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· Opel Addict Since 73
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Discussion Starter · #1 ·
Hey Y'all - I'm planning to start a rebuild soon on one of my 75 engines. I'll be putting in oversized flat tops, a better cam, perhaps bigger valves and larger exhaust. I'm not looking for huge performance increases but I'm wondering if anyone has played with the stock intake plenum. Would it help to do some port matching? Is there anything else that can be done with the intake plenum to improve performance? What about injectors or the little phenolic retainer plates??? I've had discussions with some of the folks here regarding limitations of stock F/I versus output and the MAF limitations...but any further suggestions would be greatly appreciated. Last week some snotty-nosed ricer said I should inject nitrous oxide where the cold-start injector is. Do these kids really do that kind of stuff? Old farts like me are curious about such things!!!
 

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Injecting NOS into cold start valve

That would give you a performance increase. however be really careful. It could cause some problems if you increase the HP too much without some major tuning. At least that is my understanding about adding major HP increases. You might be able to add a very small amount, maybe even using a switch that only injects it when your throttle is wide open. Similar idea to the way a turbo works. This idea could also be made to work with any type of Opel. But don't take my word for it. I haven't done it.
 

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Bigger Runners

There is an outfit called "Extrudehone" or some such that forces an abrasive paste through manifolds to increse the runner size and polish them internally - may be worth some investigation.

With NOS remember that more fuel is required too as NOS adds Oxygen to allow more fuel to be burnt. Just NOS injected will cause a MAJOR lean condition and destroy the engine.

Yes, Ricers do far worse than that and can be learnt from by us old farts! 350HP Opel CIH street engines anyone?
 

· Opel Addict Since 73
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Discussion Starter · #4 ·
Modest Increase

I'm not really interested in a nitrous system...I was just curious after this teenager mentioned it. I'm more interested in whatever minor improvements and tweeking can be made to improve performance without compromising reliability and street manners. I think the flat tops and cam will be the best contribution. I'm just interested in knowing if others have played with the stock F/I plenum.
 

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Increasing the airflow of the stock EFI manifold won't help you much, as your modifications to the rest of the engine have not yet maxed out the stock EFI intake manifold's airflow capacity. The stock EFI manifold can flow enough air for about 170-180 hp. The real issue of course if fueling control, which the stock EFI can't do too well if you deviate drastically from stock Opel specs.

I am using a stock 1.9 EFI manifold for my street-driven turbo Ascona wagon (about 280 hp by my calculations), but the intake manifold will be left dead-stock. It is getting a slightly larger TB with a proper TPS, larger injectors and higher flow fuel pump, and an aftermarket EFI computer. The standard L-Jetronic 'flap' style air flow meter is not up the task of metering the added airflow for my engine. HTH.
 
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· Opel Addict Since 73
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358 Posts
Discussion Starter · #6 ·
Turbo Ascona Wagon??

Hey Bob - Do you have photos posted anywhere of your Turbo Ascona wagon?? If not...would you consider posting one here? That's a car I'd love to hear more about. -Scott
 

· 70's Opeler, back 4 more!
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398 Posts
RallyBob,

What are you thinking about after-market EFI unit wise?

I currently have the L-Jetronic system too.

Are you using the standard injectors or did you go with another model that has a greater flow rate?

Thanks. I'm not looking to do anything currently, just interested for maybe down the road. It is getting harder to find the stock 2.0ltr Injectors and when I had mine professionaly cleaned, they didn't guarantee them, due to the age.

Chris
 

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I took my FI manifold to a local race shop. They welded plates over the old injector areas and installed injector bungs, built a custom fuel rail and fitted a 60mm throttle body. I'll have to get some pictures up, it looks really nice with the silver powder coating.

I'm running an EMS Stinger Fuel management system. EMS Website . It has fuel and timing maps dependant on load and rpm. Finally got the computer yesterday, they get shipped from Australia. The race shop that did my manifold is an EMS distributer.


Dan
 

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This is a work in progress. I have 'owned' the car for about two years, but it has never been in my driveway. It is in storage right now, but this spring it finally gets to come home. Nearly mint condition, original red paint, 1971 wagon with 60k +/- miles on it.

I have a European Ford Escort Cosworth turbo for it, WRX intercooler, 1.9 FI intake with 2.4 FI fuel rail and o-ring style injector mounts. I'm probably going with the S.D.S programmable system for the EFI, and I'm using a Ford Mustang 5.0 65mm throttle body.

Stock Opel injectors are just abou maxed out at 160hp. My injectors will be good for 320hp if I decide to go bigger with the turbo. Fuel pump is a 155 lph Ford 5.0 Mustang pump (in tank). Gotta love the inexpensive aftermarket 5.0 parts!
 

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Billet aluminum flywheel with S-10 clutch, Getrag 265, reinforced torque tube driveshaft, and Quaife limited slip with 3.89 ring and pinion. Will probably start off with a Getrag 240 until that self-destructs.

This will be just a driver, not for racing.
 

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Have any of you heard of megasquirt?
Iit is a sort of DIY fuel injection controller that you assemble but has lots of online support. I'm pretty ignorant about FI parameters but it seems to alow complete control of fuel and even ignition from a windows interface-you get to set your fuel maps and the whole thing looks like it only costs about $100. It's only a fantasy for me at the moment but there are a lot of people out there running this on a lot of different engines. I was just wondering if there are any opel people who have heard of this or are interested in it. You can check it out at
http://www.bgsoflex.com/megasquirt.html
 

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The megasquirt is the unit I was planning on running with my turbo cih project. They are actually coming out with a new unit, the ultramegasquirt, which has a lot of new features such as wide band 02 sensor, and simple spark control. The group buy for the new unit should happen possible in the spring, and I encorage anyone interested in a cheap EFI system to look into. The unit bascily does almost everything the really expensive units do, and the best part is, their is a large devolpment following with the unit and new features or varients are constantly being added.

The cost will be slightly more then $100 for the unit. After the relay board, stimulator, additonal parts, it runs nearly $200. All in all (pump, injectors, etc) my setup should cost me under $1000 with custom manifolds.


As a side note, a new spark module is being devolped by the same people. It touts ion sensing which is actually pretty slick. That unit wont be out till fall or possible later and will interface with the UMS. Again, do a little reading on this unit if you havent heard much about it, I feel it to be the best 'bank for the buck' for efi systems.
 

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I would love to hear more about your turbo cih design-are you making the manifolds yourself or having someone do it? what throttle body and sensors. which injectors? I hope to add FI and a turbo to my low compression 1.9 some day and any pics or info would help me greatly in my planning/day dreaming.
 

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Much of the project is still in the planning stages. Currently my block is being acid dipped and will be worked over similarly to bob's 1.9-2.4l article. Not exactly sure which rods im going to go with, but im leaning tword custom rods. After the engine is mostly together, im planning on using a gt 28 turbo (non ball bearing) or possible a t4 (depending on final displacment and cam choice). The intake manifolds and exhuast headers will be made up between a variety of people, I have access to a cnc plasma cutter at school and plan to cut out the flanges. The muffler shop will provide the runner piping and hopefully plenum, and my machinest has a cnc pipe bender that we will form the pieces into shape with. Final tig welding will also be done at his shop but I will be helping (helps drop the cost quite a bit). The throttle body is still unknow at this point as I dont know my exact displacment, same goes with the injectors. The sensors im using are the ones recommended by the MS site and yahoo list. I am also going to try and fit an intercooler (possible water to air), a ssqv (essentially a blow off valve), and water injection. The water injection shouldnt be too hard, but the intercooler and ssqv combined with the turbo and realtivly large intake manifold will make fitting everything 'interesting' to say the least. Obviously, I dont have an infinite budget, I'm trying to make my $$ strectch as far as possible with out cutting courners. This project is most likely going to take most of the summer, and I am taking lots of pictures :D
 

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Great info,
Keep us up to date as the project unfolds. That should be a killer motor when your done. I may follow in your footsteps someday and will be watching your build closely. What are your plans for the driveline? it seems like that could be an area that could get quite costly. Do you know what compression ratio and boost levels you want to get out of it yet? Good luck with it!
 

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Driveline is an opel 2.4l clutch which i already have (if i were doing over I'd get an s10 clutch but it was a good deal). Coupled to hopefully a getrag 265 with an undeicided rear end. Quife looks nice, but they might be out of my budget. I would like a limited slip, so I'm keep my options open. Compression will be at 8:1. I'm shooting for 20lbs+ of boost, but the efficeny of my intercooler and water cooling setup is bascily the limiting factor so until i get everything under the hood I'll have to wait to see how much I can run without getting into detonation, it also depends on turbo selection if you run too far out of the efficency range, the air gets pretty hot the engine would NOT be happy.
 

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Dan said:
I took my FI manifold to a local race shop. They welded plates over the old injector areas and installed injector bungs, built a custom fuel rail and fitted a 60mm throttle body. I'll have to get some pictures up, it looks really nice with the silver powder coating.

I'm running an EMS Stinger Fuel management system. EMS Website . It has fuel and timing maps dependant on load and rpm. Finally got the computer yesterday, they get shipped from Australia. The race shop that did my manifold is an EMS distributer.


Dan
Dan,

What's the latest with your project? Any pics?
 
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