Jump to content


Registered User
  • Content Count

  • Joined

  • Last visited

  • Days Won


TriumphV8 last won the day on January 3

TriumphV8 had the most liked content!

Community Reputation

17 Good

Profile Information

  • Cars Owned:
    Triumph TR6 red 2.7 EFI with VW pistons and Megasquirt
    Triumph TR6 blue 5.0 EFI with Rover engine and Megasquirt

Recent Profile Visitors

624 profile views
  1. No need to worry every modern car has a similar system. Normal procedure is once tuned you forget that there is a special system for fuel metering fitted and simply drive the car..... Although EFI tuning is much easier than tuning carbs or the PI you should be aware that some basic knowledge is important if you want to improve a system and not spoil it!
  2. Made similar investigations. on the highway all is in limits. And the cold air intake itself and maybe the air filter robs some power. With a crossflow head and air horns and some clean area from front to air horns the race engines gave best results. But at low speed and at traffic lights my V8 reported high MAT temps. I changed the place of the sender several times but still found the results did not make sense. Anyway the MAT easily reached 60 degrees and often 80 could be found. My EFI can correct a mismatch between measured MAT and calculated fuel. Especially in traffic jam, at hot start or slow driving this correction is quite busy showing me that the perfect place for MAT measuring is yet not found. In our case it shows that under bonnet temperature has quite a large influence on the mixture quality.
  3. The SU senses the pressure difference between outside (top of diaphragm or piston) and pressure loss in the venturi built by the piston at underside of piston where air blows by into the engine. So more or less it senses the air speed and lifts the piston to keep it nearly constant. The needle gives at that position the correct amount of fuel by its varying diametre. From that some correction is done but the air that is sucked in is different, too. As air changes density with low pressure air flowing through at underside of piston it now has less oxygen per litre and so carb "sees" another air media than he was set before. Mixture becomes richer like air is warmer what has same effect.
  4. There are three problems the non EFI community is dealing with: 1.) As told warm air is less dense and transports less oxygen into the engine. This results in less feed. 2.) Carb and PI does not sense that and from that mixture is not correct. 3,) Due to weather and height the air pressure is different what PI and carb do not sense, too. This is why racers had been set to perfect performance at the race track in the early days. Besides the warm air that is sniffed in from the engine compartment or in summer from the outside, too there is also the problem that the manifolds itself are heated from the exhaust and from the connection to cylinder head. They give the heat to the mixture passing inside and increase the problems. When making a dyno there is also a correction to be done where outside temperature and air pressure is needed for correction. This can be quite a lot in the range of +/- 5%
  5. If EFI is on alpha/n proper TPS and TPS setting is essential. If you are on speed density the TPS also is needed but not that much. As you now can go pretty close to lean mixture limit the TBs must feed alls cylinders equal and injectors must spray same amount. The connection (or two connections at CR) between the inlet runners help but in some throttle positions proper sync is needed.
  6. TriumphV8

    ECU help

    Without a log it is difficult to judge from the distance. You will need a wideband oxygen measurement to see what is wrong. If engine idles perfect I would try 1500rpm when car standing still and watch afr. Beginning with a fuel table that needs a tweak it can be accel fuel unwanted clogging in and VR sensor sending wrong data. Also some problem with ignition should be checked if this is also done by ECU. Pop in an old distributor and set it to be sure that this is not causing the problem. Best is to establish a logging possibility. I am sure the ECU can do so.
  7. The seats especially on the outlet get little dimples. Also the seats become wider. At minimum there should be regrind and a refacing to the correct width. Most of the outlet dimples should be gone. Inlet should show a clean grey seat. Also the valves and inlet runners and outlet should be cleaned from coal. I personally would swap the valve guides to those with rubber caps and grind the inlet runners to match the chamber. Also some material can be cut to make a smooth canal both inlet and outlet. As this can go wrong I would give that to a specialist. It is power for free and does no harm, so I like that!. I do not use seat rings because I expect head crack between inlet and outlet. If seats are envisaged I would only fit outlet rings.
  8. TriumphV8


    Due to the reason that the cam is casted into a cooled form where the lobes are quickly cooled down often the base circle is not hard. Best way to proceed is to risk a mark on the downrunning side of the lobe 5mm after the top. It will hurt but all other things are tricky. Normally my grinder does a hardness test a short time before the finish grind that the mark is away when finished. But that is more the case when a stock cam is for regrind and they have to decide whether they have to give it a final nitriding process to make it reliable again because the grind might have hurt the hardened area. As the base circle is grind down anyway I know that there often is no hard area.
  9. Looks great, really professional work!
  10. TriumphV8

    Ecu help

    I expect the pressure regulator is at the fuel rail? In that case the serious answer can only be measure the pressure at the regulator output where it goes into the return line. If there is pressure than the return line is too small. As this is could be the case easily it might be a good idea not to measure at all and add a fuel line in 8mm to be on the safe side.
  11. Most EFIs provide a smoothing tool to tame the pressure signal electronically from the manifold. 123tune for example is so lazy that the signal from a single WEBER DCOE can be used. For EFI that is a bit too much because some hesitation in fuel management will occure. We have to smoothen the signal become just suitable, but not more, not to sacrifice the crispy response on pressing the pedal. From a point forward this will not be possible with a wild cam. That point is sooner reached with a single throttle body like todays cars have and for Triumph TR6 it is somewhere aroung the 280 degree cam. At present we have a 300 degree cam tamed to provide the EFI with a proper signal. It is taken from the original PI manifold that connects all the six runners. Former ECUs and Software releases did not provide that function. I connected all six runners with small tubes and let them feed a little box from where I provided a tube towards the EFI. Was a bit tricky but also worked quite well. In those times the rule was to use Manifold pressure and rpm for smooth cams and for wilder cams swap to throttle position and rpm, called Alpha/n. I think the open source of Megasquirt, what at that time was the ECU to choose, pushed the software into the right direction we have now. It is quite simple: Look at the difference of the TR6 PI and Carb versions. They are more or less the same except the PI manifold. So from my view it is okay to give the 6 individual runners a power increase of about 10-15 HP. Talking about VE we must accept that the size of the runners is a little bit big, especially the throttle plates with 45mm would be good for 220HP. Also the runners are a bit short but there is not much space to extend without making a new inlet. We have to live with that but have the benefit of long stroke/short rods what will increase low end power.
  12. The pedal feeling is a mix of force and travel way. If you extend the lever the travel increases and the pedal feels like air in the brake. The same will happen if you reduce the diametre of the master cylinder or increase the diametre of the wheel cylinders. The booster is a good way to use big master for short travel and have force added to reduce the required force pressing the lever down.
  13. Hi Mimosa, sooner or later the work and learning about EFI will give a proportional result. The Patton thing from my view is a very good solution for American market where air pollution rules or availiability might regulate the tuning and the manifold. The half way will give more than half the fun, no doubt, but you can see from others experience it is like a drug. Good idea is individual inlet runners and ignition control. You get some pretty horses and more fuel economy for free and that is an argument if you spend time and money on the project. I would not expect that a system out of the box, fitted without specific knowledge will satisfy over a loner period. It needs the individual tweak and as that becomes very easy and cheap compared with a Weber DCOE setup it would be stupid not to try to optimize. Unfortunately I had to set several PIs in the nearer past and despite they all had pretty new metering units none of them was at the perfect point to work. So will the EFI start whereever you buy it, what system you will use and what setting you might copy from others, there will be a lot of potential hidden. The difficulty is to build the hardware and understand all that details and get it work than later together with the Laptop and Wideband Oxygen sensor. The easy and sweet thing is to lean back and tweak it from the passenger seat to perfection.
  14. This one looks nice, it is from Volvo 940 https://www.ebay.de/itm/Volvo-940-945-Bremskraftverstaerker-Hauptbremszylinder-B230FK-3530354-9157699-/172043943226
  15. I will do my very best....... Unfortunately I forgot from what Volvo because I bought two used ones and although the breaker told me I forgot through the years. Take a look at Ebay and watch for the belt in the middle not too big and the typical clean front towards the master..... It is 9" double diaphragmn.
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.