Petrol tank in the frunk?

Hybridfiat

Hybridfiat

Power costs money, more power cost more money
Has anyone seen an Exxy with a racing tank in the front boot?
I thought it would get the weight distribution better sorted.
Probably cut and shut the former tank space for storage as per the spare tyre area.
Just curious.
 
There have been several race X's that way. I do not have any pics handy, but they've been posted here over the years. Maybe someone has some handy.

I think there is some debate about the effect of this on handling. On the one hand it would help to shift the bias forward more, for a more perfect 50/50 balance. On the other hand it increases the polar moment (hope I used the term correctly). In words I can understand, how far the weight is distributed toward each end vs the middle of the car. More weight further out to the ends (like a dumbell) increases a pendulum effect - it wants to spin out more easily, etc. I'm sure a better explanation will show up shortly.

For a street car consider things like being able to store the top in the frunk.
Just did a quick Google Image search and found these two pics:
FUEL TANK_1440509605_thumb800x600.jpg
IMG_0279.jpg


I plan to mount a small cell in the frunk on my "outlaw" project. But I'm not concerned about handling, tops, or anything practical on that car - it's just for fun.
 
Hybridfiat
I've got a fuel cell in the frunk of my racecar. IMHO moving it there is the single best improvement to handling you can make on your X. It is also the single best way to limit the amount of stuff you can haul around with you.

The stock X is rear weight biased, which makes oversteer a problem. If you have to choose between oversteer and understeer most folks would choose understeer. So anything you can do to reduce oversteer is generally seen as good.

Anytime you move weight around in the car handling will be affected. Moving the weight to the center of the car makes it relatively easier to loose control at the limit (all cars have a limit). But makes it easier to regain control. Moving the weight away from the center of the car helps make the car relativly harder to loose control (oversteer or understeer), but makes it more difficult to regain control. Think of this in terms of a bowling ball (for all the weight in the center), and bar bells (for a car with weight at its ends). It's easy to get the bowling ball spinning, and relatively easy to stop the spinning. The barbells are much more difficult to get spinning, and harder to stop once spinning.

Since we all have to deal with compromises when modifying our cars our choices are limited. If you have scales under each of the tires of your car you can see how moving components around in the car changes the weight distribution. You might find that replacing the passengers seat with the gas tank will help equalize weight distribution. You might find that moving the gas tank to the frunk helps too. Choosing the frunk limits the amount of stuff you can haul around with you, replacing the passengers seat with the gas tank has other limitations.

Be aware that the amount of gas in the tank will change the way the car handles. In my experience, with an 8 gallon fuel cell in the frunk, a full tank makes the car tend to understeer, handling tends to be more neutral as the fuel is burned off.

One other consideration, routing the fuel lines. Make sure you do that safely if you're going to move the gas tank to the frunk.
 
I believe it should also have an effect on braking, allowing the front to have a bigger role in the equation. It would be a boon to have that additional storage in back that you lost in front as well.
 
MikeHynes said:
Hybridfiat
I've got a fuel cell in the frunk of my racecar. IMHO moving it there is the single best improvement to handling you can make on your X. It is also the single best way to limit the amount of stuff you can haul around with you.
One other consideration, routing the fuel lines. Make sure you do that safely if you're going to move the gas tank to the frunk.
Click to expand...

Thanks for the advice.
I hadn't thought about the oversteer issue.
Strange if you consider that I wrote off an Exxy because of 'lift off oversteer'.
I entered a corner at 140kph and thought better of it halfway and backed off the juice. The back swapped ends with the front. I hit the kerb at 110kph left the ground and went into a concave clay bank at 110kph and bounced off. The car was shorter by a whole boot. But I could still open the passenger door.
 
Mid corner dynamics can change drastically with any vehicle if you drastically change input...typically letting off the gas.
When my brother and I were roadracing bikes, he once complained that his bike got squirrely in mid corner when he whacked open the throttle. My advice was "don't do that, roll the throttle on" and it cured the problem!

I imagine this is why street cars have designed in understeer so if the driver gets in over his head the car will at least keep the front end facing forward. Of course modern stability control changes all that as you now have an expert driver looking over your shoulder.
 
Hybridfiat said:
Has anyone seen an Exxy with a racing tank in the front boot?
I thought it would get the weight distribution better sorted.
Probably cut and shut the former tank space for storage as per the spare tyre area.
Just curious.
Click to expand...

Is this for a daily driver/road car or for a track-only car?

If for a daily/road car, sounds like a lot of work and expense for benefits that might be hard to realize at the expense of significant downsides.

All depends on what you're doing with the car.
 
Yup, if just a street car stay with the stock tank. If racing then probably a fuel cell is required.
 
Dan Sarandrea (Phila) said:
Is this for a daily driver/road car or for a track-only car?

If for a daily/road car, sounds like a lot of work and expense for benefits that might be hard to realize at the expense of significant downsides.

All depends on what you're doing with the car.
Click to expand...

Street racer.
It will eventually be used for trackday racing.
I have a standard x1/9 that will stay stock and one that is already modded to take a 160hp Jap motor.
 
Hybridfiat said:
modded to take a 160hp Jap motor
Click to expand...
Remind us what Jap motor you are planning to install in the other X?

I'm doing something similar; I have one X that will remain relatively stock configuration (but customized), and one that will be a track day type build yet still street legal. I haven't decided but the second project may end up without any windows, a cut down windshield, no top, etc. But then it becomes difficult to even store due to the complete exposure (turning the floor pan into a huge rust hole). Wish I lived where large barns are common, to store such toys in.
 
Cut drain holes in the floor and put trash baggies over the seats and you are all set for the rainy season.
 
Dr.Jeff said:
Remind us what Jap motor you are planning to install in the other X?

I'm doing something similar; I have one X that will remain relatively stock configuration (but customized), and one that will be a track day type build yet still street legal. I haven't decided but the second project may end up without any windows, a cut down windshield, no top, etc. But then it becomes difficult to even store due to the complete exposure (turning the floor pan into a huge rust hole). Wish I lived where large barns are common, to store such toys in.
Click to expand...
Its a Toyota Starlet Factory turbo charged 1331cc motor that has been mildly tweaked to deliver a modest 180bhp.
 

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Hybridfiat said:
Its a Toyota Starlet Factory turbo charged 1331cc motor that has been mildly tweaked to deliver a modest 180bhp.
Click to expand...

EP82? Starting from 133hp, not bad.

4E-FTE
The first generation of the 4E-FE was the basis of the 4E-FTE in 1989, which is a turbocharged engine producing 133 hp (99 kW; 135 PS) at 6,400 rpm with 116 lb⋅ft (157 N⋅m) of torque at 4,800 rpm. The 4E-FTE is the most powerful of the E series engines ever produced. It was produced exclusively for the Toyota Starlet GT Turbo (Japan Only) and its successor, the Toyota Glanza V (Japan only). However the 4E-FTE was a very popular conversion engine by enthusiasts for many small Toyota cars such as the Corolla, Tercel, Paseo and Sera which it fit into with standard Toyota parts. The 4E-FTE differs internally from the 4E-FE with its stronger connecting rods, lower compression pistons (reduced from 9.6:1 to 8.5:1) and stronger crankshaft. The cylinder head and valve train are identical to the 4E-FE. The 4E-FTE also features a harmonic damper instead of a normal crankshaft pulley. The turbocharger fitted to the 4E-FTE was Toyota's own CT9 model, which features an internal waste gate and has two modes: low 0.4 bar (5.8 psi) and high 0.65 bar (9.4 psi) boost. The low boost mode is electronically controlled by a solenoid valve and the ECU and the high boost is controlled by an actuator connected to the turbocharger. The 4E-FTE also has a top-mounted, air-cooled intercooler. The 4E-FTE is mated to the Toyota C52 transmission (for the EP82 Starlet GT) and the C56 transmission (for the EP91 Glanza V).
Specs
  • Bore x stroke 74 mm × 77.4 mm (2.91 in × 3.05 in)
  • 8.5:1 compression ratio
I recall another forum member using this set up a long while ago, there were questions about the intercooler on top of the transmission area getting enough air.

It would be great to see more details.

Thanks

Karl
 
Im going to start a dedicated thread when I have a bit more time.
The nominal output is 133hp but I got that at the back wheels after upgrading the turbo.
The intercooler is mounted in place of the carbie fan unit and draws air from a modified side intake.
 
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