Have a look at section 8.2 in this document:

http://www.holley.com/data/Products/...99R10179-2.pdf

It looks like the injectors stick up a good 4" above the top of the TB.

 

Thanks for the link. I can see what you are talking about as far as the injectors sticking up. But, it would seem to me that the actual main body of the unit is somewhat shorter than the Demon carb that I have on there now. I think that the injectors would just project into the air cleaner.

The more I sit here and look at gas prices, and the more I think about how much driveablity I would gain with a unit like this, the more I think that I might bite the bullet and give Summit a call. If it doesn't fit I can always return it I suppose.

 

Yes, the main body is lower than a holley. I think about 1".

 

Thanks for all the replies so far guys, this has been a very interesting thread so far. Most of the aftermarket systems seem to expensive, I can buy an LS1 with wiring and computer for the price of some of them, and I don't have the time to engineer a home made system using Gm parts or aftermarket. The only system that seems reasonably priced and relatively easy to install is the Holley C950 TBI kit:

http://store.summitracing.com/defaul....asp&x=13&y=14

I know this system will offer better cold starting and drivability over a carb, but will it really increase my gas mileage enough to be worth it? TBI seems old school to me compared to MPFI, it was first gen FI technology, wasn't it?

 

Yeah, I got all the usual - Big 'ol K&N, 52mm TB, machined with airfoil in place, ported plenum, matched to SLP runners, matched to intake. All on top of ZZ4 crate with a chip burned by yours truly. Backed by well-built 700R4.

Fevre - thanks for your input too !

I'm thinking I'll stick with FI. I'm in this far, why not. And the mileage with the 700R4 is great. In fact, this winter I'm dumping my 3:08's out of the back....

 

so we basically got the same thing but i have 3.70's,im getting 18-22 mpg about as long as i dont stay in the throttle too much

 

Your link is to the MPFI setup. According to your post I think you meant to link to the TBI setup.

 

ooops! Here is the right link

http://store.summitracing.com/defaul...h.asp&x=37&y=6


what do the FI gurus think of this?I know this system will offer better cold starting and drivability over a carb, but will it really increase my gas mileage enough to be worth it? TBI seems old school to me compared to MPFI, it was first gen FI technology, wasn't it?

 

I'm no guru, but if your going to get this you might as well stick with a carb.

Edit: Read TBI as TPI. TBI is definitely old school though. If you're going to go EFI then go all the way.

 

Yep, with the 3:08's, I have to pull it out of OD if I'm going much slower than 45-50 mph. I'm going a little conservative with 3:55's.
What are your ET's like ?

 

I know a guy in a local club that has a Holley TBI setup on his C3 and it works great. It really increased his fuel economy over the carb.

If you don't have time to mess with putting your own system together, I don't think that it's a bad idea.

For each of the folks that do it themselves, I'm sure there's a dozen that have a box of parts in the garage...

I'll have to add though that you could buy the TBI setup and then get the megasquirt controller later to do more....

Get wrenchin'

 

I would have to disagree with you here. I think that TBI is a HUGE improvement over a carb, although admittedly it is at a slight disadvantage to full blown MPFI.

I would like to hear from some more people that have installed TBI units on their cars. There has to be some more out there.

 

Me too.Is anyone here using a TBI system?

 

Maybe we should spin this off into a new post. Such as "Who is using Throttle Body Injection?" Whadda ya think?

 

I am running the 950 TBI on my 1980. I use the stock air cleaner, and it fits under my stock hood with room to spare.
It was very easy to install but it does take some planing. You will have to have a larger fuel return line than the stock line. What I did was to use the stock 3/8" fuel delivery line as my return line and ran a whole new 1/2" line to be my new delivery line. I put a sump in the bottom of my tank and mounted the fuel pump and filters where my spare tire mount used to be. The pump and filters are mounted right to the bar that holds the fuel tank in the car.
The computer went in the glove box (since my 1980 had one) but I am sure you can find room behind your map pocket to mount it.
The wiring is pretty basic and instructions are simple to follow.

By the way, on a recent trip, my 1980 with TBI and overdrive used 8.5 gallons of fuel to travel the same distance that another club member in a C5 traveled and he used 11.5 gallons. I get around 25 - 28 on the highway at 80 mph.
The car starts right away. It never coughs, burps or belches and has throttle response so crisp that I occasionally bang my head on the halo bar because I forget how fast the car can launch.

 

It's a great kit! See my reply above.

Get the 700 CFM model. No need for the 900 CFM unless you are running a big block or serious HP - but then you wouldn't be looking for a way to save fuel then.

 

I have done several carb to TPI and love the TPI. I had a 427 smallblock and now have a 406 small block. It is in my 84 TA. I use TPIS runners, stock plenum (port the hexx out of it) there is a lot you can remove from the inside. I have a BBK 58mm T.B. slp roller cam, vortec heads with 2.02-1.90 valves and headers. The motor will pull to 6800 with no trouble. I have a xxxx165 computer with a custom chip (MAF). I'm in the procress of getting the parts to change my slug 81 vette over to TPI. I want to drive the vette more and the TPI will give me much better gas milage. It should give me much better end power too. I love the vette, there is nothing like driving a vette. I have not checked to see if it will clear the hood. I know from my other setups TPI takes up 9.75 inches from the bottom where the intake mates to the block in front to the top of the plenum. If your vette is factory stock save everything (thats what I'm doing) if you sell it down the road it helps keep its value and you can change back if you wish to. The only problem with the vette change is the fuel tank pickup. F.I. draws a lot of fuel and when the gas gets low it will suck air. If you read other posts you will see others have the same problem.
Just my 2 cents worth.

 

BSeery-

How many hours do you think that it took you to do the install?

 

Very hard to tell. I was also re-doing the sound deadening under my carpet and a few other things at the same time. I had the car apart for weeks on end but sometimes didn't touch it for more than one hour per week.

Figure you need the following:
time to handle the fuel system - 1/2 day min. - 1 day.
electrical - 1/2 day min - 1 day.
under hood work - 1/2 day.
Tuning - 2-3 days.


This isn't like changing the intake and putting a carb on, this is a custom install that involves the entire car.