Major Track Faults of the 370

Shamu · 02-14-2011, 11:39 PM

Quote:

Originally Posted by spearfish25

The problem with weight reduction in the Z is that it's much easier to remove it from the rear than the front. The fuel tank is under the parcel trays behind the seats...prime weight position. Someone needs to invent a radiator mounted, fascia shaped helium reservoir to provide some buoyancy in the front.

I dont know stock battery can be relocated to rear, lightweight flywheel and clutch, lightweight front brakes, Lightweight radiator, few more bits.

travisjb · 02-15-2011, 12:04 AM

The solution I am using will set you back $800 or so. It allows me to get down to about 5-7 gallons on race slicks in moderate right hand turns... I'm not sure if / how it would hold up in a long turn like the final turn at Sebring, but clearly better than stock... the modification involves placing two pickup pumps in the tank, one rear center and one drivers side - both feed the pax side OE pump... this arrangement has no penalty in NASA scoring etc b/c it uses the stock primary pump... benefit is 50+ lbs of weight and lower chance of fuel cut out... the guy who sold it to me is a racer and small business owner (alarm installations) and he would like to do more of these mods... he's not a sponsor here so PM me for more info... I owe him feedback and photos - the goal is to optimize the setup so we can get down to 1-2 gallons... more R&D required

Mike · 02-15-2011, 08:36 AM

track season is too soon upon me to do that this year. Maybe next fall or winter.

RCZ · 02-15-2011, 10:27 AM

^ yeah and I still have no brakes

Wait...its track season all year here.

cossie1600 · 02-15-2011, 10:31 AM

there are many cars with u shaped gas tanks, how do they get away from the problem? i have never seen the oe pump pickup point, is there anyway to change or extend it

spearfish25 · 02-15-2011, 11:51 AM

^I've tried looking through the service manual, but it appears the fuel pump just sits in the tank and picks up the fuel directly. I'm amazed there isn't a hose from the pump that snakes around the tank bottom.

If one could hook up a hose to the pump inlet, a series of float ball-valves in a rigid tube along the bottom would solve the problem. Think of a long horizontal PVC pipe (but PVC may not be fuel system appropriate) with holes in the top. At each hole would be a floating ball in a small 'cage'. If the fuel level has the pipe submerged, all the balls would float and the entire pipe would be used for fuel pickup. If you turn hard with a low fuel level, any exposed ball-valves would close and seal (ball would seat in the pipe without the fuel for buoyancy) and the pipe would use any open ball valves (portions submerged in fuel) for inflow.

travisjb · 02-15-2011, 12:10 PM

Chris, makes sense... look these guys up and ask for my bud Tony Lisa PATENT IT! - The Law Offices of Steven G. Lisa, Ltd. - Patent Procurement, Enforcement, Licensing & Litigation

they do IP for racing applications... quick before someone takes your idea!

Quote:

Originally Posted by spearfish25

^I've tried looking through the service manual, but it appears the fuel pump just sits in the tank and picks up the fuel directly. I'm amazed there isn't a hose from the pump that snakes around the tank bottom.

If one could hook up a hose to the pump inlet, a series of float ball-valves in a rigid tube along the bottom would solve the problem. Think of a long horizontal PVC pipe (but PVC may not be fuel system appropriate) with holes in the top. At each hole would be a floating ball in a small 'cage'. If the fuel level has the pipe submerged, all the balls would float and the entire pipe would be used for fuel pickup. If you turn hard with a low fuel level, any exposed ball-valves would close and seal (ball would seat in the pipe without the fuel for buoyancy) and the pipe would use any open ball valves (portions submerged in fuel) for inflow.

spearfish25 · 02-15-2011, 12:58 PM

Thanks. I sent them an email. Who knows if my idea even works though. Yet another project to undertake during a vacation!

I'd happily take no credit or financial gain for the idea if someone was able to make it work. And maybe provide a finished product for me too...

cossie1600 · 02-15-2011, 05:46 PM

I had a little time today. It looks to me the problem lies in the design of the fuel tank. Since the fuel tank is U shape and the fuel pump is on the right side, it makes sense that we get cut out on hard right hander as all the fuel jumps to the left side. I don't know if Nissan installed a baffle plate inside the tank. If they did, they have a hole drilled too big or too low and therefore allow the fuel to leak to the left side. The simple fix would be to drill additional holes that are smaller at a higher location and put a one way fuel check valve in the stock location. If they didn't have one in, it wouldn't surprise me if they come up with a new gas tank design in the 2011 cars. Cars like RX-7 had done the same thing in the past during the mid-year upgrade.

http://www.courtesyparts.com/images/z34/z34_172-1.gif

Ricochet48 · 02-16-2011, 10:25 PM

This issue is very...interesting.

I've been tracking my RSX-S consistently for 3 years now at the Autobahn (IL), Gingerman (MI), and will be at Road America (WI) this summer. I raced it with just an intake, struts & shocks at first. Then I got sways & braces. Finally I got SS lines, pads, and 550F brake fluids.

Even before the brake modifications, I never had my brake pedal go down to the floor or anything like other drivers. I also never had fuel starvation issues I believe. Sure, I ran out of gas quick, but I went WOT a lot (esp with only an NA 2.0).

From what I've been gathering, the Z not only needs an oil cooler, but now also has gas starvation issues? I plan on getting a Z down the road and tracking it, so this is not good news...

I would also upgrade the brake fluid tho and from the sound of it start with Stillen sways (and eventually get KWv3s)

cossie1600 · 02-16-2011, 10:30 PM

200HP vs 300HP, big difference

BGTV8 · 02-17-2011, 12:06 AM

I have been tracking my Z34 since new (May 2009) and hav not had fuel starvation. The circuit that is hardest on the car is Philip Island where T1 is a lift-dab and turn-in at 210kph followed by 5 seconds WOT to the brakingpoint for T2 - and even with the tank at <50% full have never had the engine stumble. T3 is flat in 5th to the left - same deal.

T7 (Lukey Heights) is a firm brake, downshift to 4th and hold near peak revs in a rising left-hander that crests and fall away from you .. again, no fuel-related stumble (but I have spun as the suspension goes lght and unloads which is "interesting").

The corner coming onto the straight is WOT in 5th turning to the left and again, I have never had a fuel-realted stumble.

My Z34 is RHD (as we drive on the correct side of the road in Oz - a bit unusual but we like it) but I am sure that this is not material.

It is true that I usually drive at track days on the top half of the tank, but I have certainly run the tank down to 30% full with fuel starvation.

ChrisSlicks · 02-17-2011, 08:33 AM

Quote:

Originally Posted by BGTV8

I have been tracking my Z34 since new (May 2009) and hav not had fuel starvation. The circuit that is hardest on the car is Philip Island where T1 is a lift-dab and turn-in at 210kph followed by 5 seconds WOT to the brakingpoint for T2 - and even with the tank at <50% full have never had the engine stumble. T3 is flat in 5th to the left - same deal.

T7 (Lukey Heights) is a firm brake, downshift to 4th and hold near peak revs in a rising left-hander that crests and fall away from you .. again, no fuel-related stumble (but I have spun as the suspension goes lght and unloads which is "interesting").

The corner coming onto the straight is WOT in 5th turning to the left and again, I have never had a fuel-realted stumble.

My Z34 is RHD (as we drive on the correct side of the road in Oz - a bit unusual but we like it) but I am sure that this is not material.

It is true that I usually drive at track days on the top half of the tank, but I have certainly run the tank down to 30% full with fuel starvation.

Is the filler nozzle still on the RH side in the Oz spec cars?

Phillip Island is mostly left handers so with the fuel pickup on the right those aren't a problem. T1 might not give you problems as the radius isn't super tight hence the duration isn't that long. You need to be fully loaded turning right at close to 1G for a few seconds to experience the problem. The higher the G load the quicker it happens. With slicks on I can only get down about 2 dots before I'll start having issues on some tracks.

travisjb · 02-17-2011, 10:23 AM

Agree, at the limit T1 at Philips should produce fuel starvation... do you have a way to measure lateral G-loading? also, are you simply coasting from t1 to t2?

other than that, the only two right handers are essentially hairpins, neither of which should cause fuel starvation... do they have any clockwise sessions there? then you'd really get to experience all the fun you've been missing... haha

BGTV8 · 02-17-2011, 05:04 PM

T1 in a Z34 is just a lift, turn in and back to WOT. I have data logging from my race car which shows 1.3G lateral (this car runs 290/625R16 Dunlop SS12 slicks) and a guess for the Zed with Dunlop Direzza's whould be around 65% of what the race car sees - so it will be close to 1G, but wouldn;t be over it.

The fuel pickup is in the same spot, so maybe I'm just lucky with the circuits I run on here.

02-15-2011, 12:04 AM	#2 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	The solution I am using will set you back $800 or so. It allows me to get down to about 5-7 gallons on race slicks in moderate right hand turns... I'm not sure if / how it would hold up in a long turn like the final turn at Sebring, but clearly better than stock... the modification involves placing two pickup pumps in the tank, one rear center and one drivers side - both feed the pax side OE pump... this arrangement has no penalty in NASA scoring etc b/c it uses the stock primary pump... benefit is 50+ lbs of weight and lower chance of fuel cut out... the guy who sold it to me is a racer and small business owner (alarm installations) and he would like to do more of these mods... he's not a sponsor here so PM me for more info... I owe him feedback and photos - the goal is to optimize the setup so we can get down to 1-2 gallons... more R&D required __________________ 2009 370Z #104 For Sale

02-15-2011, 08:36 AM	#3 (permalink)
Mike The370Z.com Sponsor Join Date: Jun 2009 Location: Loganville, GA Posts: 5,944 Drives: 370z Rep Power: 2188	track season is too soon upon me to do that this year. Maybe next fall or winter. __________________ NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z Porsche: 93 968 / 23 Macan GTS / 93 968

02-15-2011, 11:51 AM	#6 (permalink)
spearfish25 A True Z Fanatic Join Date: Mar 2009 Location: Naples, FL Posts: 4,117 Drives: to work Rep Power: 1858	^I've tried looking through the service manual, but it appears the fuel pump just sits in the tank and picks up the fuel directly. I'm amazed there isn't a hose from the pump that snakes around the tank bottom. If one could hook up a hose to the pump inlet, a series of float ball-valves in a rigid tube along the bottom would solve the problem. Think of a long horizontal PVC pipe (but PVC may not be fuel system appropriate) with holes in the top. At each hole would be a floating ball in a small 'cage'. If the fuel level has the pipe submerged, all the balls would float and the entire pipe would be used for fuel pickup. If you turn hard with a low fuel level, any exposed ball-valves would close and seal (ball would seat in the pipe without the fuel for buoyancy) and the pipe would use any open ball valves (portions submerged in fuel) for inflow. __________________ 2013 Cadillac V-Wagon, RIP Z

02-15-2011, 12:58 PM	#8 (permalink)
spearfish25 A True Z Fanatic Join Date: Mar 2009 Location: Naples, FL Posts: 4,117 Drives: to work Rep Power: 1858	Thanks. I sent them an email. Who knows if my idea even works though. Yet another project to undertake during a vacation! I'd happily take no credit or financial gain for the idea if someone was able to make it work. And maybe provide a finished product for me too... __________________ 2013 Cadillac V-Wagon, RIP Z Last edited by spearfish25; 02-15-2011 at 01:01 PM.

02-16-2011, 10:25 PM	#10 (permalink)
Ricochet48 Base Member Join Date: Dec 2008 Location: Darien, IL Posts: 117 Drives: 06 Acura RSX Type S Rep Power: 18	This issue is very...interesting. I've been tracking my RSX-S consistently for 3 years now at the Autobahn (IL), Gingerman (MI), and will be at Road America (WI) this summer. I raced it with just an intake, struts & shocks at first. Then I got sways & braces. Finally I got SS lines, pads, and 550F brake fluids. Even before the brake modifications, I never had my brake pedal go down to the floor or anything like other drivers. I also never had fuel starvation issues I believe. Sure, I ran out of gas quick, but I went WOT a lot (esp with only an NA 2.0). From what I've been gathering, the Z not only needs an oil cooler, but now also has gas starvation issues? I plan on getting a Z down the road and tracking it, so this is not good news... I would also upgrade the brake fluid tho and from the sound of it start with Stillen sways (and eventually get KWv3s) __________________ I feel like some RWD and torque!

02-15-2011, 10:27 AM	#4 (permalink)
RCZ A True Z Fanatic Join Date: Nov 2008 Location: Miami Posts: 6,403 Drives: '09 370Z Rep Power: 1120	^ yeah and I still have no brakes Wait...its track season all year here.

02-15-2011, 10:31 AM	#5 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 32	there are many cars with u shaped gas tanks, how do they get away from the problem? i have never seen the oe pump pickup point, is there anyway to change or extend it

02-15-2011, 05:46 PM	#9 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 32	I had a little time today. It looks to me the problem lies in the design of the fuel tank. Since the fuel tank is U shape and the fuel pump is on the right side, it makes sense that we get cut out on hard right hander as all the fuel jumps to the left side. I don't know if Nissan installed a baffle plate inside the tank. If they did, they have a hole drilled too big or too low and therefore allow the fuel to leak to the left side. The simple fix would be to drill additional holes that are smaller at a higher location and put a one way fuel check valve in the stock location. If they didn't have one in, it wouldn't surprise me if they come up with a new gas tank design in the 2011 cars. Cars like RX-7 had done the same thing in the past during the mid-year upgrade. http://www.courtesyparts.com/images/z34/z34_172-1.gif

02-16-2011, 10:30 PM	#11 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 32	200HP vs 300HP, big difference

02-17-2011, 12:06 AM	#12 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,516 Drives: 09 Nissan 370Z M6 Rep Power: 39975	I have been tracking my Z34 since new (May 2009) and hav not had fuel starvation. The circuit that is hardest on the car is Philip Island where T1 is a lift-dab and turn-in at 210kph followed by 5 seconds WOT to the brakingpoint for T2 - and even with the tank at <50% full have never had the engine stumble. T3 is flat in 5th to the left - same deal. T7 (Lukey Heights) is a firm brake, downshift to 4th and hold near peak revs in a rising left-hander that crests and fall away from you .. again, no fuel-related stumble (but I have spun as the suspension goes lght and unloads which is "interesting"). The corner coming onto the straight is WOT in 5th turning to the left and again, I have never had a fuel-realted stumble. My Z34 is RHD (as we drive on the correct side of the road in Oz - a bit unusual but we like it) but I am sure that this is not material. It is true that I usually drive at track days on the top half of the tank, but I have certainly run the tank down to 30% full with fuel starvation.

02-17-2011, 10:23 AM	#14 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	Agree, at the limit T1 at Philips should produce fuel starvation... do you have a way to measure lateral G-loading? also, are you simply coasting from t1 to t2? other than that, the only two right handers are essentially hairpins, neither of which should cause fuel starvation... do they have any clockwise sessions there? then you'd really get to experience all the fun you've been missing... haha __________________ 2009 370Z #104 For Sale

02-17-2011, 05:04 PM	#15 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,516 Drives: 09 Nissan 370Z M6 Rep Power: 39975	T1 in a Z34 is just a lift, turn in and back to WOT. I have data logging from my race car which shows 1.3G lateral (this car runs 290/625R16 Dunlop SS12 slicks) and a guess for the Zed with Dunlop Direzza's whould be around 65% of what the race car sees - so it will be close to 1G, but wouldn;t be over it. The fuel pickup is in the same spot, so maybe I'm just lucky with the circuits I run on here.

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