8 replies to this topic

[lctriples]

Hey guys, just wondering if anyone has installed a Holley Sniper or similar modern EFI carby to an old school holden 6, and if so, was is hard to install. I realise you need to fit an 02 sensor which comes with kit, but can you use existing manifold (running a 2BL holley at the moment), existing electonic dizzy, and do you need to run an electronic fuel pump? Lastly is the performance and fuel economy gained worth the $2K investment. Apologies if this topic has already been covered, Paul

[axistr]

You need to run an electric fuel pump. The injectors need around 35-45 PSI. The Holley system should come will a pressure regulator. The electric pump will also prime the system to the regulator set pressure before starting. I'm not sure if your electronic distributor will run timing control, it will require a pickup sensor. The Holley Sniper system will have a box to tick in the ECM programing screen in the initial setup settings. I would control the timing with the Holley ECM if possible, there are plenty of benefits in controlling timing and getting the perfect timing curve from start up to rev limiter.

 

You would need to burn a lot less fuel with the EFI system to get back the 2k investment. However, yes you will definitely get better economy. It will also depend on how well your current system is tuned. Performance wise, you should pick up some performance, particularly in some areas where low vacuum, quick throttle openings, change in pressure and altitude hurts carby systems. If you have a perfect tune with the carby and ignition setup now then you may only notice minor performance increase. But it's extremely rare to find a perfectly tuned mechanical system and they will change and go out of tune over relatively short period. 

 

Going EFI is more about better fuel & timing control and you will notice easy start up hot or cold, won't fowl plugs, much better idle control, perfect air fuel ratio during all driving conditions, much better drivability even with performance cams. I have found the Holley systems very reliable, easy to fit and use, Holley self tune program is spot on and very easy to use. It's the best improvement I have ever made to my hatch and would never go back to a carby again. Even my lawn mower is fuel injected and wouldn't have it any other way.  

 

So many up sides to EFI. Just keep the fuel system clean and filtered, any wiring connections must be properly connected and you will have plenty of trouble free motoring.

[yel327]

Will detail my work so far in fitting one to my HK when I get some time this afternoon. To be honest the fuel system is the most work.

[yel327]

I actually discussed doing this in a thread in the last few weeks:

 

Back into Toranas after a long break - Introduction Forum - GMH-Torana

 

To answer your questions directly:

 

Holley does three suitable systems for the red 6. They have a 2BBL Holley replacement, plus the two different sized Rochester 2GC flanges. As I stated in that other thread, I'd simply use a 2600S/2850S or 186S intake with the small 2GC, this one:

Sniper EFI 2GC Small Bore - Holley

That is good for 350hp. Will give you the power and throttle response of an S engine and reliable cold starts etc that come with EFI.

 

As mentioned in that other thread, you are best using the Holley Hyperspark dizzy, coil and coil driver. But Holley don't make a red 6 distributor. Have a look at the other thread link in that thread about modifying a Chevy 6cyl distributor to suit a red 6 - you can buy a Chevy 6cyl Hyperspark dizzy. This will give you full spark and fuel control.

 

You require an EFI pump, and I'm pretty sure all of the 2 barrel options require a return line as they have an internal fuel pressure regulator set to 4bar (58.5psi). I'm using a Sniper Quadrajet as I wanted the distinctive Quadrajet sound and a spreadbore to boot, and these can be setup to run returnless like a VZ or VE with the fuel pressure regulated in the MRA. In any case the best way to do it is to get an original fuel tank modified with a weld in ring in the top so you can run an MRA from a Holden or Ford. I used the really tall MRA from a VT-VZ (VT-VX are high pressure with return line, VZ are regulated to 4bar at the MRA). Falcon are shorter again with VE the shortest, but I think the VE MRA are all regulated. Which one you use depends upon the height of your fuel tank where you get the weld ring placed. The MRA needs to push against the bottom of the tank. The MRA will have the connections at the top for the pump, a fuel sender, fuel out barb, a carbon canister vent barb and a return barb (used either for the return line from the Sniper or if running returnless, there is a return from the fuel filter located just in front of the tank (see the filter exit T in the attached image - one side goes to the engine, the other returns to the tank).

https://i198.photobu...VZ/P1040337.jpg

 

Have a read here about MRA's:

 

Fuel Tank Conversions To EFI | EFI Hardware

 

You can use the MRA's sender with a signal adapter to suit the car's dash gauge, but if you put it in your tank away from the original you can simply leave the original pickup in place and use its sender.

 

I'm using the whole Sniper and Hyperspark shebang on the 377 I've built for my HK. I'm also running air and steer and will use the Sniper to control the torque converter lockup in the TH350C. I want it to get nice cold starts, good choke, good throttle response etc but look original-like. I'm also over ULP going off in the carby, I'm sick of cleaning the tank and carb out in everything I own. At least using 98 with fuel stabilser I won't have to pull the carby apart and clean every 6 months. Note that after I got the HK's tank modified for use with an MRA I put a KBS kit through the tank, it now looks like glass inside.

[lctriples]

Thanks guys for the quick response. Quite a bit of information for me to digest so will have a good read over the next few days. Thank you again for input!

Edited by lctriples, 12 April 2023 - 07:19 PM.

[yel327]

If you go to the Holley website you can see all the installation instructions to read. They show you how to make a Sniper work with a HEI and an MSD too. Plus wiring, putting in an O2 sensor etc. The most work to do it right is the fuel. You can do it easier using an external fuel pump, surge tank etc but I reckon you are best off doing it with an MRA. Plus when you clean your tank out you won’t believe the crap that is in there.

Edited by yel327, 12 April 2023 - 07:50 PM.

[lctriples]

thanks yel327, good advice and will look into it  tomorrow

[Grumpy72LJ]

Hi everyone.

Thank you for this post. Very helpful info as I plan to go down the same route with the. Sniper. I currently run a 186 with stromberg WW, mild cam, early yella terra 179 head, pacemaker extractors and other mods. The carb is great but aging and looking for a smooth runner with no choke. Anyway, thanks again.

[neglectedtorana]

Anyone have any experience with the Holley Terminator X Max?

I am using the OEM computer for the LS1 and if I want to change something like the cam I have to go back to the tuner which costs to do it right on the dyno. With the Holley system my understanding is you change some of the settings so it will re-learn and its done.

 

Lately I have been looking at the Holley system to replace the OEM computer and wondering if they learn and tune as well as a human can?

Many great reviews online and on Youtube and if the Holley ads are correct the system is awesome.