gurgenpb: I was just throwing that out as a possiblility. I really don't know what to think for the real reason. But you are still saying that the 6mt is making more power than the 5at, right? If that is the case, then your initial statement of both of them making 260 at the crank is contradicted. I guess I could see nissan making the 6mt with more HP, because it is considered more of a "sports" vehicle than an AT. Personally, I would have bought a 6mt, but I bought my vehicle to late, and I wanted to take advantage of the 2003 savings. I couldn't find EXACTLY what I was looking for. This is my first AT out of 9 cars that I have owned.

'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Z pipe, Clear Corners, Alum Pedals

 

khsonic,

let me clarify...

The 2 cars are both rated at 260HP. Above, when I referenced that the two actually make the same HP was under the assumption that they in fact are making 260 each. Rememeber, we are all just trying to make sense of what is going on through inductive reasoning - this is just one of the possibilities.

However, as DaveO has discussed with me on the phone, it is a very good possibility that in fact they do not make the same 260HP at the crank (as outlined in my previous thread) and that the 6MT is just underrated comapred to the 5AT. THis is another possibility. THe truth is, that none of us does not know for sure. I am here just to presentthe best, most logical conclusion given the facts.

Arguments can be made both ways... I am leaning toward the 6MT being a little (~10HP) underrated compared to the 5AT. But as we all saw, this is easily made up by the ECU upgrade.

Gurgen

2003.0 G35S 5AT Aero/Sport
<font color=blue>TS ECU tuned for mods</font color=blue>
Injen CAI
Crawford Plenum
Crawford High-Flow Cats
Fujitsubo Y-pipe/22" Magnaflow Resonator
Eibach Pro Kit

 

I would agree with that. From what I have seen and read, it seems to be a logical assessment. Underrating is not unusual, as many times manufacturers want to keep their flagship sports car, and not have a car considered less sporty making the same HP. This is a good case for the mt sedan vs the coupe. Other times underrating is done for insurance purposes, like the 03 cobra (rated at 390, but really produces about 420HP). Maybe I just don't want to admit it because I love my AT and I'm a little jealous. LOL. I am definitely looking at the TS as a future upgrade for my vehicle. It would seem to me that the difference in cams could definitely make a difference in HP, as well as the cooling fans and the ECU. If TS can't get much more HP out of the mt sedan, then the ECU is most likely the main culprit.

'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Z pipe, Clear Corners, Alum Pedals

 

gurgenpb, I understand about the EPROM flash and how it works - that's the point. Technosquare could license to other shops like many companies do. Guy named Jim Conforti came up with an EPROM flasher for BMW called the Shark Injector, it sells to owners and shops like crazy at $399. Technosquare will never get the business they are capable of (about 50,000 cars and counting) with people having to pull and ship in the ECU. They're not getting mine! Just my two cents, nuf said.

Clutch fan doesn't run all the time so loss is limited, check the hp the electrics draw when on and compare -no big deal either way. I do like the electrics better for heavy traffic and engine load.

6MT sedan has different cams and less drive line loss so it does in all probability make more hp at the rear wheels, even if it makes the same at the crank-is it comparable to MT coupe? Probably. Same holds for comparison of AT sedan and coupe.

Surprising thing is watching everyone here and at FA and My350Z going thru major mods at big expense when fastest, cheapest mod for better acceleration is simply a higher set of gears. Torque multiplication is directly proportional to gear ratio. Changing to 3.73 or higher (don't know Nissan ratios anymore) will dramatically improve acceleration at some loss of mpg.Manifold changes, intakes, cams etc, generally drop low end torque and may in some cases actually drop acceleration even though HP increases! Had a friend found this out the hard way with radical cam and ported heads. Gears need to come first. You can easily knock .3 secs or more out of 1/4 mile time if you can live with the gears.
Wheew, talk about long winded! I'm signing off.

<P ID="edit"><FONT class="small"><EM>Edited by jcv on 09/28/03 11:06 AM.</EM></FONT></P>

 

khsonic, ...


we are in agreement.

However, we can definitely do something about the fans. PLanning on gettting the coupe's fan bracket/shroud, and just the passenger side fan, and connecting it up somehow. I can always do it by connecting it to a standalone thermal probe/relay, or try to do it the same way as the coupe (although that maynot be possible if it is controlled by the ECU).

Definitely doable.

Gurgen

2003.0 G35S 5AT Aero/Sport
<font color=blue>TS ECU tuned for mods</font color=blue>
Injen CAI
Crawford Plenum
Crawford High-Flow Cats
Fujitsubo Y-pipe/22" Magnaflow Resonator
Eibach Pro Kit

 

hey jcv

are you saying that the gears can actaully be changed on the car? can you tell us more about that. i assume you mean the first gear only. that;s the one i would love to have some more "umph" on.

agree with you on the cams. It has been raised by DaveO that the autos may actually have cams that make more torque at the expense of slightly lower top end hp, as they already have more gears and can compensate. I would definitely lose low end torque (the thing i need the most now) by putting in cams.

gurgen

2003.0 G35S 5AT Aero/Sport
<font color=blue>TS ECU tuned for mods</font color=blue>
Injen CAI
Crawford Plenum
Crawford High-Flow Cats
Fujitsubo Y-pipe/22" Magnaflow Resonator
Eibach Pro Kit<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 09/28/03 11:18 AM.</EM></FONT></P>

 

try the Nissan tuner shops around you or sgp performance in Houston http://store.yahoo.com/sgpracing-store/index.html
Without LSD, guessing probably about $500 to $600 plus install. Get Technosquare to adjust the ECU to correct the speedo - it can be done.

I'm not saying the gears in the trans but the rear end gears. The AT are only 3.38 cruising gears and could live with about a 3.73 or 3.91 on the street- that will make your car accelerate more than anything you've done to it aready (you will light your tires). It will really help then if you've added to the top end and killed some low end torque (which may be true from your dyno). With gears, I'd bet your AT is a mid to high 13 second car and will be a torque monster. Then get one of these:
http://store.yahoo.com/sgpracing-store/sgpraautrup.html

The AT cams are probably designed for more mid range torque (less duration, lift?) to fit with the converter stall speed, I haven't found the specs yet but still trying. The HP on AT and MT maybe the same, just the torque profile differs. The higher gear ratio of the MT cars overcomes low end loss.

If you do 1/4 mile or street drags, the usual route is gears, intake/exhaust, headers, high stall converter, cams. Anything other than the gears kills low end and adds to upper end hp/torque so thats why you start with gears. It helps with road racing too but typically not as much since your rpms are usually near max most of the time. Been this route many, many years ago with a D/SA Street Hemi stock class drag car (no ECU just my tuning) and others (the wife's car was a 440 RT with auto) with a high stall converter and gears, that car would light cheater drag slicks almost the length of the strip- yahooo.

<P ID="edit"><FONT class="small"><EM>Edited by jcv on 09/28/03 03:45 PM.</EM></FONT></P>

 

jvc,

Help me out!

You stated the following in a post above:

"Coupe and sedan (and 350Z for that matter) are both single exhaust, coupe has a different resonator and sedan has a variable muffler-really minor differences. Intakes are the same. I agree the AT accounts for some difference in acceleration and HP, and the cams in AT cars and MT are not the same-I've checked."

I agree with most of your statement, however my sources indicate the same camshafts are used for all MT and AT cars. It was explained to me that there's four camshaft part numbers, one for each intake and one for each exhaust bank.

Please confirm or provide your source and/or part numbers so we all can update our knowledge.

DaveO

 

Local Houston dealer parts manager who looked it up for me-North Houston Infiniti. Got same answer but no p/n confirmation from West Houston. I was trying to get a look at the parts book myself but haven't had a chance yet.

I tend to think this is so since it would be very, very unusual for any car to have same cams for AT and MT. Normally, the AT is tuned for mid-range to work with converter and less gears. MTs usually have one more gear to work with and higher ratios. Now, the other possiblity is the cams are the same and the ECU is used to control the valve timing differently for the AT and MT but I doubt this.

The other thing I'm trying to check is whether AT/MT cams for 350Z are the same as G cars. I 'm guessing they are but will check and report maybe next week. I think there are only tow engine versions-AT and MT for all these cars.

I've really been trying to look at ring and pinion sets and what will fit. In technical terms, screw the other mods-get gears and fly. More top end with no gears is not much faster I've been there, done that when I was young and dumber as did some friends. And God help you if you put in cams and exhaust with no gears- can you say no low end acceleration!

<P ID="edit"><FONT class="small"><EM>Edited by jcv on 10/02/03 07:54 PM.</EM></FONT></P>

 

DaveO, I stand humbly corrected after further digging. Right you are about the cams, they are the same for AT/MT sedan and coupe! With more digging, the same is true for 350Z, AT/MT are identical. What's more it looks like 350Z cams are the same as G35. Talk aobut common parts across platforms!
for reference here's two 350Z p/ns.
350Z left intake p/n 130208J106
350Z right intake p/n 130208J101

Seems like primary difference is ECU, minor intake difference and minor exhaust difference (they're all technically single exhaust).

What a fine kettle of fish this is. It means you can buy cheaper parts from Nissan,

 

thanks a lot jcv for clearing that up. That's what I was hoping for. Our cars DO have identical engines, and can make identical HP/Torque at the crank

Gurgen

 

Damm good info guy's, I'm putting my UR underdrive pulley on this weekend and next month I will be getting the ECU tuned. I have been debating on this ECU upgrade but now I convinced I'M DOING IT, thanks for the great debate !!!

 

Gurgen.....You think If i get the ECU Re-program for my 04 6mt Coupe it would be a night and day difference?
My last Dyno without the headers and plunum was 391HP @ The rear axels

Current Mods
---------------------------------
Vortech Intercooled centrifical supercharger
Crawford V-5 Plenum
Crawford High flow cats
Pro-1 Y-pipe
DC Headers
RS*R Concept cat back system
Nismo lightened flywheel
ACT 8-puck clutch
NOS Intercooler spray bar kit
-----------------------------------

I should notice a pretty good difereance ya?