Miata Turbo Forum - Boost cars, acquire cats. - Ti Vale Retainers. All Hype?

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- - Ti Vale Retainers. All Hype? (https://www.miataturbo.net/engine-performance-56/ti-vale-retainers-all-hype-47919/)

my engine builder told me ti valve retainers is kinda waste of money. Miata engine is not like Honda motors which won't get power after 6.5K ~ 7k RPM.

Stop typing, its a waste of words.

Heh, that's true too.

I'm still thinking, till your timing belt snaps, just go with bigger springs. :-)

Hmm, the numbers are in my other pants. And I still don't have the numbers for the stock springs. When I get them, I've got it all worked out - including which springs with how much extra/shaved weight are equivalent. Very easy to rank them, as soon as I find the OEM spring rates.

Ok, here's my spread sheet

Code:

What        Number        Mass (set)        Mass (each)

tappet+shim        16        761.6        47.6

retainer        16        177.8        11.11

clips        16        24.8        1.55

ex valves OEM        8        328.8        41.1

in valves OEM        8        343.2        42.9

ex Springs OEM        8        323.3        40.41

in springs OEM        8        347.9        43.49

+1 ex valve        8        340.5        42.56

+1 in valve        8        392.5        49.06

Ti retainer        16        59.27        3.7

Note I guessed on the Ti retainer

Code:

                % change        Stock Spring        St Sing        Eibach Sing        Eibach Doub        ST Doub

Stock In Tot        103.16        0        0        17.5        40        43.75        51.25

Stock Ex tot        101.36        0        0        25.33        49.33        53.33        61.33

+1 In Tot        109.33        5.97        -5.97        10.48        31.64        35.16        42.21

+1 Ex tot        102.83        1.44        -1.44        23.52        47.18        51.12        59.01

Ti Only In Tot        95.75        -7.18        7.18        25.94        50.05        54.07        62.11

Ti Only Ex Tot        93.95        -7.31        7.31        34.49        60.25        64.54        73.12

+1 Ti In tot        101.92        -1.21        1.21        18.92        41.69        45.49        53.08

+1 Ti Ex Tot        95.42        -5.87        5.87        32.69        58.09        62.33        70.8

Spring Rate (in)                        8        9.4        11.2        11.5        12.1

Spring Rate (ex)                        7.5        9.4        11.2        11.5        12.1

Seat Force                        41        56        66        75        74

Note here I guessed on the stock spring rates. I have no idea what they are. I might have swapped the seat force on the two dual spring set ups, but as it is, they are virtually identical. The stock spring seat force (for a pre-vvt) is from memory, I'll fix this later, but I think it's right.

I'm not sure what to do with some of these, they claim a "seat force" but it's taken at a different number, I don't know if that implies different retainers? For instance, the Eibach doubles are at a length of ~34mm verses the stock 38.5mm. Which, if you do the math, leaves a seat force at the stock length of only ~25 lbs, half of stock and perhaps not enough to work.

Anyway, this gives you a flavor of what I'm discovering, when I update it with spring rates from different years, we should actually understand what's going on and know what we're getting into when we upgrade springs.

Two things to notice:

1) The VVT springs are NOT identical. Pre-VVT, they are speced exactly the same, but in my VVT head the intakes are painted yellow, are physically longer (free length) and more beefy and weigh more. So I'm not sure I will see the gains I would on a '99 head with aftermarket springs, but I'll still get something. I wonder when FM says "9,000 RPM" if it's for the 99 cams, the vvt cams, or the MSM cams.

2) "% change" is the difference in weight, so bigger valves are 2 or 6% heavier, but the "springs" columns are the difference in weight divided by the change in spring to give you an instantaneous acceleration. In actuality, this is a bit of a simplification, since your movement in a given time is quadratic with time, AND it's not taking into account the difference in seat force from set to set, which is a problem for me as mentioned above. But I believe you're ok looking at this number as a guide to tell you what the acceleration will be at any point, so for instance eibach single springs with +1 valves are 31% faster than stock compared to supertech single springs and lightweight retainers which are 34% faster than stock, or overall about the same (the net effects cancel, but one way you get bigger valves).

So the plot thickens, quite a bit. I got numbers back from my machinist, and went to the SuperTech website to see what they have for solid info.

The first thing I noticed is they have two sets of dual springs, a 63lb seat pressure, 9.6 lb/mm set, and a 74 lbs seat pressure, 12.1 lbs/mm set up. Both of these in addition to the 56 lb/9.4 single which FM and others sell.

It's interesting they have that dual spring set up which is so low.

The other thing I noticed, if you do the math on their spring rates, they come out low. In fact, the high spring rate dual calculates out to be 9.8 lbs/mm while they claim 12.1. The only way this makes sense to me is with a highly progressive spring.

Which means the high spring rate springs are really only pushing that hard up at the top of the lobe (hence the wiping), but it also means it's a bit misleading to calculate everything on "k=(f2-f1)/(x2-x1)". I still think it's constructive, though.

The big news is I got the factory springs measured.

Spring Rate (in) 7.58
Spring Rate (ex) 6.83
Seat Force lbs 42
Seat Dist mm 39
Open Force IN 133
Open Dist IN 27
Open Force EX 124
Open Dist EX 27

Note that represents 12mm of max lift, quite a bit more than stock, actually, more than all but the most aggressive, race only cams.

So the SuperTechs are already 35% higher than stock (though it's interesting to note that mazda used 11% stiffer springs on their aggressive intake cam.

What worries me a bit, personally in my own situation, is that these eibachs I got will be too stiff. If they are not progressive, I suppose I am ok (who needs the extra force on the tip, when the valve is moving slowly anyway? It would seem you would want high seat pressure and really no increase when you are on the tip of the love??), because it means they are not too high. If they have the same sort of "progressive factor" which ST uses, then the "effective" spring rate is 14.2 lb/mm. Which I really doubt, but if it is, SHEESH!

Perhaps I'm onto something - the Eibach claims 200 lbs at only 27 mm?? Again I run the risk of linearlizing a problem away, but... OEM lift is 9.4/8.9mm.

Code:

        Stock STSing        EibSing        EibDoub        STDoub



OEM Open Force IN                        113        144        171        183        188

OEM Open Force EX                        103        140        165        178        182

Stg2 Open Force IN                        118        150        178        191        195

Stg2 Open Force EX                        109        148        175        188        192

For completeness:

Code:

                % change        Stock Spring        St Sing        Eibach Sing        Eibach Doub        ST Doub

Stock In Tot        103.16        0        0.0        24        47        52        60

Stock Ex tot        101.36        0        0.0        38        63        69        77

+1 In Tot        109.33        5.97        -6.0        17        38        43        50

+1 Ex tot        102.83        1.44        -1.4        36        61        66        75

Ti Only In Tot        95.75        -7.18        7.2        33        58        63        71

Ti Only Ex Tot        93.95        -7.31        7.3        48        75        81        90

+1 Ti In tot        101.92        -1.21        1.2        25        49        54        61

+1 Ti Ex Tot        95.42        -5.87        5.9        46        73        79        87

Spring Rate (in)                        7.6        9.4        11.17        11.54        12.1

Spring Rate (ex)                        6.8        9.4        11.17        11.54        12.1

Seat Force lbs                        42        56        66        75        74

Seat Dist mm                        39        34.2        39        35.8        33.7

Open Force IN                        133        154        200        210        177

Open Dist IN meas                        27        23.7        27        24.1        23.2

Open Force EX                        124        154        200        210        177

Open Dist EX meas                        27        23.7        27        24.1        23.2

Max Lift                        ??        12        12        11.7        13

Coil Bind                        ??        20.7        24.2        22.1        20.7

Basically, with my bigger valves, the Eibach singles will put me about where the Ti SuperTech single will. I.E. Intake is 38% improves and the Ex is about 61% improved. SuperTech looks like 33/48. I guess if I had it my way, I would want a 10% lighter spring for the exhaust, to move accurately match the OEM set up. When I get motivated, I'll look at the peak force (i.e. at full open for both cams), perhaps I'll learn the exhaust springs aren't as bad as I thought since they don't open as far, but the percentage change over stock will be about the same.

Anyway. Hope this helps someone. Or gets someone who knows more to join in.