Quick question for some of you experienced guys...

At what point does it really become necessary to upgrade to the .625 rod bolts?

I currently have Manley I-Beam Turbo Tuff rods for my turbo GSR and I really dont plan on making more than 700whp and dont want to rev past 8700 until I learn to drive the car consistantly.

Its also my understanding that there is a little bit of machine work that will need to be done to the big end of the rod to accept the .625's.

Are there any of you guys who have pics/part numbers of your .625 bolts and maybe a pic of the finished product installed? I havent had much luck searching for information about this, just doesnt seem like there are alot of guys going this route or something.

Thanks in advance guys.

 

Also- I am running a Oem gsr crankshaft.

 

Interested too.
Any advices?

 

Might have better luck in the drag racing forum on this one.

 

The reason you'd need the aged 625 is due to rod weight, piston weight and high rpm.

The goal is to prevent rod cap separation, which is exactly why you would want to upgrade. For Manley TT's I would use the stronger bolts, but that's just me with a drag racing mindset.

What pistons are you using?

I use ARP 2000's on my aluminum rods with great success. Many make 1100+ with these and it's not a problem. Only difference is rod/piston weight.

Also, when you order the Manley TT's all you have to do is add an "R6" to the rod part number and it comes fitted with the 625 bolts.

Part number, if I remember correctly, is 42321.

 

OK thank you for "R6"
I'm using CP Pistons

 

That's good information to know! I wish I knew that before I ordered my rods. I just stuck with the 2000's on this last build.

As far as pistons go, I am running a custom JE full skirt piston which are probably heavier than any shelf piston out there. I haven't been revving it past 9k but I do need to bump the limiter up to 9500 this year. Lets see how these 2000's do!

The next engine I build will be an Aluminum rod engine though, just makes sense since the car will only be seeing the track.

 

Just make sure you're using the heavy wall piston pins and you'll be fine. Try not to use the motor to brake after making a hard pass and the rods should be just fine.

 

Yep! They are the heavy wall wrist pins.

I don't ever use any engine braking after a pass, I usually throw it in neutral and wiggle the stick from side to side like 34 times while I brake. Lol.

 

LOL, we have a winner!

 

Haha. It must be a nervous habit or something...

 

+1 for the neutral wiggle!

Do you have a part number for the bolts you use? 3/8"?

I for the life of me cannot figure it out