Gearbox Blast Plates

[chulozumo]

Anyone ever used blast plates on their 5 speed? Anyone in NZ make them? I like the theory behind it, but unsure if it's actually worth it

http://mooreperformanceparts.com/products/blastplates/

[Ninja8)]

Interesting! Subcribed

[GC8E2DD]

When they say dyno tested up to 750hp, I can't help thinking that doesn't really prove very much. Unless they were doing peak torque clutch dumps or something.

[loner]

It looks like they will foul on the down pipe.

[Andy_Mac]

http://legacygt.com/forums/showpost.php?p=5121736&postcount=29

Truck loads of space with whatever downpipe is on that car

[pedro]

Shouldn't they be anti-blast plates ?

[loner]

 Andy_Mac said:

http://legacygt.com/forums/showpost.php?p=5121736&postcount=29

Truck loads of space with whatever downpipe is on that car

Sure, but the two bolt holes on the gearbox between the brace and the axle output are where the down pipe

should be bolted.

[boon]

From the name I thought this was going to be some sort of scatter shield to protect your feet if the clutch grenades.

Personally I don't really see how a bit of case reinforcement is going to stop either the shafts or the gears from falling to bits but I'm not a gearbox engineer either.

[ADIKT]

Hmmmmm

[loner]

synchromesh gears push outwards flexing the box causing failure... or some sh1t.

[Guest]

Tons of threads on nasioc bashing and loving them.

[loner]

group buy anyone?

[Guest]

Cant see any merit in them. Guess if you have a super fast car you can put a magnet on the roof and sell it as a proven 400m power adder special...

Ive given 5sp boxes hell and never broken one in anger.

[loner]

cheaper ones here https://www.apmtuned.com/store/transmission-reinforcement-plates

[loner]

 evowrx said:

Cant see any merit in them. Guess if you have a super fast car you can put a magnet on the roof and sell it as a proven 400m power adder special...

Ive given 5sp boxes hell and never broken one in anger.

if they stop the box flexing... there's your merit.

[Guest]

 loner said:

if they stop the box flexing... there's your merit.

Guess its awesome how theres no way to prove they work or dont. 5sp transmission failures are like nuclear disasters its human error. I sheared every tooth off one gear and every second off the other in a v4 sti box at 3k lazy changing to 4th in a 70k area. 5sp boxes dont fail from power. No clue how the box would flex or how one would prove it. Get a **** load of movement out of the mounts last thing to twist would be the trans. Guess it would pay to brace block as well heads hang out a fair way from centre line so more chance of that twisting with all that leverage...

[loner]

Synchromesh gears generate lateral forces... i.e. forces that push the sides of the box apart.

The more power you put into the box, the more the sides are pushed apart. That's why boxes with

straight cut gears can take more power... no lateral force. So extra bracing will obviously help.

[Guest]

...if they do actually flex to start with. I thought they were amazing when i first came across them on nasioc then i found a **** load of people who couldnt tell the difference or still killed boxes with them. Going back to 2012 iirc so may be some new development or change in them now that actually makes a difference. Everyone goes on about how r160 and 5sp are weak but plenty of people never have issues. Even 6sp break. I think theyre a gimmick but being a forum its all imo cant prove otherwise.

[Jono24]

 loner said:

Synchromesh gears generate lateral forces... i.e. forces that push the sides of the box apart.

The more power you put into the box, the more the sides are pushed apart. That's why boxes with

straight cut gears can take more power... no lateral force. So extra bracing will obviously help.

From what i've heard this seems exactly it, the opposing/separating force pushing the driving and driven shaft apart is the weakness in the 5 speed.

unless you are adding extra bolts, stronger bolts or additional preload to the bolts i don't see how this will overcome the separation force of the shafts.

This may address another weakness, but i don"t believe this to be the main weakness.

[loner]

 Jono24 said:

From what i've heard this seems exactly it, the opposing/separating force pushing the driving and driven shaft apart is the weakness in the 5 speed.

unless you are adding extra bolts, stronger bolts or additional preload to the bolts i don't see how this will overcome the separation force of the shafts.

This may address another weakness, but i don"t believe this to be the main weakness.

Yes I was thinking about the bolts needing to be stronger too. Possibly this type of brace addresses a very specific weak

spot on the 5 speed case... but maybe it's not effective.

[chulozumo]

Have also read it's apparently because the 5speed splits down the middle as opposed to how ever the 6 speed splits?

Interesting topic anyways, have basically been reading it's a real 50/50/Yay/nay/placebo type of thing.

Are all 5 speed cases exactly the same? Might rig some up for the hell of it

[loner]

 chulozumo said:

Have also read it's apparently because the 5speed splits down the middle as opposed to how ever the 6 speed splits?

Interesting topic anyways, have basically been reading it's a real 50/50/Yay/nay/placebo type of thing.

Are all 5 speed cases exactly the same? Might rig some up for the hell of it

AFAIK the v5 and v6 sti has 6 bolts on the bel housing... the earlier ones only had 4.

This seems to be true... my first v5 and v6 had 6 bolts... my current car has a v4

box and only has 4 bolts. The 6 bolt cases as supposed to be stronger due to the

extra two bolts which further resist the box splitting outwards.

[Tony]

The V5-6 (TY754) boxes are also a bit "meatier" in the casings with more ribs added. With a TY752 (v1-4) and 754 next to each other its quite noticeable.

[dmacnz]

I broke a 752 box at bugger all power. The 754 is surviving 300kw at the mo even a few launches. But I do try and look after it!

[GC8E2DD]

I launched the crap out of a 752 box for five years. Literally hundreds of launches. I broke it at an autocross with poor driving. I now have a 754 box of unknown history that I have also been launching the crap out of for 18 months or so. Still have the 5CA in the shed - should be an easy fix. YMMV