Custom Fuel Injection

Dan · 08-06-2003

One of the members in our Auto-x club is a race car fabricator. He mentioned that he set up custom fuel injection systems. He happened to have his Nissan Silvia outside and offered to show us his work. The intake is a custom built aluminum unit, it uses 1 3/4" runners and about a 4" round plenum. He attaches a Nissan 240sx throttle body, bosses the runners and cutom builds the fuel rail, custom connector to the MAF and bends the intake tube to place the filter in a good cool spot. He uses the injectors, computer and O2 sensor from the 240sx as well. He has built several of the cars for our club members and put cages in others, built custom headers and intakes for other people, etc... so I'm confident in his fabrication skills. His Silvia ran extremely well and he said with very little tuning the plugs were perfect.

He said he could build one using basically the same nissan parts and a custom intake, then do the initial tuning for me for about $1000. Does this sound like a reasonable amount? The only problem I have is that the computer is only tunable to a certain degree, and it is used equipment that I could pick up at the pull and save for under $50 with the exclusion of the custom intake and fuel rail.

He also builds roll cages and said his normal price is about $1000 for a good 8 or 10 point (he would have to see the car to determine the best setup) that is SCCA road race legal. I have seen his cages and they are works of art. They are very tight to the body and the welds are nice and fluid. I'm not sure his price on headers, but they would probably be a few hundred.

GT-Freak · 08-06-2003

$1000 is a little high for a cage. It's probably reasonable IF he's putting in extra bends to fit around the dash and the contours, and/or removing and reinstalling the seats, carpet and interior. The sanctioning body sets the rules for the cage: number of points, material, reinforcement and side protection. Many use SFI standards.

Custom EFI with custom intake and custom rail installed for $1000. Wow. That's a deal. Even if some parts are salvage. Lots of places charge $60 an injector bung welded on. At a pick-a-lot yard getting the harness, computer, injectors, throttle plate, all the sensors and misc. parts costs a lot more than $50. Import car yards cost more than domestic. I'd test every sensor before installation, as many cars run with broke sensors. Use new/remanufactured injectors. This really beats a stock Solex.

Nissan Altima and 240SX share many parts. Altima might be cheaper to get as there's a bazzillion (#1 selling car in the US for the 1990's decade). These (Altima and SX) use 16 degrees of initial timing and run up to 6500 rpm. They'll handle about any cam that can be used with power brakes. Not much tuning required.

RallyBob · 08-06-2003

Originally posted by GT-Freak
$1000 is a little high for a cage. It's probably reasonable IF he's putting in extra bends to fit around the dash and the contours, and/or removing and reinstalling the seats, carpet and interior.

Actually, $1000 is dirt cheap for an SCCA legal cage for road racing or rally use. A quality cage from DOM tubing usually starts at $1500 and can climb to $3500-$4000 easily. Figure 40-60 hours of labor plus $300-$500 just for the tubing.

Bob

oldopelguy · 08-06-2003

While I do appreciate the art of a fabricated intake manifold, you might get the same effect at a substantially lower $ by modifying a stock Opel EFI manifold. Add new throttle, if necessary, injectors, and the rest of the electronics and you might be great on a lower budget.

Just one idea, but if it worked well for you the rest of us would love to get the details...

RallyBob · 08-06-2003

Originally posted by oldopelguy
While I do appreciate the art of a fabricated intake manifold, you might get the same effect at a substantially lower $ by modifying a stock Opel EFI manifold.

Agreed. Besides, unless the rest of the engine has been developed (headwork, cam, compression), you will likely reap very little benefit from the custom intake, if any at all. Large plenums, and large diameter short runners are fine for high rpms or large displacement engines, but would kill the torque on a 1.9 or 2.0 Opel (very short stroke engines).

Bob

GT-Freak · 08-06-2003

I didn't know SCCA cages cost that much. Ouch. There must be a bunch of side protection. I'm used to NHRA cages. I can get an NHRA tube chassis (for slower cars) with 12 point cage for about $1500 custom made. I talked to a frame shop last week. Alston (near Chicago) sells them for $1799 (4-link axle prep). These are mild steel, add $1000 for chrome-moly steel.

I also like the stock manifold idea. Mild porting will help. And it doesn't clearance issues. It's a good first step before paying extra for the intake. Although custom intakes look great.

Dan · 08-07-2003

RallyBob, do you still have that extra FI manifold laying around that we talked about several months ago? I bet if I could get that and the parts he would boss it and do the tuning real cheap.

He is very fast with his cages, he just seems to have a natural talent for the bending. I talked to a few of his customers and they said they watched him work and it was amazing how quick and precise he put them together.

markandson · 09-14-2005

I am working on a custom EFI system for my 2.2. I searched threads looking for a recommended MAF unit that will fit into the same spot where the AFM used to be in a stock EFI system, but can't find any info. Does anyone know which one will work? I am planning on running a Megasquirt with it.
Thanks.

RallyBob · 09-14-2005

Originally Posted by markandson

I am working on a custom EFI system for my 2.2. I searched threads looking for a recommended MAF unit that will fit into the same spot where the AFM used to be in a stock EFI system, but can't find any info. Does anyone know which one will work? I am planning on running a Megasquirt with it.
Thanks.

No MAF is used with a Megasquirt. It will be mapped via rpm values, TPS voltage, and MAP sensor values.

markandson · 09-14-2005

Thanks Bob, obviously I have alot to learn in order to make this thing a reality. The good news is that MAFs are pretty expensive and if I don't need one, that's a plus.

08-06-2003	#1 (permalink)
Dan Member Join Date: Mar 2002 Location: Spokane, WA Posts: 241	Unanswered: Custom Fuel Injection One of the members in our Auto-x club is a race car fabricator. He mentioned that he set up custom fuel injection systems. He happened to have his Nissan Silvia outside and offered to show us his work. The intake is a custom built aluminum unit, it uses 1 3/4" runners and about a 4" round plenum. He attaches a Nissan 240sx throttle body, bosses the runners and cutom builds the fuel rail, custom connector to the MAF and bends the intake tube to place the filter in a good cool spot. He uses the injectors, computer and O2 sensor from the 240sx as well. He has built several of the cars for our club members and put cages in others, built custom headers and intakes for other people, etc... so I'm confident in his fabrication skills. His Silvia ran extremely well and he said with very little tuning the plugs were perfect. He said he could build one using basically the same nissan parts and a custom intake, then do the initial tuning for me for about $1000. Does this sound like a reasonable amount? The only problem I have is that the computer is only tunable to a certain degree, and it is used equipment that I could pick up at the pull and save for under $50 with the exclusion of the custom intake and fuel rail. He also builds roll cages and said his normal price is about $1000 for a good 8 or 10 point (he would have to see the car to determine the best setup) that is SCCA road race legal. I have seen his cages and they are works of art. They are very tight to the body and the welds are nice and fluid. I'm not sure his price on headers, but they would probably be a few hundred.

08-06-2003	#4 (permalink)
oldopelguy Have Opel, Will Travel Join Date: Mar 2002 Location: Saint Michael, MN Posts: 1,727 Logbook Entries: 3 Provided Answers: 2	possibility While I do appreciate the art of a fabricated intake manifold, you might get the same effect at a substantially lower $ by modifying a stock Opel EFI manifold. Add new throttle, if necessary, injectors, and the rest of the electronics and you might be great on a lower budget. Just one idea, but if it worked well for you the rest of us would love to get the details...

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08-06-2003	#2 (permalink)
GT-Freak Member Join Date: Jun 2003 Location: Kansas City, MO Posts: 174	$1000 is a little high for a cage. It's probably reasonable IF he's putting in extra bends to fit around the dash and the contours, and/or removing and reinstalling the seats, carpet and interior. The sanctioning body sets the rules for the cage: number of points, material, reinforcement and side protection. Many use SFI standards. Custom EFI with custom intake and custom rail installed for $1000. Wow. That's a deal. Even if some parts are salvage. Lots of places charge $60 an injector bung welded on. At a pick-a-lot yard getting the harness, computer, injectors, throttle plate, all the sensors and misc. parts costs a lot more than $50. Import car yards cost more than domestic. I'd test every sensor before installation, as many cars run with broke sensors. Use new/remanufactured injectors. This really beats a stock Solex. Nissan Altima and 240SX share many parts. Altima might be cheaper to get as there's a bazzillion (#1 selling car in the US for the 1990's decade). These (Altima and SX) use 16 degrees of initial timing and run up to 6500 rpm. They'll handle about any cam that can be used with power brakes. Not much tuning required.

08-06-2003	#6 (permalink)
GT-Freak Member Join Date: Jun 2003 Location: Kansas City, MO Posts: 174	I didn't know SCCA cages cost that much. Ouch. There must be a bunch of side protection. I'm used to NHRA cages. I can get an NHRA tube chassis (for slower cars) with 12 point cage for about $1500 custom made. I talked to a frame shop last week. Alston (near Chicago) sells them for $1799 (4-link axle prep). These are mild steel, add $1000 for chrome-moly steel. I also like the stock manifold idea. Mild porting will help. And it doesn't clearance issues. It's a good first step before paying extra for the intake. Although custom intakes look great.

08-07-2003	#7 (permalink)
Dan Member Join Date: Mar 2002 Location: Spokane, WA Posts: 241	RallyBob, do you still have that extra FI manifold laying around that we talked about several months ago? I bet if I could get that and the parts he would boss it and do the tuning real cheap. He is very fast with his cages, he just seems to have a natural talent for the bending. I talked to a few of his customers and they said they watched him work and it was amazing how quick and precise he put them together.

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