cdrod

I need some advice from the more experienced Olds gurus. I was planning on running a frankenstein Quadrajet for my 375 cid stroker build. Here's where the frankenstein part comes in, I wanted to rebuild my '72 era Q-jet with a throttle shaft from a later model carb to make it easier to connect the TV cable for a 200R4 OD trans. The local Q-jet builder wants $400 to build the carb and a wideband O2 gauge will run another $200 plus whatever he will charge to tuning the carb on a chassis dyno. So, I'm looking at $600+ for the Q-jet route.
FiTech just released a 400HP throttle-body EFI system called the GoStreet that sells for $795 and has provision for the TV trans cable hookup. Is this a better direction than the frankenstein Q-Jet?

http://www.jegs.com/i/FITech+Fuel+In...FUiGfgodK1sNoQ

coppercutlass

I would go with the FItech if i had the money

oldcutlass

I think the most knowledgeable on these systems is Mark, Cutlassefi. I'd shoot him a pm.

midrange

I have a Fitech 600hp for my mildly built 455.
I haven't installed it yet as I'm building an in-tank fuel pump/system using a 2010 Camaro fuel pump.
I did a ton of reading on other forums about the Fitech and felt it is exactly what I want/need.

This link here is where I learned the most.
http://www.chevelles.com/forums/89-efi/835633-fitech-efi-fuel-command-center-review-install-w-pics.html


A couple of people there were having some problems with the Fitech Fuel Command Center and went the 'in-tank' route.

edited to add:

I had a Quadrajet on it at first, but I couldn't get it tuned correctly, I even had a friend who knew their way around them and he was stumped on it.
My wife being awesome as she is, watched me reading on the Edelbrock 750's and surprised me with one of them.
The problem was the more I read, the more I found that an 850 would have been a better choice.
I had already installed the 750..... oh well.
Now that I had a good carb, I found that I wasn't getting the fuel needed from the stock replacement 'hi volume' fuel pump.
Both of those issues led me the Fitech.
Figuring another $450+ for the 850, and another couple of hundred for a reliable electric fuel pump/system, put me in range of the FiTech.

olds 307 and 403

The Holley Sniper is a few hundred more and has better tech support. Their "techs" didn't know if you could control a GM HEI in any form, pretty sad. If your going QJet, get a 76-80 core custom for your application, they have advantages over the early carbs

jensenracing77

Is the Q jet good to start with and just needing the shaft changed or are you starting from a core carburetor. It is not that hard to change the shaft if that is all that is needed. Just have to be sure the butterflies are properly aligned on reassembly. I helped a friend change a shaft in one for that same thing. It took me longer to dig through my junk q jets to find a correct shaft than it did to change it out. I will admit, this was 16 years ago but I think I remember it being easy to change.

cutlassefi

Do the Holley Sniper or Terminator. The lack of general knowledge by FITech's own employees would scare the hell out of me.

Mr Nick

I went from a Q-Jet to EFI a few years ago, even my now outdated EZ-EFI (version 1) was still a big step up from the Q-Jet.

The fact that you can get EFI with timing control for a grand (plus fuel system) is amazing.


I also agree with Mark. While the FiTech stuff does sound great, and appears to be selling well, I've been burned enough times by the 'new kid on the block' that I stay with known reliable vendors now. For a few bucks more I'd go with this over FiTech:

http://www.jegs.com/i/Holley/510/550-510/10002/-1

joe_padavano

Swapping the primary throttle shaft to get the TV cable attachment is extremely easy. There's also no way a Qjet rebuild can cost $400 unless that includes recoloring the body. Sure, EFI will be a better choice, but understand the total costs and labor involved. The Qjet solution should be under $200.

olds 307 and 403

Joe mine cost $250 for a rebuild and custom tune, about the cheapest around from Everyday Performance. That included rebushing the secondary throttle shafts. No recolouring/plating and cores add $75 to the price. It is ridiculous what people are asking for used carbs now.

joe_padavano

With the bushing replacements, that's not bad.

oddball

I paid Sparky $400. But that included rebuild, coloring, and modifying primary shaft ($100 itself). And shipping.

The problem with shaft replacement is getting the correct bracket on the correct shaft. Most of the brackets with TV provisions are on E4M carbs, which won't swap into an older 4M carb. I can't recall if M4M shafts work on 4M carbs.
That's why it's common to cut the bracket off your good shaft and graft on a later year bracket. Sparky provides that service, and there are some DIY methods.

I am a huge fan of sticking with a QJet IF you get a good carb and get it tuned well. Some carbs are simply cursed and will not get a good configuration for a given engine, and lots of carbs have been horribly abused over the years. You never know what's going on in the internal passages, and there are a lot of very small modifications on the internals that make huge differences.

I'll readily grant that EFI is easier/quicker to tune and is more consistent (good or bad!). Whether or not the resulting tune is better than an equivalent carb setup is not guaranteed. I totally understand the typical conversion, because getting a carb properly settled down can be a major headache. I have easily 150 hours of tuning in my current carb. That could have been done in a couple of days with EFI.

In general, throttle body injection is not dramatically better than carb. The same drawbacks exist. Integrated ignition control helps, but then it's really down to the level of tuning available in the EFI unit. And the cheaper ones are generally very limited on that front. That's what makes them cheap and easy to set up.

Switching to multiport with full ignition control is a completely different ballgame, but you're talking serious investment and serious tuning.

If you're not prepared to get a carb totally dialed in (my stockpile is 10 parts carbs, one box of misc large hard parts, one reference carb, one stuffed parts sorter with small hard parts and four parts bins of rods/jets/gaskets/small parts), and can get a good fuel system running, then I think a typical TBI EFI conversion is worthwhile.


Be careful on going too big on the HP rating. High rating means higher flowing injectors. These units have a minimum duty cycle on the injectors, plus a minimum fuel pressure.
Which means, at minimum, the higher HP units HAVE to dump more fuel than the smaller units.
At idle this can be very bad. We're fighting this on a SBC with the MSD unit now, where it just pours gas down the intake, but the injectors are at minimum duty cycle. Tying to compensate so the engine doesn't puke means a really high, unstable idle. It's a very mild crate engine that has a rough idle at 900RPM in gear!!!


IMO, all the units <$1,500 are more or less a wash. Getting one with some manner of ignition control is good, but then you need to get that properly installed (more cost, more time).

cdrod

Eric:
It's an unmolested core carb, unproven but a good place to start.

Oddball:
I'll have to check the 2 cores I have to see if there are differences between the early and later model throttle shafts, but you might be right about about this.

I'm kind of at a crossroads here. I'll be finishing up the engine build and want to do a test run, so the induction system needs to be decided. I was already planning to replace the rusty old gas tank with a Tanks Inc unit with an in-tank pump because I'm running the ProComp heads on a small block and the mechanical fuel pump no longer fits. It's funny how these major builds evolve and change from your original plans. When I started this project, I never thought I would build a stroker engine or run aluminum heads, or even consider EFI. I was planning a stock rebuild, with a Q-Jet.

olds 307 and 403

That is why I went with it over the 750 Street Demon, with extra bracket for the 2004R it was a good $100 more. With no core and plating, Everyday Performance is also around the $400 mark.

cutlassefi

What's the duty cycle on the injectors now?
The Holley Terminator and FAST 2.0 have total spark control. And the only difference in setting those up is locking your distributor and an additional ignition harness. Not really a big deal.

SkylinesSuck

Is the Holley Sniper available yet? I'm looking for a fairly basic TBI style unit instead of rebuilding my quadrajet (again) just for reliable starts and inability on my part to properly tune a carb. Do any/all of these TBI units allow the user of the stock air cleaner to hide everything?

ELY442

http://www.jegs.com/webapp/wcs/store...=holley+sniper

oddball

5%

SkylinesSuck

That says it ships in June and the holley site says released in June.

ELY442

Bummer. At least you have 1 month to fine tune your carb (again).