Heftiges Uno Turbo Video

    Zitat von Acki

    But at this Engines you can compare same setups with different charger.
    Rally Cam - I would think the same. Will start with 272 NA cam and look what happens, then I will simulate other cams the power isn't enough ;)
    Maybe 2876 works much netter with external Wastegate but I think biggest 2871 will spool faster and hold the power longer compared with same power 2876 because Compressor Wheel is too Big.


    But its an 2L engine, dont forget!(completly differnt from an OHC 1.4 8V)
    These 2876 and 3071 are almost street turbos for an 2L engine. (At Drag use mostly at least Gt35!!!!)
    Both turbo could reach almost the same HP, but its depend from the engine.


    "Maybe 2876 works much netter with external Wastegate but I think biggest 2871 will spool faster and hold the power longer compared with same power 2876 because Compressor Wheel is too Big."
    Sorry but it completly the opposit! whatever external, or internal wastegate!
    2876 could hold longer same HP, like the smaller 2871, which could be spool faster, but not enough to hold it so long. (it will spin so fast, than it will be out of good efficiency)


    About cam, i did the same, i tried a lot, and the result, power, wasnt enought to me. Finally i get the rally cams, thats was i needed.

    The displacement is different but on a turbo engine the only effect is the needed boost for the same power and the spooling of the turbo.
    When a Turbo can handle 400hp, it's no difference when you have 1.4 or 2.0l.
    Only the torque curve is different - of course. More displacement, more torque. Killer applications like a 1.9l 8V SOHC with GT25R or GT28R don't have more power, but much more torque.
    The valves have effect on the surge line (more circulation loss) and the boost you need for the power.


    In the opel scene the normal "street" use turbo is a GT3076R. Since some month the GTX3076R is the most used turbo.
    Sure, some guys install a GT28xxR, but most guys have 500-600hp (bolt-on Kits, I made intake and exhaust manifold for these kits).


    About the GT2876R, the bigger compressor wheel causes bigger lag. At higher revs you have the problem that the turbine wheel is too small compared to the compressor wheel (it's like a ratio). The exhaust pressure raises and the burned gas can't leave the cylinder.
    GT2871R didn't have these problems!
    An external wastegate can lower the high rev problem with the GT2876R but only compared with an internal GT2871R.
    The Flowmap shows only a difference of 5HP - that is the 3rd point against the GT2876R.
    When you are happy with the GT2876R, good. I wouldn't be happy. You can drive what you want.
    More I don't write about this turbo. :)

    I do it another ways, because you cant understand that a smaller turbo (2871) will spin much more to produce the same flow rate like 2876.
    And that more spin cause it cant hold it so long at high revs.


    I have 2871 48 trim, flowmap said its enough to 400HP.
    In 2010 was my car only 340HP@2bar. Why?
    Why is that if i set the turbo pressure higher till 2,3bar, car was weaker that at 2bar?


    Why is important the lag at Drag Racing?
    You talk to much about surge limit, but you never had it.


    I'm talking about my 1.4 8v Drag Car not an 2l Opel engine.
    It could be at Opel on 2l works better an 2871 like 2876, but i dont care, its an Uno turbo forum ;)

    2876R has 0.7 A/R on compressor side...
    Blade design etc. is the next point.


    Only rasing the boost is no guarantor for more power.
    With stock manifold impossible to hold the power very long.
    Velocity is too high, losses are too high.
    Backpressure in exhaust etc. there are serval points which can limit the power of your engine.


    I have a custom manifold for my uno, and I know that this design isn't the best - I know that I will have to create a new one.


    I had surge limit.. Of course it's an Uno forum, but in germany are no fast fiats. Only Opel/VW. And I worked for an Opel Tuner :D And I think what works great on a Opel engine can also be good for our engines ;) :D


    If you tried that 0.7 A/R than it would be more authentic.


    Yes, a lot of thing has effect on it, but you have to understand an 1.4 8v engine with almost 400PS is much different like an 2.0 16v Opel engine with ~500PS.
    If you want to compare it, do it like opel have to be at least 550-600HP or more because the 16v!
    In that case you also prefer an 2871 or an 3071?
    I dont think so!


    Mine is not a stock manifold, but i want to change it anyway.
    I also have an Audi S2 Coupe but who cares on an Uno forum? ;)

    Zitat von Acki

    Why Not? Falling torque is there also an issue ;)


    /edit: @cry: I collected your old posts to your actual account.


    Thanks, i already forgot those password, and i think email address is not existing anymore ;)

    The 2l Opel won't have more power with GT2871R or GT2876R.


    Engine size only judges about spooling (bosst vs rpm) and needed boost for same air mass in cylinders...
    Number of valves and camshafts only "adjust" this (ok it also can limit the output).


    When you have some nice mods on the S2 it would like to read about that here ;) (Offtopic area)

    Zitat von Acki

    The 2l Opel won't have more power with GT2871R or GT2876R.


    Engine size only judges about spooling (bosst vs rpm) and needed boost for same air mass in cylinders...
    Number of valves and camshafts only "adjust" this (ok it also can limit the output).


    When you have some nice mods on the S2 it would like to read about that here ;) (Offtopic area)


    But an 1.4 Uno turbo does! ;)


    S2 is stock, only the front is from RS2.