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Opel Tinkerer and Rescuer
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Anyone try the new Redline Fuel Injection Throttle Body kits? I don't see one that is a bolt on for the down draft unless the DCNF bodies are the same bolt pattern as teh 32/36 in that case that should be the one we use.

The reason I mention it.. is they DO have a DCOE throttle body to hold the injectors in..

Also it looks as if the Redline kits are using the old L-Jet type injector bodies.. Which means technmically you could use the Redline kit with a 75' manifold. So you would have a easily tunable FI system...

Not sure just thinking out loud.

Charles
 

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Split this post to its own thread, in the proper Forum.

Goin, don't make me get out the voodoo doll... :D
 

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OPEL-LESS!!!
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can i have 1 too keith? :D
 

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GoinManta said:
Also it looks as if the Redline kits are using the old L-Jet type injector bodies.. Which means technmically you could use the Redline kit with a 75' manifold. So you would have a easily tunable FI system...
Well, you could use the Redline DCOE throttle bodies with sidedraft manifolds, and buy the Redline ECU, fuel rail, regulator, injectors, pump, etc. But you couldn't use any of the stock Opel L-Jet system with it, modern o-ring style injectors aren't the same size as the old hose-barb style injectors. Add up all the parts costs and you're probably in it for $3-$3.5K.

You could also use the ECU with the stock L-Jet intake manifold, assuming the ECU can work with the stock low impedence injectors, but you'll need to graft a TPS onto the standard throttle body. This was the route many people had discussed but by using the Megasquirt instead of a higher priced ECU such as the Redline. I suspect it's at least $1k just for the ECU, there aren't many available below that price....Megasquirt and Simple Digital Systems stand out as the only two I can think of that are cheaper.

Bob
 

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TBI . . . as only carb replacement.

GoinManta said:
Anyone try the new Redline Fuel Injection Throttle Body kits? I don't see one that is a bolt on for the down draft unless the DCNF bodies are the same bolt pattern as the 32/36 in that case that should be the one we use.

The reason I mention it.. is they DO have a DCOE throttle body to hold the injectors in..

Also it looks as if the Redline kits are using the old L-Jet type injector bodies.. Which means technmically you could use the Redline kit with a 75' manifold. So you would have a easily tunable FI system...

Not sure just thinking out loud.

Charles
First, DCNFs do not share mounting bolt footprint with our 32/36DGxV, 38DGxS and 40DFxV carbs (92mm x 45mm). . . they are slightly shorter and wider (85mm x 52mm). They use a single throttle shaft mounted with ball bearings just like a DCOE and unlike the geared twin shafts of the 38DG and 40DF mentioned before.

Personally, I've never been much of a fan of using throttle body FI, especially if just used as carb replacement on an otherwise carb intake manifold. You can control fuel mixture somewhat more precisely with it, but still retain all the negatives associated with channeling a wet mixture through the bends of the manifold . . . kind of defeats the prime benefits of FI, moving only air in the manifold and precisely adding fuel to it at the valve. :( OK, hopping off my FI soapbox! ;)
 

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Opeler
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There are now SO MANY brands of DCOE throttle bodies out on the market. Using a dual side draft set-up, is there an ideal throttle body length? I've seen them as short as 30mm, but not sure what the 'ideal' size/length would be for an Opel engine. I'm thinking of going this route on my 2.2, but not sure what would be the best, both from a fit and performance stand point. I know there are multiple manifolds, injectors and fuel injection ECU's that could be paired with throttle bodies...but I'd like to base the rest on the best performing throttle body size that would make sense on our Opels.

Any help and advice would be appreciated...

Eric
 

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Using a dual side draft set-up, is there an ideal throttle body length? I've seen them as short as 30mm, but not sure what the 'ideal' size/length would be for an Opel engine.
If you know your cylinder head's airflow (theoretical power potential) and the cam profile (actual power and rpm potential) then you can determine the proper intake tract length and header tube length that compliments those figures.

Just remember large diameter/ short runners are for high rpm power and smaller diameter runners that are longer favor lower rpm power and torque peaks.
 

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...but I'd like to base the rest on the best performing throttle body size that would make sense on our Opels.

Any help and advice would be appreciated...

Eric
... then you can determine the proper intake tract length and header tube length that compliments those figures.

Just remember large diameter/ short runners are for high rpm power and smaller diameter runners that are longer favor lower rpm power and torque peaks.
In my book 48's work well as far as TB size.
You could go larger but there will lag on tip in that you'll need to get around.

Just remember that the 48's can flow over 600cfm.
Size the package like Bob has noted. Aint tuning fun!
 

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Opeler
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If you know your cylinder head's airflow (theoretical power potential) and the cam profile (actual power and rpm potential) then you can determine the proper intake tract length and header tube length that compliments those figures.

Just remember large diameter/ short runners are for high rpm power and smaller diameter runners that are longer favor lower rpm power and torque peaks.
So, what would these figures be for stock motors and cams? 1.9-2.4?
Does anything change w transmission types? 4 or 5 speed vs automatic? I am obviously most concerned w my specific set-up, but this info would be good to know for all combos.

are the runner lengths and specific performance just for throttle bodies or in combo w the manifolds?

I'm still trying to get my brain wrapped around all this stuff...

thanks for all the expert help!
 

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are the runner lengths and specific performance just for throttle bodies or in combo w the manifolds?

I'm still trying to get my brain wrapped around all this stuff...
The basics of how this stuff works isn't too complicated really as I found out when I started dipping my feet in the waters. Most people should be able to improve on a stock induction setup by using common sense once they gather some basic info

As mentioned the rule of thumb is;
Short, large diameter runner = more HP high up in the rev range
Long, small(er) diameter runner = good torque low down and wider power band

The intake runner starts at the mouth of your carb, or in this particular case the TB, and most likely you'll be running trumpets on them in which case it would start at the tip of the trumpet, and it ends at the inlet valve

So for a conventional street engine you'll want the runners to be as long as possible and unless there's something I'm not aware of the length of the individual components doesn't really matter so if you get a great deal on some really short TB's you can just run longer intake manifolds or trumpets. Having said that, the length of the intake manifolds does matter because that's where the air/fuel mixture will need to change direction a bit since the spacing between the runners change from the TB's to the head and a longer intake means a smoother curve. Assuming this is going into a GT then I would get short TB's as that would allow you more freedom to choose longer and better quality inlet manifolds and then get the longest trumpets you can fit to make up the rest of the runner

Unless you're planning on running a close ratio transmission you'll want the widest power band you can get or you'll constantly be chasing the right gear as the ratios in the stock 4 speed transmission aren't chosen with spirited driving in mind and the 5 speed Getrag is no better in that respect really as the 5th gear is only an over drive gear and the spacing between the gears are pretty much the same. Having a 3 speed automatic would only make the choice even more obvious as you need an even wider power band

If you're building a 2.2 or a 2.4 then obviously those have more torque to begin with from the increased capacity as well as better torque characteristics due to their longer stroke which would allow you more freedom to chase HP higher up in the rev range but to me the choice is obvious, you spend 99% of the time utilizing the bottom end torque and I would spend my money improving the power in the rev range I use the most

All of the above is of course not always true, an experienced engine builder have all sorts of tricks they can use to pull of their "how the heck did you pull that off" stuff combining high end hp while maintaining a reasonably wide power band but that's way beyond my knowledge so this is how I've planned out my engine builds over the years

I'm currently in the process of putting together a TB setup for my own engine and chose to go with Jenvey's DCOE style TB's, this is my first experience of messing around with FI so I'm excited but also a bit overwhelmed about the amount of information and options available
 

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Opeler
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So for a conventional street engine you'll want the runners to be as long as possible and unless there's something I'm not aware of the length of the individual components doesn't really matter so if you get a great deal on some really short TB's you can just run longer intake manifolds or trumpets. Having said that, the length of the intake manifolds does matter because that's where the air/fuel mixture will need to change direction a bit since the spacing between the runners change from the TB's to the head and a longer intake means a smoother curve. Assuming this is going into a GT then I would get short TB's as that would allow you more freedom to choose longer and better quality inlet manifolds and then get the longest trumpets you can fit to make up the rest of the runner
Absolutely true, except the whole theory is compromised with GT's heater box in place which is Eric's case. Due to limited space, the shortest components are required, good or bad. :banghead:
 

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Opeler
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GGL-

thanks so much for the comprehensive explanation of the throttle body set up. you definitely helped clear up some of the questions around the runner length, specifically the throttleday body being in combination with a manafold for overall length.

I'm really torn between going to throttle body fuel injection route or dual 45 dcoe's. both are going to require extensive work, however they both have their own pros and cons:

throttle body fuel injection: running all new fuel lines including a return, the pumps, the wiring, possibly new ignition/distributor and of course the cost isn't really cheap. the power and tuneability however would be fantastic.
dual 45 dcoe's: getting the tuning dialed in can be difficult, what the cost is much less than what the other set up with the.

my wife asked me last night what I've been reading up on so much lately... and I asked her if she'd rather have a heater in the car or go faster. for response was a pretty simple one, "go fast, duh. we don't drive the car in the winter time anyway. And if we do I can just bundle up." so the issue of having enough space in the gt should really not be in issue.

I'm really not sure which way to go, but I know I want to go in one of these directions...

I know that there are people that are going to support both of these, and I'd love to hear practical experience to help make this decision...
 

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Just Some Dude in Jersey
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You might want to consider going the single side draft route. Then there's no need to nuke your heater box. Theoretically, whether you have two side drafts or one, the same volume of air will pass through the carb, only with a single carb it happens twice as often. Any inefficiency comes from the shared manifold. But, the currently available Midikit SSD manifold has a shared plenum which should help mitigate the problem.

I've never read any stats about the hp difference between identical engines with singles vs. duals. If we're talking just a 5hp or less difference between the two, you could save yourself a whole heap 'o' money and time.

Then, there's going the turbo route to consider. I'd think that there'd be way more hp potential going the turbo route than the mega-carb or ultra-injection route.

Since freak show hp seems to be all you care about, why even stay in the Opel engine world? You're going to blow up your rear axle and tranny in short order and in no time that baby's gonna be sittin' busted in your garage. You might as well do what I think was your plan originally and Americanize your whole drive train. Be patient and make the kind of car that you had originally planned to make.
 

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Opeler
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You might want to consider going the single side draft route. Then there's no need to nuke your heater box. Theoretically, whether you have two side drafts or one, the same volume of air will pass through the carb, only with a single carb it happens twice as often. Any inefficiency comes from the shared manifold. But, the currently available Midikit SSD manifold has a shared plenum which should help mitigate the problem.

I've never read any stats about the hp difference between identical engines with singles vs. duals. If we're talking just a 5hp or less difference between the two, you could save yourself a whole heap 'o' money and time.

Then, there's going the turbo route to consider. I'd think that there'd be way more hp potential going the turbo route than the mega-carb or ultra-injection route.

Since freak show hp seems to be all you care about, why even stay in the Opel engine world? You're going to blow up your rear axle and tranny in short order and in no time that baby's gonna be sittin' busted in your garage. You might as well do what I think was your plan originally and Americanize your whole drive train. Be patient and make the kind of car that you had originally planned to make.
" freak show hp" is not an accurate statement at all. That's not at all what I'm trying to achieve. I'm just trying to achieve the most performance and fun driving experience out of the 2.2 motor that I have. and having the 2.2 motor, a single side draft is out of the question. They never made a manifold for these motors. just as with every other decision that I have made for the car, I will continue to be thorough and thoughtful before making any decisions. I have a wonderful Opel GT amd I would just like to maximize the opel drive train as it is. And as far as what you think my plan is for my car, I'm doing exactly what I planned on doing... making it the best car I can, all while keeping Opel at its core. now that my intentions are all very clear, Id like to get back to what I'm trying to accomplish in thisthe thread. That's gathering more practical information to make an educated decision on going with dual carburetors or throttle body fuel injection...

as always, thanks for any at all anticipated help and advice

Eric
 

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IMO the intake valve to throttle plate length should be eight -nine inches long.
Then use whatever length stacks that will fit.
 

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Opeler
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IMO the intake valve to throttle plate length should be eight -nine inches long.
Then use whatever length stacks that will fit.
thanks for that bit of info, I appreciate the input. I'm currently gathering info on several 2.2/2.4 specific intake manifolds to determine which will work best for the size, cost and behavior characteristic (more low end or high end performance)

I'm sorry. I didn't mean to rub you wrong! :no:

Myself, I've going SSD on a 2.4. :veryhappy
I appreciate you saying that. it wasn't intended to be harsh, but I wanted to be clear. I've read about and followed your gameplan for your car on several threads, however that is not a direction I wish to pursue. and as much as I genuinely do appreciate input, I just wanted to make sure this thread stays on a focus of throttle bodies or potentially dual carbs, and not turn in to a SSD platform. no hard feelings whatsoever my friend.

Eric
 

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Absolutely true, except the whole theory is compromised with GT's heater box in place which is Eric's case. Due to limited space, the shortest components are required, good or bad. :banghead:
In that case a TB setup is def easier to fit than a DSD setup, Jenvey's shortest DCOE style TB's are only 30 mm long (I assume other brands have short TB's too) which is 88 mm shorter than the Solex carbs in my Alfa (DSD setup) and I assume Weber DCOE's are of similar size I just didn't have one handy, would that fit in an unmodified GT engine bay with a set of short manifolds ?
 

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I'm really torn between going to throttle body fuel injection route or dual 45 dcoe's. both are going to require extensive work, however they both have their own pros and cons:

throttle body fuel injection: running all new fuel lines including a return, the pumps, the wiring, possibly new ignition/distributor and of course the cost isn't really cheap. the power and tuneability however would be fantastic.
dual 45 dcoe's: getting the tuning dialed in can be difficult, what the cost is much less than what the other set up with the.
I have no experience building a TB setup but as you I've done a lot of reading lately and I've looked into this for the past year and just decided it was time to just do it. One thing that will make the installation easier is using a fuel filter with a return loop, I believe I read about that in Juan's thread about the FI he's making, negating the need to run a return line all the way back to the tank and modifying that for a second fuel line .... Ill see if I can find it again

As for DSD setups, I understand it's quite difficult to fit in a GT without modifying your heater box but once installed you won't be dissatisfied. Tuning them to your engine is really simple, you bring your car to a shop equipped to re-jet them to fit your engine, which means a rolling road. :cool: The guy I used found an additional 4 hp at 6k rpm and some 10 hp at 3k rpm, my 45 DCOE's came out of an Opel Rally car and I thought it ran pretty well as it was. That was probably the cheapest HP of the whole engine build. Once they've been set up properly you will never need to touch them again, in fact I feel an urge to slap people who constantly keep fiddling with their DCOE's. For crying out loud they've got fixed jets and if left alone will never "go out of tune", the only thing you will need to do every now and then is adjust the "balance" between them depending on your linkage setup as they tend to move around a little bit relative to each other if you use the recommended flexible rubber mounts. Takes 30 secs once you get the hang of it

I absolutely *love* Weber DCOE's and I think it's the best thing since the bikini, the major reason I'm not going there this time is the urge to do something new and wanting to give "Dan's World" a try :yup:, with the tuning flexibility and all that comes with it, like having different setups for longer trips and track days
 
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