Went to the local races yesterday in our hometown and made the cardinal mistake of not filling the car with fuel until it was spilling out. In the past I have found that i have to run a COMPLETE full tank of fuel and then it will not suck air. REDICULOUS.

During the spring I bought everything I needed to build a surge tank, but just have not had the time to complete the project. You know how that goes.

Yesteday at the races I was the fastest car there and there are some pretty heavy hitters (BIG $$ cars) that come there to show their stuff. However none of them can hook like the good old vette. Even I spin but have the 1-2 shift down where I minimize my spinning and pull ahead enough they can't catch me on the top end. Some get damn close but I usually always pull it off.

I was racing a buddy and while good buddies I hate to loose to him. Sure enough I got the lead on him and then about 1/2 track my car started to loose power and surge. He pulled a fender on me after I left off to check all guages etc and then I eases back on the throttle and all was ok. Next run the car ran great....then again did it again about 1/2 track. It has to be the fuel pump sucking air and I have HAD IT with this crappy fuel system in these cars.

As such, I am going to be putting a 15gal fuel cell in place of the stock tank with a sending unit so my gas guage works again. It works now but the pickup is so badly bent from the violent takouts it reads full with only 5 gals of fuel in it.

Does anyone know how much the stock tank weights? I suppose that I will know soon enough but I like to get the details as I can do some calculations to determine how much I should gain in ET from combined weight savings. I should be able to gain at least .075 which will put me in the 9s in the better weather.

Anyone with tips on bumper removal or photos of their fuel cell installed I would greatly appreciate it.

I will be fabricating and tig welding all the framing from aluminum to keep everything as light as possible.

 

Jesse, about all I can help with is the rear bumper removal. It is not a fun job since a lot of it is working blind. Remove the license plate and reverse lights. Going in through there you can feel the 10mm nuts on the taillights, there are two on each light. Once you get the lights out you can feel the 7 mm screws along the bumper/quarter panel seam. Once you get all these out the rest are a bit easier. If I recall you can go up from the bottom to remove the ones along each side, if not then you can remove the rear wheelwell and get at them that way. You will have to at least take half the screws out of the wheelwell anyway, the ones that are attached to the bumper. No idea on tank removal but it is right there once the bumper is off so it shouldn't be too bad.

 

Could you just sump the tank?
http://www.competitionengineering.co...?CatCode=10070

 

Thanks midnight for the nice instructions.....that helps.

Yeti - we used one of those sumps on the chevelle for a while, but they are intended for very flat tanks - our tank is very round so I doubt it would be very easy to adapt. The other thing is our tanks have a bladder in them (plastic) so if you welded on it the plastic would melt and probably cause a multitude of problems.

I am going to be going to a fuel cell and have it fill through the existing fill cap. Nobody should be the wiser that is a sump is back there.

 

your vette is one of very few production cars that comes with a REAL fuel cell (steel can plus a full rubber bladder)... oem pick-up location was selected for universal application, aka "one size fits none"...add an ATL duck-foot pick-up/hose (available from most circle track vendors for abt $70) to your pump (you'll need to cobble up an adapter) and put the "foot" at the rear of the tank for drag use but "sit" for a few seconds after burnout brake stop(fuel will slosh to front of tank during braking, away from duckfoot):

http://www.atlinc.com/US/download.ph...ingDevices.pdf

to reduce fuel slosh significantly, spend abt $150 for a set of foam blocks for inside the tank...these can be squeezed down and inserted thru the oem vette tank pump/sender hole...released inside the tank, the individual blocks immediately regain their original size/shape, can be "arranged" to leave a space for the fuel sender free to function, and if arranged to put slight pressure block-to-block will maintain position quite well.

 

If it's the Vette in the video in your sig, looks like you probably need to change out the bumper cover anyways

 

SloRvette built a sump tank for a C4 a while back.

When you back in NE I can introduce you.

 

With your fabrication skills you could also remove the big **** piece of alum that the tank sits on and that the rear panels brace off.

 

Once the bumper cover is off,exhaust lowered or removed,you have to loosen that back alloy tank frame it sits on and lower it down so the tank can come out and clear the rear deck panels.
The long bolts are on each side of that tank frame.

Also,Have to disconnect the cables that hold the tank to the sway bar brackets or etc back there.I believe there are 2 cables and straps that need to be loosened or come off.You will see,real easy.Its been a while for me But I think its along those lines.Didnt even need the manual to do it.Just go by eye and see whats in the way.

 

Thanks guys....I will keep you posted and get some photos of the install etc.

Keep the ideas and photos if anyone has them coming.

 

Hi, I had the same problem. So I put in a 5 gal fuel cell and an Aeromotive fuel pump. The old tank with the pump and fuel pickup weighed about 32lbs. I lost 75 pounds after the swap but I guess most of that was the 10 gallons less of fuel. The biggest thing I noticed was the consistency between runs. Now it's easy to get the same amout of fuel in it. I say do the fuel cell. You'll like it.

Doug

 

Thanks man for the photos. Yeah i fugure I should be able to gain an entire .1sec with the weight loss of the tank and all the fluid that I normally run. Not to metioned what other detrimental things might be happening with the fuel delivery I am not even aware of like inconsistency etc. All it takes is a fraction of a second of pressure loss and it could really be hosing things up.

Normally I run a FULL tanks at 18 gals x ~6.0 lbs/gal = 108lbs!

If I only run 5 gals when racing = 78lbs savings. Then whatever the tank etc all weighted less the weight of the cell/pump etc needed to revamp the system. should be some good weight savings.

Done deal.

One other question is it looks like you have a good amount of distance between the cell and your fill area. But in a later photo it looks like you have it right close to the fill area or is that an illusion? Any reason not to make it right close to the fill area? I imagine that the weight being up as high as possible would be better from everything I have known before.

Also i do not see a ground wire on your fill area!

Thanks again.

 

Hi, the filler cap is lower then it looks in the last photo. It hasn't been any big deal. I just use a longer funnel to filler it up. I mounted the tank low to keep the center of gravity as low as I could in the car.

As far as the grounding wire goes. No there isn't one. The tank is grounded to the frame. The cap and filler area is plastic. I'm not sure if it's right or not but according to the NHRA rule book, it says. Non-metallic fuel cells or tanks must be ground to the frame. I don't see anything about aluminum fuel cells. The tech people haven't said anything either. If it's wrong I'll put one on.

Doug.

 

Jesse, I know it's a long shot,
but I have seen the dragster guys put a small tank up front ahead of the engine and let g-forces "push" the fuel towards the engine. Granted, it's a different kind of set-up, but creative fabrication could make something work. ???

Possibly leave the stock tank system in place, and have some kind of a method to switch between the two. Have the stock tank almost empty for drag runs and use it normally for daily driving duties.

???