"This kind of stuff drives me nuts. I really try not to spread MISINFORMATION, but please don't use countless hours of my own hard work to try to "fabricate" hp claims. The goal of the Central Florida Dyno Day write-up was to let people see different G35's in various states of tune (reads with different mods) so you can see how these mods work together. Let's use the data for that purpose and that purpose only, please...

...and incase you're wondering, Yes I took your post personal, because I put a lot of effort into obtaining all of the data and posting it to help people like yourself and it appears that you're trying to use the data to make stuff up. The whole point of posting the data was to keep people from having to make stuff up, get it?"

Use stuff against you eh? I actually think what you guys did was tremendous - hell it got me to put the z tube on in place of the Injen. If you take it so personally you will be hopelessly offended..I look at the same data and draw conculsions and throw the m up there for trouncing just like everyone else. How is that using anything against you. Your argument is that the plenum causes HP loss which I will vehemently suggest is either an anomoly or an ECU issue very likely related to the mapping for the 6sp. The 6 speed have more power is consensus so why wouldn't the subsequent mods be less effective? Once you start approaching the HP limit for the VQ there is a diminishing return. I dont buy that the plenum affects the auto in the same way as the 6sp based on conversation had with the crawford folks.

16 hp is a bunch and and its right on the sheet like it or not. I bet the auto gets 20 based on comparing runs at the atco event. The proof is in the pudding. That crank pulley cant be the reason I got .8 seconds better than stock can it?

Enjoy the debate for what it is and dont take my 2 cents so seriously. Data can be interpreted in many ways and life is too short.



2003.5 DP 5AT Sedan (E-thing but Nav)
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Polk EX-3500 Tweeters/Shock Sensor/H-Liner

 

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

Your argument is that the plenum causes HP loss which I will vehemently suggest is either an anomoly or an ECU issue very likely related to the mapping for the 6sp.

<hr></blockquote>

Go back and re-read my posts. I'm saying the plenum produces a GAIN and I cannot understand how people are reporting a loss! I'm also saying that you should not use the data from the dyno day to "extrapolate" hp #'s like you did in this next direct quote…

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

In the first chart with the matrix of drivers - Take Driver #1 with the plenum, the Cats and Z tube and pop charger and compare to Driver # 4 who is stock. 16.7 diff at rear wheel right off of the chart. Now assuming Driver #1 had stock cats and NO pop charger the Hp # might go up by 4 or so and be exactly 20 higher than the stock #4 car.

<hr></blockquote>

This is what I’m talking about when I say people are extrapolating bogus data. What part about the stock catalytic converter don’t you understand? It is NOT helping to produce gains; it’s just the opposite. It’s helping to REDUCE emissions by restricting performance to a degree. Why do you think people would replace the stock cats and pay good money to free up airflow? They do this for a performance increase. The same goes with modifying the stock plenum. Is it possible that the plenum loses hp w/o some proper intake, exhaust modification? POSSIBLY. Since I modified the cats before the plenum I did not see any performance loss what so ever. To those who are modifying the plenum first and seeing a loss I can only make 2 recommendations.

1. Get an aftermarket Y-Pipe, Exhaust or cats QUICK!
2. Sell your plenum to someone on Doug's long waiting list for EXACTLY what you paid for it.

Doug at Crawford shows a dyno where the plenum alone on a stock car gains 11rwhp PEAK. I believe this is 100% true. I also believe that your quoted statement above, directly conflicts with what Doug states. Therefore I disagree with your statement.

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

(my sources tell me the pop charger and/or the cats are bad for HP tho)

<hr></blockquote>

Care to share your “sources” with the rest of us?

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

Use stuff against you eh? I actually think what you guys did was tremendous - hell it got me to put the z tube on in place of the Injen.

<hr></blockquote>

GREAT!!! THANKS!!! This is what I was hoping for. You are using the data as a factual point of reference and making educated decisions without adding fictitious numbers (or potentially non factual “sources”) to drive your mod purchases. This is why I wished more people would organize dyno days in their areas so that we would know what would happen if someone had HIGH FLOW CATS without a PLENUM. Then someone else would have the PLENUM without the HIGH FLOW CATS. Combine that with a stock car and someone who had both of these mods and this conversation would be over.

301-bhp!!! ...and growing!

 

"Why do you think people would replace the stock cats and pay good money to free up airflow? They do this for a performance increase"

Many buy the Injen for a performance increase that does not mean they get it....lots of mods promise power that does not mean it's there in fact quite the opposite in many cases especially exhaust mods.

Whether you believe sources is not the point is it. I shall extrapolate at will in context of speculating and it should not offend a soul.

As for my sources I keep them to myself but it has been thoerized (just like theres a theory that the plenum is bogus) that the stock cats provide needed backpressure and that the variable mufffler is no longer working properly once the cats are gone. If you say they are better I believe you dude - but is the pop charger killing a couple hp? Who knows without more testing...until then I would hope your publicly published data wouldn't be restricted for discussion by the publisher for only his or her arguments. If you don't like the hypothosis then prove it wrong or allow someone else to. Many have speclated that my mods dont do squat and I just prove they do and try not to feel hurt.

2003.5 DP 5AT Sedan (E-thing but Nav)
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Polk EX-3500 Tweeters/Shock Sensor/H-Liner
<P ID="edit"><FONT class="small"><EM>Edited by SixFive on 06/02/04 07:32 AM.</EM></FONT></P>

 

I believe 65's "source" is probably a botch at attempting to regurgitate the statement by Eagle1 that he experienced a HP loss when he put his headers and exhaust on. Here's the quote from Eagle1's article:

"Interestingly, changing the catback and the headers resulted in a dyno pull of 10hp less than without those mods. Putting on the high flow cats then resulted in an 18hp gain, to 346+, and 306 lbsft torque with a conservative tune."





2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5

 

No...but feel free to speculate at will! It's more like a mosaic of information that is pieced together to come up with an idea that is either rethought or verified until it's rethought again and possibly verified or not. NONE of my opinions are set in stone and they are only SixFives opinions anyway! I don't mind that people get emotional about their mods I just am not sure why they do to such a degree that speculation would offend them. Its just theory until proven otherwise....and I am in the market for cats if they are really good for power but based on what I've seen and heard about intake and exhaust for this car - the stock package is hard to beat. I would love to mod the exhaust but prob won't unless headers and a catback are good for a proven 20...and then it is still a sedan so maybe not if the sound is too much like a procharger which sounds like a ferrari.

2003.5 DP 5AT Sedan (E-thing but Nav)
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Polk EX-3500 Tweeters/Shock Sensor/H-Liner

 

Quote:
"They are backed by the manufacturers, ricer math does not prevail, normal engine tolerances should not swing by 5% (come on people, haven't you heard of precision machining?), etc... "
____________________________
According to Q45tech, there can be up to a 2 hp variance + or - per cylinder. (I don't take everything Q45tech has to say as gospel, but you have to admit, he knows a lot. Besides, 2 hp per cylinder seems very reasonable.) Based on that, a coupe rated at 280 hp could in have anywhere from 268 to 292 straight from the factory.

The point of my last post in this thread was that there are too many variables and that dyno figures should be taken with that in mind. Perhaps you got an engine at the lower end of the tolerance and your mods made a huge difference. In the alternative, you may have gotten a particularly strong engine and your mods may not have done much. That's all I'm saying.

BTW, do you know how much of the engine is precision machined? I don't but I'm sure the majority is cast. Even Ferrari casts a majority of the block.

 

Q45tech also said this:
"Sometimes in warm weather the injested air is warmer [using pop charger] than what the oem provides......serious idle and slow traffic problems all depends......each 11F hotter is a 1% minimum power decline.....there is also a summer safety program to reduce ignition advance when the outside temp exceeds 90F, just like the similar program when coolant goes above 194F.

All in all not worth the hassle unless you just demand the sound and don't care about driveability in Summer."

This really bothers me, the ambient air in Florida will be hotter than 90F until October. I have reduced power all summer??
Even sticking with the OEM setup won't help in that case.

It was hotter than 90F on dyno day.

al503, I agree with you that there are too many variables to compare dynos, this is why we tried to reduce as many variables as possible by doing 18 different cars with different setups on the same day, with the same dyno, with the same driver, in the same gear.

We tried anyway.



2004 G35C 6MT Black. Ok. It's only May. Black cars are hot. In more ways than one.....

 

hey DED,
I agree that you guys did the best possible job by doing all of the cars on the same day on the same dyno. No disagreement there.