Okay, yeah I didn’t read into it, but saw the clamps and now the gasket you are talking about. Yeah the plate looks to be stainless, I would just weld in the plate as well. I didn’t even consider they wanted you to just clamp it on

 

Yeah it’s a plate that is curved with a bung, I think it’s easier to just do a bung

 

Yeah, the way the instructions specify to install the plate is to drill a hole big enough for the O2 sensor tip and then install the O2 sensor on to the plate and then the plate gets mounted to the exhaust with a gasket and then gets clamped on. This works OK for a little while but the clamps get loose and/or the gasket starts to blow out and then the sniper starts chasing lean conditions that don't actually exists and makes large changes to the learn table and then the car starts to run super rich and eventually will barely run (especially at idle and transition).

It is a bigger pain but the only way to do this properly is to have an exhaust shop weld in a bung or use the actual plate and just fully weld it in (without the gasket). The nice thing about the plate is that it is stainless so it you can TIG it on and it works nicely that way.

On the same subject folks also need to realize that the exhaust can't have any leaks (even downstream of the sensor for at least a couple of feet) otherwise you will run into the same issue. I have helped folks with a couple of Sniper issues and every one has had exhaust leaks that caused major issues- once those were sorted out the learn tables started to work as intended and do a really good job of getting a driveable state of tune without a dyno.

One last thing is that once you have your car running well, you really need to turn the learn percentage down to 10% or so from the 50 or 100 percent they ship with. If you have your learn percentage set that high your car will mask major issues and/or make huge changes in response to say an exhaust leak or bad O2 sensor.

Also, I recommend everyone dowload and use the Holley Sniper PC software and only use the handheld for minor changes or monitoring after the first start.

 

Here is the Sniper kit you will receive. I wasn’t sure if it included an O2 sensor bung, but it does have one, with a plate.

 

Here is the Sniper kit you will receive. I wasn’t sure if it included an O2 sensor bung, but it does have one, with a plate.

JHMO but I have done several EFI installs and I highly recommend welding in the O2 bung as the plates don't seal well and the O2 sensor is one of the primary sources of frustration folks will have with the efi install if it is reading incorrectly due to leaks or the placement of the O2 sensor.

 

Thanks Keith on those comments on the kit! Forrest and I worked and refined that conversion kit over last summer to get it right. Looking forward to seeing how it performs on your hopped up 2.4L!
I may still try this on my hopped up 2.6L but ultimately might go the injector swap route just so I can maintain the higher air flow capability.

 

Sunmit Racing right now has a sale on the 1100 EFI for 96.09 off. That’s a heck of a deal if you are considering this setup

 

Yep.. as I said it will work. Just as a 38DGAS will work.. They are made for larger motors after all.

The limitation is the intake.. and that will bottle neck the top end power and throttle response. Probably only truly noticeable on a Dyno. Because it will still probably be better than the original setup. Love to see what it does on the dyno actually.

 

So after talking with Gil at Opel GT Source, we are both on the same page that even on a hopped up 2.4 this 1100 would be more than adequate. Even Gil mentions unless you are running the Autobahn at 136mph, it will be just fine if not perfectly sized for a 2.4. A little research showed one guy downsized the 2 barrel Sniper injectors to less than that of the 1 barrel to make it work better. So today I received the kit for the 1100 installation on an Opel all models. I will say I was very impressed with the quality and the materials used to make this happen. There is a factory air cleaner adapter, that is cast and then machined. I thought it was still the 3D printed parts. No it is all machined parts, the thermostat housing is new and now has a boss that is tapped for the CTS and they even include a drill bit so you don’t have to go hunting for tools. Very complete, although I’ll need to get an O2 sensor bung. I have a 2.4 in the shop that would be a good candidate for the conversion, so I’ll probably start with it.

 

I firmly believe that it will work.. but no different than a 38 or a 32/36 with a 2.4L it will limit total power and top end due to limited and restricted airflow.

The 2300 I think on a 2.4L would be fine as well but you will need to tune it on a dyno.

In most cases (i.e. not racing and those that drive the car on the trailer and off and go to cars and coffee..) either will work OK, given the tunable nature of the sniper.

If the dyno on my 2.5L with a slightly bigger OR-77 cam, taller rods, and similar pistons is any indication, header, and the GoinEFI manifold. One caveat is I did have a Low port head vs a High port so that could affect it some as well. I would say we are probably roughly the same compression.

That said I was 122 HP at rear wheels ( roughly 140 ) - So, I would still say 140-150 HP is probably high. Your probably closer to 115-125

As It comes down to air flow.. ( assuming your modified distributor and my ignition table are close to equal thats another issue ).

I know Bob will correct me, as engine dynamics airflow vs how airflow works in a HVAC system can be different.

That said physics is physics and being a HVAC engineer and having designed my own intake.. I can tell you at least the "base" numbers we have here can tell a tale.

So if you interpolate the data and note that the GoinEFI intake is the only one intake there that was identical between the runs. So it gives an anchor to the data, that and the bare open ports.

1.9L vs 2.4L on my intake there is a 10 CFM bump on the 2.4L head around the 025 to .030 range :

104-110 CFM at 0.35​

108-122 CFM at 0.45 lift​

​

Roughly a 4-10% increase​

High Port Head Bare vs the Low Port Head - There is a 0 CFM at valve opening to 20 CFM difference in the bare head on peak..

So in General terms..

High port heads flow up to 20% better to peak of the cam lobe ( All things being equal and no porting, etc.. )

Apply that to a Stock Down draft intake on a low port head ( we didn't have a downdraft for the high port ) and even the Holley modified one by Bob was at best 95-98 thats a 10-20% loss

Some comparison on the charts, do a little algebra.. and you will see

IN GENERAL:

High Port = 0 (0-0.25 valve opening ) to 20% improvement at peak vs Low Port Head​

​

Down draft = -10% to -30% loss of air flow vs EFI and Side Draft intakes.​

So on a Downdraft at best your flowing 10% lower than a EFI or Side Draft intake at 0-0.25 for airflow

So sticking to a downdraft intake with a Holley, it will still run, but will be a limiting factor on top end power and pulling off the line..

That said, with your mods, and a downdraft, and such you're probably looking at about 90-110HP rear wheels.. (115 to 125bhp)

Which is still 15-25% better than stock and as no one has to tell you it's VERY noticeable.

So budget, ease of install, and the final expectation and all come into play.

Enemy of the great is the perfect, enemy of the good is the great..

The GoinEFI intake was initially designed to fit... | Facebook

 

I’m considering putting this setup on a 2.4 with 38 Weber on it now. I am seeing a lot of doubt that it is big enough for anything over a mild 2.0. The unit states around 175hp and I can’t help to think that most people are highly exaggerating their HP numbers and don’t really know what they got. So best I’ve seen on a stock 2.4 is 123bhp. I have a bit bigger pistons that are higher compression, but the 1mm thick head gasket to drop it down, and an Isky Combo cam.. . So I don’t think we are talking anything more than 140-150HP. Though I’m seeing that most feel the 2300 Sniper is too much. Though one member cut down his 100 pound injectors to 48 pound, so basically would be the same poundage as the 1100, which is a single 100 injector.

 

I think, in the end, the best thing to do is to give your car to a dyno tuner. Get it running at a minimally acceptable level and if you want things to be more perfect, give it to a tuning place. Unfortunately, there's far too many guys who think it's more fun to figure it all out themselves. Those are the guys that post never ending threads about their latest tweak.

I was almost there with my SSD manifold/2 injector/twin throttle body experiment, but a weird quirk in the shape of the manifold or the squirting force of the injectors caused all the fuel to excessively favor #4 cylinder, causing it to chronically flood. But I could tell that the power I was seeking was there, but just out of reach. The solution is to have the manifold modded with 4 injectors at the ports, which is what I'm having done. But, just in case that fails for some reason, I'm also having a custom "normal" manifold made or maybe I'll use Charlie's if it tests out okay.

My plan is to first install a normal manifold, take everyone's advice and tweak it to run acceptably, then take it to a tuner and see if they can get more perfection out of it. That will happen on my yellow project car. Once it's running fine and dandy, then I'll consider removing the stock 2.4 Motronic FI and install the modded SSD manifold on my GTX car. I'll use the charts and settings from the yellow car's normal manifold set up to get it running. Since both engines are stock and identical, they should both run pretty much the same.

As far as sequential injection, well, I'll have the capability to do that, but it will be something that I will do at a much later date. First get both engines running with the simpler batch fire injection, then decide to turn into an engine weenie and try to sequential inject.

I really don't want to spend the remaining years of my life endlessly dicking around with Opel engines. I don't think it's fun or interesting in the slightest to play with engines. I'm into all the other mods you can do to cars.

And I also like to just start my car and go for a drive and not spend one second thinking about how my engine is running.

 

Charles, a quick tutorial on pull-up resistors and keep in mind I'm a EE: Practically all digital signal generators whether triggers, logic gates or otherwise generally require a pull-up resistor off the output transistor. Otherwise the signal will float (i.e. the term open collector). The Pertronix has three connections just like any other Hall effect sensor. The third wire is not a wire but the grounding plate when you mount the unit in the dizzy. So you still have plus, negative, and the signal wire. The pull-up resistor is internal and built into the output of the hall effect sensor and that circuit drives the internal IGBT which then drives the coil negative side. It is NOT an open collector circuit on the output of the Pertronix. Properly wired into the Sniper, it works fine as a digital trigger for the ECU RPM input with no additional circuitry at all.

But in all honesty, this thread is merely about the install of the Sniper 1100 on a stock engine. It is not intended to be a discussion about the pros and cons of your distributor versus any others. Suggest starting another thread on dizzy options for ECU applications.

 

Mike,

I see you are the foremost expert of things called Holley, in regards to GT's. Is there a particular model you feel is best for a 2.4?

 

The Sniper rpm input is the low voltage side. The Pertonix is a Hall Effect sensor, same as your setup that simply provides the rpm pulse to the ECU. No difference at all. The sniper provides a separate coil trigger signal that runs through a coil driver device (nothing but an IGBT transistor circuit, and sold separately of course). All coils no matter what ECU or otherwise require a higher current coil driving device. As a matter of fact, most modern coils are what are called "smart coils" whereas the IGBT driver circuit is built into the Coil on Plug (CoP) or Coils near Plug (CnP) arrangement.

Granted, modifying the Opel dizzy to lock out the advance takes a little work but it's not that hard to do. So if yours is turn key then it does save some time and effort for those not willing to modify their stock dizzy.

 

The sniper provides a separate coil trigger signal that runs through a coil driver device (nothing but an IGBT transistor circuit, and sold separately of course).

This I think this the electrical difference ( excuse my ignorance of that end of the EFI system.. ) but the coil driver device is part of my system out of the box. The distributor has a pull up resistor ( thus the 3 wires and not two wires a Pertronix has ) and uses a Bosch ICM to drive the coils.

Per the Microsquirt directions :

Pertronix on Opel Dizzy :

My Distributor

The ICM can change to which version you want and let tuner studio do its work

If someone wants to go with one of the more exotic systems this can work..

The way it is "As is".. there is a way for the computer to see #1 and all 4.

Anyway, not sure this will work for the 1100.. but its what does make mine a bit different compared to a locked-out Opel Dizzy and Pertronix and it will work with a Microsquirt or Speeduino.

 

Lot's of CFM to HP calculators on google if you search for them and the conversion varies obviously depending on the efficiency of your engine design. But the majority of calculators yield lower numbers than most people think. Here's one calculator that indicates a N/A engine developing 100 HP only requires roughly 70 cfm. A 300 hp v8 engine only requires about 150 cfm according to motortrend.com. I'm no expert so I'm only offering what I've found thus far.

 

Also, keep in mind that you could use a returnless Edelbrock fuel pump system, like I use, and not have to come up with a surge tank or run a return line to the tank, just a small vent line to the tank that doesn't require enlarging a tank vent outlet and you also don't get the "toilet running all the time" sound from the fuel constantly getting pumped back to the tank.

 

This would all be new to me but has my curiosity. Not necessarily my wallet for just show car driving though.

 

Gil and I both think the Sniper 1100 is suited ideally for the stock to mild CIH engine and offers yet another option for a simple EFI conversion. Expect to see these adapter kits from OPGTS in the near future.

Just curious how insanely expensive is this conversion going to be?

 

$900 for the unit not bad as it comes with the computer and a display. Then the install kit and modification of the intake. Not too bad overall.

My unit without ECU but the custom intake.. I am looking at complete WITHOUT ECU/Harness ( $300-$400 ish ) and the intake only with throttle body and fuel rail, etc.. $1200 or so

Add a custom distributor and you’re at $1600 give or take. That said my custom EFI distributor can work with the Holley too if you want to go with a EFI tunable ignition..

So two different systems for two different use cases.

This will be a little cheaper, but for stock 1.9L motors, and mild 2.0L motors. Think of it as a modern 32/36 replacement.. It will be more than adequate for that use case. As good as any other option. I think a big valve head would be a bit resistricted by the 1100. It would run fine on it, but probably be restricted and the extra effort of bigger valves wouldn't be optimized.

My setup will be a little more complex and expensive, but for performance motors 2.0L and up. It would be like going with a 38DGAS or side drafts, or swap out for Jetronic/Motronic. It should also be a little performance boost to even mild 1.9L/2.0L High compression motors with larger cams and valves.

 

Here's a video of the first drive with the Sniper 1100.

Weather is hit and miss here in Ohio. We don't drive our Opels when they dump a bunch of salt on the roads so we have to wait until some good rains to clean the roads off!

 

Here's a video of the first drive with the Sniper 1100.

I'd be curious to know what sort of AFRs you saw, straight out of the box, and then after their auto-tune/learn feature had a chance to work for a while. Maybe AFR at idle, constant moderate speed, and WOT, rough numbers before and after learning.

In the video, I think I saw mid 13's at idle, maybe mid 12's with some throttle, but it was hard to see.

Or some data logs if the setup supports logging.

 

Went hunting found this.

Porting intake

I was looking through the forums, and came across several mentions of porting the intake manifold in order to improve hp. I didn't find any mention of what the best method of doing this is. Is this something that can be done by an amatuer? (I'm fairly handy with tools, but no mech. genuis). I...

www.opelgt.com

You can just bolt a piece in the bottom of the plenum.

 

Great job.
The size is plenty. I have a bit of experience with fish carbs which your system reminds me of.
The main mod you now need (being a performance single barrel ) is to prevent refection from a flat bottom under the TB.

I remember Bob has a suitable mod with a 90deg divider at the base of the plenum that would do wonders.
Great job

 

great stuff! thank you so much for making the effort to post a video!

 

Thanks Charles. The obvious drawback to this versus what you are doing is limitation on ultimate power for bigger CIH engines, lack of multiport fuel tuning and no 4 channel spark control. The Sniper can control timing which I've played with on my 2300 setup but went back to stock Opel dizzy. Only one channel that controls the coil firing and you still need to use the dizzy to "distribute" the spark.

 

The Sniper can control timing which I've played with on my 2300 setup but went back to stock Opel dizzy.

Curious why you went back to the stock distributor? I've got a Sniper 1100 to install on an air cooled VW beetle engine. I have a Bosch 009 distributor for it which I can lock out and use a Pertronix I module according to your wiring diagram for your 2300 experiment. Did this not work out nicely for you?

 

Here's a Youtube link for the initial start and engine run on this setup.

 

Here's a Youtube link for the initial start and engine run on this setup.

Sounds good.. !

 

That is pretty cool! What are you going to use for the air cleaner?

 

32mm throttle plate ? Sounds a bit small, the stock 19N etc Solex 35PDSI has a 35mm one.

 

You can't compare the bore of a carburetor to that of EFI. Carbs require a much larger bore to get the juices flowing. Fuel injection does not. However I will admit I'm surprised Holley advertises the capability of this unit at 175 Hp. Personally I agree it would be nice to see a larger bore, say at least 50-55 mm. According to calculators I've seen, 55mm is needed for 175 HP capability. That would be roughly 2 1/8" bore. Holley 1100 bore is 1.45".

 

Do you have a fuel return line back to the tank?

 

Great question! Yes, I forgot to mention that. We did run the return line back to the rear drivers side vent port. As previously mentioned in other EFI threads, those vent ports have a small orifice built into the tube so you need to drill it out to allow adequate flow for the return and avoid too much pressure buildup. Drilling that out can be tricky with tank in the car.

 

FWIW.. I like the idea too.. and was originally going to go that route with my manifold design.

But then one issue with the Holley 1100 crept up.. availability. ( Currently they do have an expected ship date of late April/May 2023 )

Also Steve H. the Red GT you see in my pictures. Had his fail on him and he sent it back for repair.. 3 months later he finally got it back and they hadnt fixed the main problem. He is still waiting..

I do love the concept and it would make things a lot easier, especially on mild motors. But QC and availability are what lead me down the other path.