Post Maf Tubes & Drop-ins, worth it??

m4a1mustang · 10-20-2011, 08:47 PM

I knew it was Phunk. He's not going to release it until it's 100% ready. Can't rush that!

DarkZide · 10-20-2011, 08:47 PM

with 9/10s? I dont think there is enough empty space in the tank at that point to ever slosh is far enough to one side. Unless the fuel pump is mounted on the the edge of the fuel tank.

FL 4Motion · 10-20-2011, 08:52 PM

Quote:

Originally Posted by m4a1mustang

I knew it was Phunk. He's not going to release it until it's 100% ready. Can't rush that!

oh yeah, I don't want him to push a half a$$ product ot market either, esp since w/in the next 12-18 months, I'll be getting it.

Quote:

Originally Posted by DarkZide

with 9/10s? I dont think there is enough empty space in the tank at that point to ever slosh is far enough to one side. Unless the fuel pump is mounted on the the edge of the fuel tank.

Ask Mike (the powdercoater), chris slicks, cossie or anyone else here that tracks aggressively.

Even my wife has had to keep the tank topped up betwn sessions and she is not as fast as the guys above...yet. (still getting comfortable with the Z vs our last cars that she tracked that were awd).

DarkZide · 10-20-2011, 08:54 PM

what exactly is the defect? The gas would have to be unpumpable by the pump in some sort of fashion, meaning its sloshing to far to one side or there is a divider thats its getting held behind, etc.

Red__Zed · 10-20-2011, 08:57 PM

Quote:

Originally Posted by m4a1mustang

Sometimes you don't want to run a heavy fuel load, though. Especially if you are just doing a ~60 second competitive autocross run.

Though given the circumstances you kind of have to, but we are getting close to a fuel starve solution from what I have read. Currently in testing but so far it has had positive results.

yep, especially at ~6lbs/gallon for gas. Keeping the Z full is lot of extra weight.
I hope phunk's solution turns out well. I'm surprised it took this long, since I don't think it should be a difficult fix.

Quote:

Originally Posted by FL 4Motion

oh yeah, I don't want him to push a half a$$ product ot market either, esp since w/in the next 12-18 months, I'll be getting it.

Ask Mike (the powdercoater), chris slicks, cossie or anyone else here that tracks aggressively.

Even my wife has had to keep the tank topped up betwn sessions and she is not as fast as the guys above...yet. (still getting comfortable with the Z vs our last cars that she tracked that were awd).

yep. very easy to get stutter-starve with a nearly full tank.

you can actually hear my car stutter-starve on some of our dragon runs, and god knows I wasn't driving hard.

m4a1mustang · 10-20-2011, 08:58 PM

I think it's the fuel pickup placement and the tank design. Take a look at this diagram: 172 Fuel Tank :: Fuel & Engine Control :: Genuine Nissan Parts :: 370Z Parts (Z34) 2009-2011 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

From reading the fuel starve thread it just seems like the pickup is at the front right of the tank, and given the tank design fuel can run away from the pickup even when it's darn near 9/10ths full if you are in the "right" type of right hand corner. Seems like you need to be on R Comps to successfully starve the pump at 9/10ths, though.

DarkZide · 10-20-2011, 08:59 PM

I've never heard it in all my times on the dragon. There are a couple local 370s that autocross quite competitively and don't have it. *shrug*

FL 4Motion · 10-20-2011, 08:59 PM

It has to do with the shape of tank, location of the pickup point iirc. Basically, under very hard right handers you'll get fuel cut, usually it is just a hicup and then you're on your way, but depending on the lenght of the turn, level of gas in the tank etc, it can kill your car, pretty serious issue if you're on the track with other cars imo.

there's plenty of threads on this that will explain it better than I'm doing it lol.

m4a1mustang · 10-20-2011, 09:02 PM

Quote:

Originally Posted by DarkZide

I've never heard it in all my times on the dragon. There are a couple local 370s that autocross quite competitively and don't have it. *shrug*

I never had it in mine either and I have driven the car pretty hard on low fuel. It seems like you really need to be in a long (and hard) enough right hander to keep the fuel away from the pickup long enough to starve it. Probably not going to happen for most people on the street, but definitely presents a big issue on certain tracks.

DarkZide · 10-20-2011, 09:03 PM

I can see it now that I see the shape of the tank, it looks prone to pooling in the lower parts or not being able to flow back over the middle part if its to one side. Would still seem hard to do with 9/10s but i could see it at about 60% or less

m4a1mustang · 10-20-2011, 09:05 PM

Quote:

Originally Posted by FL 4Motion

It has to do with the shape of tank, location of the pickup point iirc. Basically, under very hard right handers you'll get fuel cut, usually it is just a hicup and then you're on your way, but depending on the lenght of the turn, level of gas in the tank etc, it can kill your car, pretty serious issue if you're on the track with other cars imo.

there's plenty of threads on this that will explain it better than I'm doing it lol.

Yep. You really have to be in the corner long enough to kill the car, usually it's just a hiccup that you can recover from. You can draw the fuel away from the pickup but there will still be some queued to get pumped through. If you run out of that and are still in the corner then there's your engine cutoff. I think there needs to be an element of forward acceleration as well since the pump is at the front of the tank.

m4a1mustang · 10-20-2011, 09:06 PM

Quote:

Originally Posted by DarkZide

I can see it now that I see the shape of the tank, it looks prone to pooling in the lower parts or not being able to flow back over the middle part if its to one side. Would still seem hard to do with 9/10s but i could see it at about 60% or less

Yeah definitely easy with 60% or less. I think for 9/10ths you really need to be on R Comps and on track. There's just no other way that I could see that happening with that much fuel in the tank... you'd need a damn long and fast corner to pull it off!

FL 4Motion · 10-20-2011, 09:07 PM

Quote:

Originally Posted by m4a1mustang

Yep. You really have to be in the corner long enough to kill the car, usually it's just a hiccup that you can recover from. You can draw the fuel away from the pickup but there will still be some queued to get pumped through. If you run out of that and are still in the corner then there's your engine cutoff. I think there needs to be an element of forward acceleration as well since the pump is at the front of the tank.

exactly.

Soooo, I'm thinking about getting some PMTs to go with my k&n drop ins, you think it's worth it or should I just get some G3's?????

Red__Zed · 10-20-2011, 09:07 PM

Quote:

Originally Posted by m4a1mustang

Yep. You really have to be in the corner long enough to kill the car, usually it's just a hiccup that you can recover from. You can draw the fuel away from the pickup but there will still be some queued to get pumped through. If you run out of that and are still in the corner then there's your engine cutoff. I think there needs to be an element of forward acceleration as well since the pump is at the front of the tank.

yeah, it's usually happening in turns you are accelerating out of.

a lot of times you won't notice a mild starve. the car will miss, but keep on going...it feels a lot like vdc kicking in

m4a1mustang · 10-20-2011, 09:12 PM

That probably explains why I never experienced it on the street. There are never any real long right handers that you accelerate hard from apex-out on the street. The typical ramp is taken at a constant speed and I am not exactly attempting to pull 1.3G on public roads. I know I have made several spirited on/off ramp runs with the Z on 1/4 tank or less and never had an issue.

Regardless, it's good to know Phunk is making progress and that a solution will be available to those that have the problem (hopefully) shortly.

10-20-2011, 08:47 PM	#136 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	I knew it was Phunk. He's not going to release it until it's 100% ready. Can't rush that! __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

10-20-2011, 08:58 PM	#141 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	I think it's the fuel pickup placement and the tank design. Take a look at this diagram: 172 Fuel Tank :: Fuel & Engine Control :: Genuine Nissan Parts :: 370Z Parts (Z34) 2009-2011 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com From reading the fuel starve thread it just seems like the pickup is at the front right of the tank, and given the tank design fuel can run away from the pickup even when it's darn near 9/10ths full if you are in the "right" type of right hand corner. Seems like you need to be on R Comps to successfully starve the pump at 9/10ths, though. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

10-20-2011, 09:12 PM	#150 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	That probably explains why I never experienced it on the street. There are never any real long right handers that you accelerate hard from apex-out on the street. The typical ramp is taken at a constant speed and I am not exactly attempting to pull 1.3G on public roads. I know I have made several spirited on/off ramp runs with the Z on 1/4 tank or less and never had an issue. Regardless, it's good to know Phunk is making progress and that a solution will be available to those that have the problem (hopefully) shortly. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

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10-20-2011, 08:47 PM	#137 (permalink)
DarkZide Enthusiast Member Join Date: May 2010 Location: TN Posts: 291 Drives: 2010 370z BC M6 Rep Power: 15	with 9/10s? I dont think there is enough empty space in the tank at that point to ever slosh is far enough to one side. Unless the fuel pump is mounted on the the edge of the fuel tank.

10-20-2011, 08:54 PM	#139 (permalink)
DarkZide Enthusiast Member Join Date: May 2010 Location: TN Posts: 291 Drives: 2010 370z BC M6 Rep Power: 15	what exactly is the defect? The gas would have to be unpumpable by the pump in some sort of fashion, meaning its sloshing to far to one side or there is a divider thats its getting held behind, etc.

10-20-2011, 08:59 PM	#142 (permalink)
DarkZide Enthusiast Member Join Date: May 2010 Location: TN Posts: 291 Drives: 2010 370z BC M6 Rep Power: 15	I've never heard it in all my times on the dragon. There are a couple local 370s that autocross quite competitively and don't have it. shrug

10-20-2011, 08:59 PM	#143 (permalink)
FL 4Motion A True Z Fanatic Join Date: Feb 2009 Location: FL Posts: 4,776 Drives: Baby Shark Rep Power: 701615	It has to do with the shape of tank, location of the pickup point iirc. Basically, under very hard right handers you'll get fuel cut, usually it is just a hicup and then you're on your way, but depending on the lenght of the turn, level of gas in the tank etc, it can kill your car, pretty serious issue if you're on the track with other cars imo. there's plenty of threads on this that will explain it better than I'm doing it lol.

10-20-2011, 09:03 PM	#145 (permalink)
DarkZide Enthusiast Member Join Date: May 2010 Location: TN Posts: 291 Drives: 2010 370z BC M6 Rep Power: 15	I can see it now that I see the shape of the tank, it looks prone to pooling in the lower parts or not being able to flow back over the middle part if its to one side. Would still seem hard to do with 9/10s but i could see it at about 60% or less