I thought I would start a new thread since my previous “Testarossa” post threw a few folks off . Here are the pre and post dyno results where the only mod change was the Crawford plenum. The plenum was in the vehicle for 375 miles (8 days) before the post plenum dyno run and the ECU was reset at install. I only have AF results post plenum but I’ll speak to that on the AF post below.

The pre plenum runs are 001-003. The post plenum runs are 004-007. I threw the high and the low out of each set and took the middle of each to compare which are runs 002 and 006 and are shown in the pic. All seven runs max power and torque were:

With z tube, K&N filter, 10 Wire Grounding Gear
Run RWHP Torque
001 224.1 224.5
002 225.7 225.8
003 228.1 223.1

With Crawford Plenum and the above
Run RWHP Torque
004 233.9 238.2
005 232.0 229.6
006 231.2 231.1
007 229.7 226.3

In the pic above the top circle is on the torque curve and here is what I spent $437 on: without the plenum torque comes in at 3200 rpm but with plenum MORE torque comes in at 2600 rpm, a VERY good thing, more low end torque. Same story for HP although not as pronounced, more power at lower rpm (bottom circle). As you can see up the rpm band HP and Torque track about the same for both runs until red line where the plenum delivers its peak 5.5 HP additional gain. This goes right along with what I could feel, I knew the day I installed the plenum the car had more low end kick. See next post for the REST OF THE STORY….Rod


03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5



291732-Dynobef_aft_plen.jpg

 

Now for the AF and I need some help here. The pic clearly shows the car leans out between 3300 and 4500 rpm (the circle) and then goes way rich beyond 5000rpm (the arrow). I unfortunately don’t have a pre plenum AF chart (long story I was DUMB), but if you compare my AF with a post by SCOBIC on a stock 2003 6MT (I am AT though). My AF looks BETTER than his in the 3300 -4500 band. But he stays above 13:1 from 5000 and beyond and I go to rich land. So, what next? My dyno guy doesn’t think I’m so lean (especially on the street vs. the dyno) to mess the car up and I can with no engine concerns do:

A) Nothing, find another hobby to sink money into
B) Forget any other air mods and do the TS ECU reflash
C) Change the cats to hi flow and then do the TS ECU reflash
D) Change the cats and the exhaust and then do the TS ECU reflash
E) Any of the above except A and do the APEX II AF controller instead of TS reflash.

Opinions would be great. Hope the above is useful to folks….Rod


03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5



291743-G35 plenum and side shots 007.jpg

 

Nice data.

At least several of us have done cats/plenum in different orders and have found a much more pronounced gain after doing both plenum and cats.

Personally, I'm taking the C or D route, whichever is available first.

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats/ Service Engine Soon

 

The high torque you initially have appears to be due to the torque convertor. The torque values there are higher than the torque at 4500K (where max torque should be). I can't explain why you didn't have that surge with the nonplenum runs.

The last time I dynoed, I had 240 ft lbs of torque at 2.5K, and this was clearly due to the torque convertor. A 350Z had 275 torque at that rpm on a dyno graph I saw on my350z.com. Everyone attributed it to the torque convertor's torque multiplication.

Thanks for posting the before and after dynos.

 

Rod,
Thanks for sharing the data. I'll have to agree with E_K. The spikes at the low end should be disregarded due to the nature of the torque converter.

I must say I was really hoping to see some solid gains with the addition of the Crawford plenum. It looks like you're actually losing power between 4000 and 5500. You did appeared to be running on the rich side. Again, it's a shame you do not have the pre-plenum AF data for comparison. None the less, you did gain around 6hp at the top end Things are likely to improve if you can straighten out your AF. TS ecu could be in your future.

Clint (THX723)

 

I think you should offer to buy Gurgen's old RT Cats, throw them on and then re-dyno. -Fish just did this and he saw/felt some pretty good gains, just as I did.

Also, the initial spike in hp is due to the torque converter slipping. This only happens on the 5AT's. This is what set off your dash lights after your run was over. I bet the lights freaked you out for a second (the first time you saw them) but went off right away and stayed off. [img]/w3timages/icons/smile.gif[/img] Does this have a ring of truth to it?

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

If the A/F spikes are truly spikes, then this looks like a very conservative A/F ratio and probably not much difference from stock. Anybody know how much the addition of high flow cats would change this?

'04 6MT coupe

 

The WOT AF ratio is pretty much preprogrammed per rpm and tps load..[the VE chart].......then fine trimmed for temperature and barometric changes by the MAF.
The ecu knows that a range of zero to 160F air temp[from 60F][+5-10%] is possible as is sealevel to say 10,000 feet [-30%[ it gets colder the higher the altitude] so -30 below at 10,000 feet is possible - works out to -25% worst case situation. 20% leaner than 60F at sealevel

But ODB2 allows only a 20% variance from standard factory conditions before it throw a MIL code.

Very unlikely that any external mods [all combinations] can affect air flow by 5-10%.

Reading AF on a Dynojet has serious errors because the engine accelerates too fast on the dyno [not real world highway acceleration]. Also measuring AF after the cats is prone to error.........must be measured prior to 1st precat!


Gaining 5% more RWHP doesn't mean that you have gained 5% more air flow it can mean that something caused the AF to go leaner from the EXTREMELY overrich oem protective setting thus increasing power with less safety reserve......or that something caused the ignition to advance a degree or 2 resulting in more power with less safety from knock preignition, etc.

Coolant and fuel temperatures are monitored to trim ignition advance as part of Summer overheat protection, the AC signals ecu to confirm hot day and reduce power to prevent knock under sudden acceleration.

Lots of checks and balances.

Leaning the engines with mods is good as long as the intake heat doesn't make the air charge hotter and less dense.

ECU/engine is self protected from most owner cause destruction other than not changing oil every 90 days assuming the coolant doesn't over heat!

 

E_K, the dyno guy did the driving both sessions and he felt the torque converter lock up at 3200 rpm (see the spike on both runs) I think that was the surge...Rod

03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5

 

Rod,

the TC does NOT lock up at all according to our shop manual and my own tests until 4th and 5th gear (and even then during cruise only). You can try this for yourself, as you shift into a particular gear, set cruise control right away and watch for an rpm drop. This only happens in 4th and 5th gear (just like written in the FSM).

Gurgen

 

Cat,
thx for the reply.

THX723,
The dyno guy thinks the torque spike at 3200 was the torque converter locking up ( he said it felt like an extra gear) so I don't know if you throw out the low end stuff or not. I defintiely have a rich issue at >5000rpm and leaning that out would make more power but I again say that my AF looks better than a stock 6mt post by SCOBIC between 3500 and 4500 (where you will run more than above 5000). So I don't know if I'm really that lean overall.

Neff,
If you mean SLIP, ABS, and VDC Off lights were on after the run your right and I only freaked when I hit the VDC off button and nothing would happen. The dyno guy said they will go off but I was jittery as I backed out of the dyno but they went off as soon as I put it in D and gave it a little gas. Any idea why that didn't happen on my first session pre plenum?

jjellykneck,
As I said above the only stock AF reference I have I look fine except above 5k rpm where they stay at 13:1 and I go rich in a hurry.

q45tech,
The o2 sensor on the drivers side before the cat is where the AF signal wire went not after the cat but see if I get you with these statements:

1) AF dynos are too error prone to worry with because they don't simulate a street condition.
2) Bolt on mods can't change airflow more than 5% and if you can't do that don't worry about AF mix.

Can you give me a yes or no on those 2 statements if that is what you are saying?

By the way we appear to live in the same city, my email address is on my profile, lets talk.


Thanks for the replies guys....Rod




03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5

 

Rod,

Your a/f is very, very rich, especially on the top end. You are very likely to see some real gains when you correct your a/f. From my observations and from what I've heard and seen about/on different cars, your a/f is ideal in the circled region (low end), but it should gradually decrease to around 13-13.2:1 at redline; this is assuming of course that the a/f readings that you got are reliable.

If you do plan on getting the TS reflash, which i would say you desperately need, you should get it after you get highflow cats or test pipes (if you plan on getting these at all), which will lean out your mixture quite a bit. On my car the mixture went from 12.5 to 13.1 on crawford cats (and RT's I've heard can effect a larger change, but they reportedly flow better).

Gurgen

<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 07/04/04 12:38 PM.</EM></FONT></P>

 

Gurgen,
Thanks for the scoop I too believe I have a rich problem not a lean problem. Can the TS guys program for that? I worry about mail order tuning no dis to any one. Can they program to just my issues with my mods?...Rod

03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5

 

<blockquote><font class="small">In reply to:</font><hr>

The dyno guy thinks the torque spike at 3200 was the torque converter locking up ( he said it felt like an extra gear) so I don't know if you throw out the low end stuff or not.

<hr></blockquote>
Rod,
I would definitely disregard the number below 3500rpm. I'm surprised the dyno tech even attempted full throttle below that point for an AT. You can also clearly see in your pre-plenum plot (in red) that funny stuff is going on between 2700 and 3200. Again, this is expected from an AT car.

<blockquote><font class="small">In reply to:</font><hr>

I defintiely have a rich issue at >5000rpm and leaning that out would make more power but I again say that my AF looks better than a stock 6mt post by SCOBIC between 3500 and 4500 (where you will run more than above 5000). So I don't know if I'm really that lean overall.

<hr></blockquote>
Is the AF measure from the tail-pipe? If so, they give you an ideal of what your AF looks like. You are however definitely on the rich side up top.

Btw ... were you able to get the dyno files on a disk?

Clint (THX723)

 

Clint, I have all the files on disk and the dyno guy went to the o2 sensor on the drivers side just before the cat to take the AF readings but I'm hearing folk say that's a bad idea so I'm a little confused here...Rod

03 5AT-Premium-Aero-Tire & Wheel Pkg-Splash-Z tube-K&N Filter-32% Tint-10 wire Grounding Gear-Crawford Plenum Ver 5