the stock coils?

ExViTermini · Jan 30, 2009, 04:24 PM

The stutter you speak of I've experienced in my own cars, though it was very noticeable on the street

I'm sure you have, but in my efforts to maybe offer some semi-form of help or solution, have you tried pulling out timing in that area or changed the dwell?

This helped my car tremendously, almost to the point of it not being there...

davidbuschur · Jan 30, 2009, 05:30 PM

crcain, the extra power.......I'm guessing most of it is from simply the difference in the air. While the intake air temps were very close to equal from the last testing I did it was colder today than any other time I have dyno'd the car. Yes, the 8 heat range is one step colder. I know for sure the car would misfire on the stock coils/wires, I saw no point in letting the car misfire for no reason. It's hard on everything when it happens.

exvtermini, yes, I have moved the timing and the dwell settings around in the past, it is a very good suggestion though. There are a number of things in the ignition set up in the AEM that I don't agree with 100%. I need to take an extensive amount of time to look into it further and mess with nothing but these settings that do not seem to be right to me. I think some of these settings are the reason people foul plugs and have more misfire problems than on the stock ECU.

**SASD209** · Jan 30, 2009, 05:54 PM

Here we go again. This time I have even less patience. Posts deleted. If the posts re-appear, poster will be banned. If this gets off-topic and out of hand, same thing: a ban. Don't test me people, I stand by my word. Now, let's keep this on-topic and factual. Carry on.

vwjeff · Jan 30, 2009, 07:42 PM

Its BS your car makes that kind of power in 3rd gear

Thanks for the testing buddy, that new muffler looks very nice! I wounder if it is better than my "old" school race muffler?

davidbuschur · Jan 30, 2009, 07:57 PM

I'd say it's better and I'd say it's quieter too! You're going to like how my car sounds.

LoKiEvo · Jan 30, 2009, 08:51 PM

Hey Dave, any chance we can get a picture of how it fits w/ your rear undertray? What about a video comparing the 2 sounds, give us a sample of how much quieter it is.

Also, I know your theory behind the 3rd gear dyno pull, but I think everyone would love to see what the car makes on a 4th gear pull.

DynoFlash · Jan 30, 2009, 10:56 PM

Quote:

Originally Posted by davidbuschur

crcain, the extra power.......I'm guessing most of it is from simply the difference in the air. While the intake air temps were very close to equal from the last testing I did it was colder today than any other time I have dyno'd the car. Yes, the 8 heat range is one step colder. I know for sure the car would misfire on the stock coils/wires, I saw no point in letting the car misfire for no reason. It's hard on everything when it happens.

exvtermini, yes, I have moved the timing and the dwell settings around in the past, it is a very good suggestion though. There are a number of things in the ignition set up in the AEM that I don't agree with 100%. I need to take an extensive amount of time to look into it further and mess with nothing but these settings that do not seem to be right to me. I think some of these settings are the reason people foul plugs and have more misfire problems than on the stock ECU.

I agree on the aem ignition settings

Interestingly with the HYDRA ems I have been running up to 700 whp at 28 psi with the stock coils and wires no HKS twin fire

With an AEM a twin fire is required to make that kind of power

I suspect the issue is in the drivers themselves and not in the software settings

I am anxious to see the new AEM boxes comming out and see if they have improved upon some of these issues

BTW - great testing David - keep doing what you do !

Johnboy1065 · Jan 31, 2009, 02:33 AM

will you be offering this SD muffler in a slip fit???

davidbuschur · Jan 31, 2009, 08:34 AM

I will post pictures of it on the car next week and I can try to video the car with and without it. I have a feeling it is going to be hard to tell from a video but we can give it a try. Please shoot me a reminder in my PM's next week if I seem to have forgotten.

Personally Al, I don't think it's the drivers, I'm pretty sure it's in the software settings. You and I will have to talk about it further off the forums but there are definetely some things in there that can not be right.

johnboy, yes, for sure it is offered in a slip fit. We built a few of those already and shipped them out.