4D55/6 ARP Head stud part numbers

[JeffTheMarine]

I've never seen this published anywhere so here's for anyone wanting to get rid of the torque to yield bolts.

ARP STUDS part # AU4.950-2UB

ARP NUTS part # 300.8308

ARP WASHERS part # 200.8500

You will need 17 of each

Jeff

[JeffTheMarine]

Correction 18 of each

[MainstreaM]

Might be a good idea to add this to the parts sticky

[skullzaflare]

Bumping/adding to this. I had been contacting ARP through email, they do not have anything documented for the 4d55/56, however from measurements, here are the numbers he gave me

Stud
Au4.600-2b m12x1.25 to m12x1.75 by 117mm
$16.92 each

Nut
300-8376 m12x1.75
$5.38 each

Washer
200-8500
$1.19 each


REVISED, As of current, the tech changed his mind after i asked about clamping force with the 1.75 threading, to which he replied that he agrees that he would not trust the 1.75 up top.

[pennyman1]

That makes no sense - they are ARP studs, way stronger than any factory stud / bolt, and they don't trust it? Then why are they selling it?

[geezer101]

That makes no sense - they are ARP studs, way stronger than any factory stud / bolt, and they don't trust it? Then why are they selling it?

You know how there are 'experts' who 'know' what they're doing? I would think that ARP's tensile strength testing of 170,000 psi would be up for it (304 stainless - the UTS version of the same studs are rated 270,000 psi) The, err, 'best' chinese equivalent would be down at least 30% of those figures...

http://arp-bolts.com/p/technical.php

[dancinggecko]

I bought a set from them, the guy I spoke to said that that part number was made from there 200,000 PSI tensile strength ARP2000 steel. He asked what I was using it for and said they ought to hold up great. I've been running them now for about 6 months with no problem, just wondering how my factory turbo is holding so much boost...

[geezer101]

...just wondering how my factory turbo is holding so much boost...

You know that Mitsubishi turbos get sourced as replacements for use on other vehicles? The Porsche guys rip the KKK turbos off their engines and use factory Evo ones, too funny
(don't know if it's because the Mitsu turbos are geniunely superior or they feel bad about getting their asses handed to them by guys in Evos and will try anything :lmao:)

[skullzaflare]

That makes no sense - they are ARP studs, way stronger than any factory stud / bolt, and they don't trust it? Then why are they selling it?
The thought is, those studs i listed are being flipped over and used the wrong way.
12x1.75 into the block would be using all the threads, but flipped it will only have a 3/4" nut on it. Far less surface area to grab than a 12x1.25

You know that Mitsubishi turbos get sourced as replacements for use on other vehicles? The Porsche guys rip the KKK turbos off their engines and use factory Evo ones, too funny
(don't know if it's because the Mitsu turbos are geniunely superior or they feel bad about getting their asses handed to them by guys in Evos and will try anything :lmao:)
They do last a lot longer than most turbos, side note the stock turbo didnt even last a week at 30psi, but thats because i dropped throttle to fast in a quick panic and bent all the blades

[skullzaflare]

I've never seen this published anywhere so here's for anyone wanting to get rid of the torque to yield bolts.

ARP STUDS part # AU4.950-2UB (Only part number i have found and to be sold in singles)

ARP NUTS part # 300.8308 (OP is sold in singles), 300-8328 (pairs), 300-8338 (10 pack of same nuts)

ARP WASHERS part # 200.8500(OP is sold in singles), 200-8537 (10 pack of same washers)

You will need 17 of each

Jeff

Going to add extra info in here
Prices i have found.

Autoplicity
Stud AU4.950-2UB $12.87/ea

Single nut 300-8308 $5.80/ea
2-pack nut 300-8328 $8.14 ($4.07/ea)
10-pack nut 300-8338 $43.01 ($4.30/ea)

Single washer 200-8500 $3.99/ea
10-pack washer 200-8537 $9.37 ($0.94/ea)

SummitRacing
Stud AU4.950-2UB $26.99/ea

Single nut 300-8308 $3.99/ea
2-pack nut 300-8328 $8.99 ($4.49/ea)
10-pack nut 300-8338 $41.99 ($4.19.ea)

Single washer 200-8500 $1.99/ea
10-pack washer 200-8537 $8.99 ($0.89/ea)


For some reason the single nut is the best deal on summit in singles....as dumb as that sounds
Directly from ARP i was told through phone sales i can get the stud for $17.79/ea, single nuts $5.38/ea, and single washers for $1.19/ea. Now finding numbers for the 2 and 10 packs, it MIGHT be a better deal directly through ARP for that, but i cant say for sure.

Dont forget the recommended lube (not for your wallet) 100-9908

[weelsey]

As far as I know the 4d56 do not use TTY head bolts. Do I have bad info?

[skullzaflare]

As far as I know the 4d56 do not use TTY head bolts. Do I have bad info?
i have had mixed results in my research, but a the same time 3 separate retorques i have had bolts come loose

Now to be fair i am running 2 turbos and 30 psi lol, i went through 2 headgaskets in less than a month, no issues since ARP

[gustycrosswinds]

does anyone know the ARP kit number for these? i was told the 207-4205 kit might work.

[dancinggecko]

I don't believe there is a kit number for this. I just called them and gave them the part numbers I needed

[weelsey]

i have had mixed results in my research, but a the same time 3 separate retorques i have had bolts come loose

Now to be fair i am running 2 turbos and 30 psi lol, i went through 2 headgaskets in less than a month, no issues since ARP

And we should be running the updated 4d56t head gaskets.