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About bm0p700f

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    Chief Member

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  • Interests
    MTB/road bikes, cars and watching telly.
  • Occupation
    Bike Mechanic/teacher


  • Garage
    BMW E34 530i (1988)

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  1. bm0p700f

    Exhaust options.

    I am.not trying to argue with anyone. I just can't join in with the slating.
  2. bm0p700f

    Exhaust options.

    I just tried recording the exhaust sound on a drive but the playback recorded no exhaust sound. It was there. Stupid phone. why are people so hung up on fritz power gain claims? Cannot folk put claims aside? For the record (as I have found so much conflicting information about alpina engines) I have determined the following for the alpina b11 3.5, b10 3.5/1 and b6 3.5 cars. I don't believe alpina polished the inlet ports. If they did it goes against what engine builders normally do. Polishing ports in general causes more fuel to fall out of suspension and power output falls. If alpina did polish the inlet ports it makes them an outlier as it not normally considered a useful modification. The older e28 alpina cars had cylinder head work that bmw copied for the b35 head. Think of the b35 head in the e32 and e34 as a mass produced version of the cylinder head aplina had made previously by hand from the b34 casting. Alpina not only used a revised camshaft with 280/282 degree duration and over 10mm of lift and a revised ecu, they also 1) used more fatigue resistant rockers, 2) altered the combustion chamber to a hemi shape with the 65cc volume adopted for the b35 head. These where polished as far as I can tell. 3) 144mm conrods to reduce piston cylinder bore friction 4) custom pistons with a 10:1 compression ratio with crown to match the new combustion chambers squish area. 5) The alpina cylinder head had 47mm/39mm diameter valves. 6) exhaust system although I have found no photos of it. 7) the inlet ports on the b34 heads where modified to look they do on the b35 heads. Obviously on an e32/e34 alpina did not have to do much at all. This cylinder head was developed for the e28 based cars. Bmw stuck with 47/38mm valves for the b35 head simply because there camshaft did not pull much extra air in past 6000 rpm. As for under the bonnet temperatures there are various factors at play here. The stainless manifold has a lower mass and heat capacity than the cast iron stock manifold. That will reduce the amount of heat stored. Also the stainless manifold is reflective so will emit less heat per mm^2 of surface area than the rough dark surface on the cast manifold. The stainless manifold has a greater surface area to emit heat. As a result there does not seem to much if any change in under bonnet temperatures. Just because fritz (and other exhaust manufacturers) make some bold claims does not mean the system is poor or badly designed. Also at some point your manifold has to come off to change the manifold gaskets.
  3. bm0p700f

    Exhaust options.

    Yes agreed and if I were to spend £2500 on the Supersprint manifolds for the m62tub44 engine that in my range I bet I would not see the claimed 15 to 20hp either. The m62tub46 engine develops 70hp more with a revised head and camshafts. The exhaust manifold is the same. The stock exhaust manifold is not the biggest restriction up to 6000 rpm. Therefore changing it does little or nothing for power. That's known. Any gains from the manifold come past that and engine has to be able to breathe in at those rpms we never use for it to breathe out freely. This is my second fritz system. I will most likey get another for a different car at some point.
  4. bm0p700f

    Exhaust options.

    Head warping is only an issue once a cylinder head is removed. Most people never know it has happened until the head gasket has gone. If one buy performance parts on stated claims then the buyer car has to be setup just like the test car. Fritz's claim maybe true for there test car on there rollers. That is also true for any performance part. No one should buy anything for claimed gains and see them as summative. It simply does not work like that. The weight difference in the manifold is quite a bit. My judgement is there's at least 15 to 20kg saved on the complete system. It's noticeable as you can lift the parts with ease.
  5. bm0p700f

    What fuel should we buy for the e28 now?

    Too much scaremongering here. If your care is not running well on e10 it is because there is a problem not with the fuel but with the engine or fuel system that needs addressing that the new fuel has shown up. E10 is not dangerous for bmw engines m10, m20 or m30, m40, m50, m60. Other manufacturers are affect due to the materials used in the engine and fueling system. Bmw seemed to have not cut corners and designed everything for longevity I.e water resistant. What is dangerous is people trying to strip ethical out of petrol (fire hazzard, spilage...) I am fueling my m30 with e10 and the car behaves very well. When I had an eta it made no difference of it was run on 95ron or 99ron fuels. I used to monitor fuel economy closely and could not spot a difference. If you leave e10 sitting in your tank for months then water ingress will do it thing over a period of years. So use it, you car is not meant to be for long petrol storage. If you spot a problem with the new fuel address the short coming in the car and don't blame the fuel. Old hoses need to be changed eventually. Fuel injectors need cleaning eventually..... Scaremongering nd worrying obscures the facts. It does not that help that car mags are full of the same misformed nonsense. They should no better.
  6. bm0p700f

    Removing Ethanol from e10

    Ethanol is more knock resistant. Bmw engines according to the government website of any age are o.k on e10. If problems do develop is simply because of petrol being left in tank for months at a time. So use your car regularly (that's why you have it) or use super unleaded. I shove e10 in my e34 which has an m30 engine. There are other cars which do use materials which are incompatible. It's not simply age of the car. Bmw must have seen ethanol coming.
  7. bm0p700f

    Exhaust options.

    fritz can claim what they like (rich said a m30b30 can do 200+hp) as these claims are just that claims to me which I would never verify. I have not had the car with this engine on a RR. A RR will be used with the new engine to make sure it set up right (afm spring tension). The difference in performance I noted could well be the blowing exhaust vs the new one. It could also be lower car mass. it is the sort of system that could provide a gain with more heavily modified engine ( lightly worked b35 head, high compression pistons and alpina camshaft,). one would not be able to separate the gain from the exhaust for the gains for the other changes as they all work together and not in a summative way. Also given the manifold is stainless steel it holds less heat than the cast manifold so it less likely to cause damage to my fresh engine. The system is also be lighter (stock system is something like 33kg excluding the manifold) and the fritz system is certainly lighter. With the cast iron manifold the whole thing is over 50kg. There is a performance gain there. So even if it does nothing for power the sound , weight reduction and potential reduction in risk of head warping is enough for me. Most of the gain you saw duncan could have been the camshaft. It's a bit hard to say now though. AFM delete should help a bit but if you have ready maxed out the air flow into the engine removing that restriction may not add more flow. What the biggest restriction is at 218hp is not the same as the biggest restriction at 233hp. It's all hard to say for certain but by itself a fritz system does do not much for power. Nor can one expect it to. With serious mods (alpina esque) it could do something and it has the other (in)tangible benefits noted. It should be added weight reduction is something I am going for. The op might want to the same. Lighter flywheel, lighter exhaust, a/c delete and lighter wheels. It all adds up on a heavy car. That weight reduction will help make the car quicker all by itself.
  8. bm0p700f

    Exhaust options.

    That probably true on stock tune or near stock tunes simply because one of the limit to power gain is the valve size on the b34 cylinder head. Schrick cams can't overcome that. One of the reasons you may not have seen the power gains you hoped for is the 46mm inlet valves. I don't recall the head work you had done included larger valves. Also alpina reworked the b34 cylinder head to look like the later b35 head (larger hemi chambers and revised inlet port and larger valves) the larger hemi chamber altered the amount of swirl in the inlet charge and altered the squish band for more complete combustion. Bmw did not go with the 1mm larger valves on the exhaust side for the mass production b35 head but kept the 1mm larger inlet valves. It's the inability of the b34 head to get extra air flow/ the limitations of the b34 combustion chamber to burn sufficient fuel that will.limit its power output. These are the only reason I can think of why alpina got more than you did. Hense the 6 branch exhaust on a m30b35 in stock tune will probabbly not help improve power much at all but on a tuned engine at high rpm it could. The stock b35 limit to airflow and power is the camshaft and the Lower compression ratio.
  9. bm0p700f

    Exhaust options.

    I think there is a small gain in power. I have not had it on a dyno though. However the old exhaust was blowing through the back box. It could be just that. It's quieter than a blowing exhaust. The note is typical bmw m30 but louder. Its not overly load in the car and there is no drone. I'd do a video but the idle note is quite different from what you here on the road and I cut video whilst driving. I fitted it because it will compliment the alpina engine copy I am having built for my e34 (260 hp hopefully). Alpina had a similar system on the b10. What you had in your e21 is a tuned m90. That made its way into the e28 alpina b9 in 1983? You may have had an earlier version. Of course if the cylinder bore was 92mm then you had an m30b34. The m90 had a 93.4mm bore. The m535i engine on the e12 was a m90. 93.4mm bore and 84mm crank giving 3453cc. These engines gave alot of low rpm torque. The m30b34 92mm bore and 86mm stroke did not arrive until the e28 debuted I believe.
  10. bm0p700f

    Exhaust options.

    The fritz system with manifold looks well made. I have had it one now for 5 months with no issues. That e21 is exactly what I would like to create. It must have been tail happy fun.
  11. bm0p700f

    Headliner fabric source?

    Well if you have a good headlining for a non sun roof e34 let me know. How does one remove the headling? I am willing to give this a go. The a b and Carbon Pillar trims have to come off but do the a and c Pillar trims simply pop off with careful prying. I have never done this before.
  12. bm0p700f

    Headliner fabric source?

    That's great. As it means the car does not have to inside while it being done.
  13. bm0p700f

    Headliner fabric source?

    I still have to replace the window trim. If it comes out through the rear door all the better.
  14. bm0p700f

    Exhaust options.

    I think he wants a note. The one good reason I can give you for not buying the fritz system is having to change the exhaust manifolds. One mine a stud broke, the in acceptable one and the engine had to come out to drill it out. However it has 12 new studs and nuts now so that all parts of the programme of renewal I am willing to undertake. If those studs have never been off then one if likely to break. If you fancy getting the engine for a good clean then why not. If you intend to keep her slowly over time everything needs to come apart and back together again. Is it a manual?
  15. bm0p700f

    Exhaust options.

    The one I went for is a fritz system. That a complete system including exhaust manifold. It's very nicely made but is a grand in total plus vat. I think its worth it. Its not that loud in the car but it had a note (a good one). Standing at the back of the car it is loud. I don't have experience of other systems. This is the second fritz system I have had.