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Thanks, JR. We are separated by a common language. Throttle Body Injection here is commonly taken to be injectors up in the throttle body. So I'm sitting here wondering, what the hades is Blownie going on about. Cheers for the terminological extricatory disambigulation!!! I'm mixed up by your post. You extoll virtues of the ITB's and the downsides of a single TB, and yet it's your plan to install a single TB? How will a single TB allow you to get multiple injectors right next to the head anyway? I'm totally lost, unless my terms are upsidedown with yours or keyboard dyslexia has struck! Norm Norm, TB != TBI. What you're talking about is a Throttle Body Injector system, where there is an injector built into the throttle body, which often bolts onto a carb manifold. This is often known as single-point injection. What BlownImp is suggesting is a single throttle body (with no injector in it), with a plenum-type manifold and an injector in each runner - known as multipoint injection. This is used on most OEM injection systems now. I think the reason that he's going to a single throttle body is that most individual throttle bodies (motorcycle ones anyway) have the injectors in the body, so contribute to a larger wetted surface in the manifold, due to the distance between the injectors and the valve. |
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 Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com |
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gn3dr
Part of things
Posts: 391
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;D That S1600 engine only used a single t/b due to regs, if it didn't have to use single it would b on 4. I sort of did what you are thinking of with your IMP, with my 1.9 205 gti, yes it was originally injection, BUT, stone age clockwork Bosch Jetronic, flap type AFM, throttle switch and a Vacuum advance Dizzy. I sourced a Bosch Motronic MP3.1 ECU from a Citroen ZX 1.9i Volcane (essentially the same engine as the 205) which is a coilpack + MAP sensor, proper throttle pot. Vastly improved manners, improved MPG, nicer torque curve, also mappable  Afraid I can't help specifically with the IMP application though, but do get where you're coming from  Yep I was just going to say what you said. A single throttle body was implemented in S1600 when the Saxo on ITB's was winning everything. I drove a S1600 Puma on a few rallies and I can tell you that it was a pig to drive on road sections between stages - very highly strung & tempermental and that was even with a dual map type system for road and stage. Whereas the kit car Puma which had ITB's was supposed to have much better driveability (although I never got to try one of them). Injector location is also going to depend on the application - closer to the valve is better for emissions etc. but for a high revving motorsport application further away from the valve is better at high revs. On the Citroen Motronic ECU's - I've read before about how these are mappable - almost like an aftermarket ECU but I haven't been able to find much info on this. Is there software easily available to do this? Of course the other thing I haven't seen in the thread is another important thing ITB's give you ---- the sound |
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yes, the sound is another MAJOR factor in choosing ITB's As I don't know much about imp engines, what is it? and was it used in anything else that may have had an ecu? or is there a similar engine that you could borrow an ecu from? If there isn't it'll be a case of getting an ECU like a DTA S40, Emerald K3, OMEX 600 and so on, but the way to choose which brand to go for is to find your local reputable mapper and ask what their preferred system is. gn3dr, there aren't many out there that can do the Bosch mapping, the only person I know of that can is Wayne Schofield at Chipwizards in Lancashire, he is one of the very few people that can do the Magnetti Marelli ECU's too, I do believe he was involved in developing the process, with the MM I know that the original chip needs de-soldering, a socket fitting and a replacement chip fitting. He then does live mapping on the RR then finally burns the map to the new chip. The Lynx/Rotrex supercharger kits for the 306 gti6 engines use the original MM ecu with a suitable map done by Wayne. |
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yes, the sound is another MAJOR factor in choosing ITB's As I don't know much about imp engines, what is it? and was it used in anything else that may have had an ecu? or is there a similar engine that you could borrow an ecu from? If there isn't it'll be a case of getting an ECU like a DTA S40, Emerald K3, OMEX 600 and so on, but the way to choose which brand to go for is to find your local reputable mapper and ask what their preferred system is. . The Imp was a purely theoretical thing as that's what Frank knows. After he sold FAF though (silly curse word!) he is Impless... For the moment.  I'd be interested as to why Kai thinks using Carbs as TBs is a bodge though... |
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burns
Part of things
Posts: 373
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Is there a way around the issues with big cams and plenum based efi then? I've got a reasonably lumpy cam for my 5.7 sbc build and was going to go with after market tpi of some sort, but don't want to have to fight map sensor issues all the time.
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It's ok chaps, I understand that individual TB's would make for a better overall package, dependent on application and injector position, and it makes sense that the saxo S1600 car was doing well with them. However I was responding to MDH's post about a single TB not working well with big cams, this is not true as can be shown by the S1600 engines because of the regulations. Hey Blitz, bit of a mix up with the acronyms! Your right, it would be real tough to get the injectors next to the head with TBI WelshPug, would be pretty difficult to get an original ECU for the imp, it went out of production in 1976! A little bit before the first electronics were used on a car engine However, you are right, an ecu can be had and will work, as my imp shows  |
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Kai
Part of things
Posts: 276
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Apparently the injection system from a Volvo 240 with the B series engines can be nearly directly transplanted over, although i have no idea what work would be required to adapt it properly. There's an imp site out there that very vaguely describes it, but no expanded info...
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However I was responding to MDH's post about a single TB not working well with big cams, this is not true as can be shown by the S1600 engines because of the regulations. WelshPug, would be pretty difficult to get an original ECU for the imp, it went out of production in 1976! A little bit before the first electronics were used on a car engine However, you are right, an ecu can be had and will work, as my imp shows Sorry Blownimp, but your exhaust appears to be blowing! Big cams and a plenum result in a nasty drive train shunt as the vacuum signal get distorted. Ask any Elise owner with big cams. As for the SS1600 - Its a rally car not a road car so only has two throttle positions - shut or wide open! As for the BMW tb's, I'll measure them when I next have a chance. From memory they're 30 or 32 - not too far off the choke size in my old Carter 998. |
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Koos
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...1976! A little bit before the first electronics were used on a car engine Cheers, Blownie, but pendant mode on the electronic thing, I can't help it, as I am a major Pontiac head: "The first electronic ignition (a cold cathode type) was tested in 1948 by Delco-Remy,[2] while Lucas introduced a transistorized ignition in 1955, which was used on BRM and Coventry Climax Formula One engines in 1962.[2] The aftermarket began offering EI that year, with both the AutoLite Electric Transistor 201 and Tung-Sol EI-4 being available.[3] Pontiac became the first automaker to offer an optional EI, the breakerless magnetic pulse-triggered Delcotronic, on some 1963 models; it was also available on some Corvettes.[3] Ford fitted a Lucas system on the Lotus 25s entered at Indianapolis the next year, ran a fleet test in 1964, and began offering optional EI on some models in 1965.[4] Beginning in 1958, Earl W. Meyer at Chrysler worked on EI, continuing until 1961 and resulting in use of EI on the company's NASCAR hemis in 1963 and 1964." (Wiki) |
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Team Blitz Ford Capri parts worldwide: Restoration, Road, or Race. Used, Repro, and NOS, ranging from scabby to perfect. Itching your Capri jones since 1979! Buy, sell, trade. www.teamblitz.com blitz@teamblitz.com |
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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I'm pretty sure blownimp was talking about electronic control/computerisation rather than electronics in general.
I would have thought the easy way around big cams with a single throttle body would be to run the TPS as the main load sensor rather than MAP.
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I'd be interested as to why Kai thinks using Carbs as TBs is a bodge though... I was looking into this a while ago too, and I think it's basically because you don't need or want the restriction of having a venturi in the inlet, not to mention all the other now redundant gubbins in a typical carb. You might have a problem with icing too, though this should been solved satisfactorily by the oem. A feasible route to single point injection on an old motor would to be to salvage the TB/injector/pump/airbox/filter/sensors/ecu from a mid 90's Vauxhall roughly the same power as your intended application and mate it to the existing manifold with an adapter plate. One day I will actually try this... |
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I'm mixed up by your post. You extoll virtues of the ITB's and the downsides of a single TB, and yet it's your plan to install a single TB? How will a single TB allow you to get multiple injectors right next to the head anyway? I'm totally lost, unless my terms are upsidedown with yours or keyboard dyslexia has struck! Norm
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