Individual Throttle Bodied TVR 5.0L with Megasquirt
Discussion
Dax, that looks brilliant, reckon these bike inlet manifolds are the way to go on the RV8.
Just a thought, wouldnt the servo vac pipe work on whatever airbox you fit , or are you going for individual filtration?
And a question for most of the people who have replied, if you dont use an airflow meter( MAF? ), is this when you use a MAP sensor?
>> Edited by antonyj on Tuesday 18th April 18:03
Just a thought, wouldnt the servo vac pipe work on whatever airbox you fit , or are you going for individual filtration?
And a question for most of the people who have replied, if you dont use an airflow meter( MAF? ), is this when you use a MAP sensor?
>> Edited by antonyj on Tuesday 18th April 18:03
Hi all,
well I have now had it running and it sounds superb!! Anyhow, the pipes did collapse a little as GreenV8 said they might, but this was easilly fixed by putting the same ally tube I had made the manifolds from inside them to strengthen them. I had decided to connect the throttles with 2 seperate throttle cables attached to the throttle pedals, Im hoping this will be finished by the weekend.
The servo has to come from the engine side of the throttle plates to get some vacuum, as theres no vacuum in an airfilter, only air flow, I dont think that would create enough.
I am going to run mine in MAP mode, I have used this mode since installing the MS (MS has a built in map sensor) but I may have to switch over to TPS (alpha_n) when I put my foot down to keep the fuel efficiency as good as I can, I prefer map as its more accurate to load than TPS,
Phil
>> Edited by daxtojeiro on Tuesday 18th April 22:42
well I have now had it running and it sounds superb!! Anyhow, the pipes did collapse a little as GreenV8 said they might, but this was easilly fixed by putting the same ally tube I had made the manifolds from inside them to strengthen them. I had decided to connect the throttles with 2 seperate throttle cables attached to the throttle pedals, Im hoping this will be finished by the weekend.
The servo has to come from the engine side of the throttle plates to get some vacuum, as theres no vacuum in an airfilter, only air flow, I dont think that would create enough.
I am going to run mine in MAP mode, I have used this mode since installing the MS (MS has a built in map sensor) but I may have to switch over to TPS (alpha_n) when I put my foot down to keep the fuel efficiency as good as I can, I prefer map as its more accurate to load than TPS,
Phil
>> Edited by daxtojeiro on Tuesday 18th April 22:42
It looks great Phil, such a neat install and very low cost also?
You could probably sell kits!
I want to do the same thing over next winter to mine (Mega Squirt and bike throttle bodies). I've built a Megasquirt ECU before and was impressed with the kit.
What parts were difficult?
How did you sort out the throttle linkages?
How have you re-routed the cooling system, and thermostat?
Where have you placed the coolant temp for the ECU? Did you tap your new manifold to put an air temp sensor in or is there provision in the throttle bodies? What sensors did you use, GM?
Are the fuel pressure regulators built in to the rails?
Are bike injectors compatible with car ones (just wondering where you sourced you bigger ones from)? Are yours high impedance or low?
Sorry for all the questions, I'm just really interested in this one
More photos (or even a video when it’s all mapped) would be great.
You could probably sell kits!
I want to do the same thing over next winter to mine (Mega Squirt and bike throttle bodies). I've built a Megasquirt ECU before and was impressed with the kit.
What parts were difficult?
How did you sort out the throttle linkages?
How have you re-routed the cooling system, and thermostat?
Where have you placed the coolant temp for the ECU? Did you tap your new manifold to put an air temp sensor in or is there provision in the throttle bodies? What sensors did you use, GM?
Are the fuel pressure regulators built in to the rails?
Are bike injectors compatible with car ones (just wondering where you sourced you bigger ones from)? Are yours high impedance or low?
Sorry for all the questions, I'm just really interested in this one
More photos (or even a video when it’s all mapped) would be great.
Hi all
I'm also intending to do something similar aswell. My intention is to make a casting instead of fabricated item, something like in the attached pictures. (disclaimer - haven't got definitive measurements of the head inlet face and haven't yet finalised the best way of splitting the core)
Lower resin impression:
Upper resin impression:
The intention is to have:
75mm bore spacing (appears to be the most commonly available throttle body spacing).
42mm bore smoothly sweeping with 2-times-diameter bends down to a standard sized port.
Have enough material in for port-matching upto wildcat head port size.
The 'bar' at the top of the ports is to provide casting integrity and also when drilled through act as a vacuum rail for connecting brake servo, MAP sensor, Idle Bypass Valve connection, Fuel pressure regulator connection, etc.
Common casting but different machined coolant ports for left and right heads.
I could get a rapid prototype one-off for myself using investment casting. But I think there is a perhaps enough people out there who want this to get a batch made up using sand casting and get a job lot machined together. I could (perhaps) get stereo-lith impressions made and perhaps some patterns can be made using them. But I really have no idea how much this could cost. I've always been spoilt because I have designed some very complicated castings with moving cores and non-planar split-lines, however I just design the components and then give them to someone like Grainger & Worrall or JL French to actually sort out how the cores are made.
So any of you interested? Do any of you know people in the foundry business I could talk to? Obviously I want to do as much as humanly possible before handing it over to save on costs.
Cheers
Phil
PS. I'm very busy with my MSc at the moment and won't be able to really kick this off until mid-July.
I'm also intending to do something similar aswell. My intention is to make a casting instead of fabricated item, something like in the attached pictures. (disclaimer - haven't got definitive measurements of the head inlet face and haven't yet finalised the best way of splitting the core)
Lower resin impression:
Upper resin impression:
The intention is to have:
75mm bore spacing (appears to be the most commonly available throttle body spacing).
42mm bore smoothly sweeping with 2-times-diameter bends down to a standard sized port.
Have enough material in for port-matching upto wildcat head port size.
The 'bar' at the top of the ports is to provide casting integrity and also when drilled through act as a vacuum rail for connecting brake servo, MAP sensor, Idle Bypass Valve connection, Fuel pressure regulator connection, etc.
Common casting but different machined coolant ports for left and right heads.
I could get a rapid prototype one-off for myself using investment casting. But I think there is a perhaps enough people out there who want this to get a batch made up using sand casting and get a job lot machined together. I could (perhaps) get stereo-lith impressions made and perhaps some patterns can be made using them. But I really have no idea how much this could cost. I've always been spoilt because I have designed some very complicated castings with moving cores and non-planar split-lines, however I just design the components and then give them to someone like Grainger & Worrall or JL French to actually sort out how the cores are made.
So any of you interested? Do any of you know people in the foundry business I could talk to? Obviously I want to do as much as humanly possible before handing it over to save on costs.
Cheers
Phil
PS. I'm very busy with my MSc at the moment and won't be able to really kick this off until mid-July.
Cheers Jools, I will do when I have something a little more concrete.
Those John Eales ones look like they're for IDF flanges at about 90mm bore spacing. OK if you want a set of twin-draught webers or jenvey's ££££££££
The idea is to carry over as much kit from the bike throttle bodies as possible, especially the fuel rails, so arriving at a suitable bore spacing is critical. My very limited research (which I'm still unsure about) shows that 2004 CBR600 and GSXR600 has 75mm bore spacing.
Phil (daxtojeiro) could you confirm your bore centres for me, cheers.
Those John Eales ones look like they're for IDF flanges at about 90mm bore spacing. OK if you want a set of twin-draught webers or jenvey's ££££££££
The idea is to carry over as much kit from the bike throttle bodies as possible, especially the fuel rails, so arriving at a suitable bore spacing is critical. My very limited research (which I'm still unsure about) shows that 2004 CBR600 and GSXR600 has 75mm bore spacing.
Phil (daxtojeiro) could you confirm your bore centres for me, cheers.
daxtojeiro said:
Wheeljack,
my bore spacing is 80mm, 35 mm from one edge to the next and 45mm across the outside edge of the bore. Internal is 40 at the top down to 38 at the butterfly I think,
Phil
Thanks Phil.
80mm bore centres, I'm definitely going to have to do some more homework.
I hate to have to say this but Ive given up. I simply cant get it to run right, it coughs and pops whilst cruising, it splutters out of the intakes, it idles really rough and Ive balanced it all, etc, but it simply seems as if its idling on 6 cylinders, may be less. The only thing I can think of is the fuel is sitting on the small ledges where the rubber pipes join the alloy pipes. I could be wrong of course. I also have a very very small join between the 2 centre cylinders of each bank and Im wondering if one cylinder is stealing fuel from the other one, so if anyone is designing one of these setups then these are things to look out for. Im now at a point where I have to decide wether to carry on with this or to go for plan B (make a new plenum with a set of 2-4 throttles on the side or front), this would be a lot easier, I would then need to change the TVR trumpets (well they aint trumpets they are scrap metal pipes) for 45mm trumpets.
Phil
Phil
Sounds a lot like the symptoms I'm getting on the blower setup, which I suspect in my case are caused by fuel stand-off in the plenum being stolen by adjacent cylinders. Obviously the multi throttle system would eliminate that particular problem in yours, but perhaps you are suffering from the same AFR variation.
I can't make out a lot from the pictures but it does appear that there are various steps and joins in the intake tract, which might only need a small change in geometry to change the flow characteristics enough to cause flow separation. This could cause a significant variation in air flow between cylinder even though the geometry looks very similar at first glance. Is there any chance at all that you can smooth out the inside? Ideally, extend the pipework so that the parts butt against each other at the joins, or maybe taper the inner edge if you haven't already done that. Concentrate on the inside edge of the corners, this is where air flow problems are most like to start.
Would you consider putting a lambda probe on the primaries to see whether there is any consistent variation in AFR between cylinders?
I can't make out a lot from the pictures but it does appear that there are various steps and joins in the intake tract, which might only need a small change in geometry to change the flow characteristics enough to cause flow separation. This could cause a significant variation in air flow between cylinder even though the geometry looks very similar at first glance. Is there any chance at all that you can smooth out the inside? Ideally, extend the pipework so that the parts butt against each other at the joins, or maybe taper the inner edge if you haven't already done that. Concentrate on the inside edge of the corners, this is where air flow problems are most like to start.
Would you consider putting a lambda probe on the primaries to see whether there is any consistent variation in AFR between cylinders?
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