I have a 418 with 9.3:1CR right now, Im thinking of selling it and running a forged 364(stock stroke 3.622) and whatever CR I need to make the most of the turbo I have. Either setup will have an "optimal" turbo cam and stall speed for the converter for what I need. You may say its prety cut and dry but the catch is I will be using the same turbo for either setup. I will be running an STS kit with FMIC and the gt67 turbo they sell which has a I believe a .81 A/R housing IIRC. Im not worried about out of the hole performance since I have a 2 step too to help the smaller motor out of the hole if needed. The reason why I even post this is because I dont want ot spin the 418 past ~6400 to keep some longevity to the motor, and Im thinking with the 364 properly setup I could spin it alot higher and still make usable power. Im afraid the turbo is going to be a furnace with the 418. I dont have the funds to buy a different turbo I could get one if I really wanted to but Im trying to focus on getting a house and wrapping up the truck mods for now. Also another benefit for going to the 364 is an extra 1K in my pocket after I sell the 418. If it matters any I also am going to be using a Vic Jr with the edelbrock 4barrel TB and stock 317 heads with patriot springs. Im really thinking of doing the 364 due to rpm potential and will help with shift recovery on a highway race. Im going to be making the final decision next week so I just wanted a little bit more experienced advice as to which would be faster.

 

bigger is better!!IMHO

 

more cubes=more power under the curve

 

street or strip? on the street bigger isnt always better...

 

It will see some track time but mostly it will be a street truck. It is 4wd so getting the power to ground isnt really a problem.

 

keep the 418, the torque and area under the curve is what will help you win the race.

 

are you saying the exhaust housing is a .46 A/R???!!!
you will have to run two if its that small, even then it still might be to small.
go with at least a .96AR

 

I think thats what is said, sounds small to me too, I know it has a smaller A/R housing than normal to help with spool time since it is a rear mount. Ill go out to the garage and check it out.

 

It has a .81 A/R housing dont know why I was thinking 46.

 

Anyone else?

 

The 6.0L will probably be the best setup for that particular turbo. The 418 really needs a bigger turbo than that.

 

I agree, maybe look at upgrade to the 70 at least. although thats also kinda small for your 418 also but at least your just upgrading the turbo not doing a complete shortblock $$$$. You should still be able to run 12-13 psi on pump with your 9.3 to 1.
Not for sure but I would think with the sts's long uppipe your going to loose some of the exhaust energy through the cooling of the gasses??????
You should still be able to run 12-13 psi on pump with your 9.3 1

 

Yes with the STS kit you lose alot of heat energy but they still work VERY well for use truck guys. Im not changing turbos. Im trying not to spend anymore more money at all to put more into my down payment on my house. I know the 418 needs more turbo by far but Im thinking if I limited the boost to what was efficient with the 67 that maybe it would make more power down low but then Im going to be rpm limited. I actually need less power down low to help out with traction even in 4hi. Just trying to get as many opinions as possible to help me make my decision a bit easier.

 

With a 6.0L built purposely for boost you should be able to take complete advantage of that turbo up top and run it in a more efficient range than the 418 will.

With a two step you should also be able to build enough boost at the launch to make up for the lack of cubes.

In the end I think they both would be about the same if the turbo is the limiting factor so probably just do whatever one is the cheapest for ya.

 

The turbo you have is way to small as XLR8NSS said. That is the size that I ran on my 4.8 liter and I was almost maxing it out with that small engine. I would suggest keeping your engine ( you are never doing to get back what you have into it) and run a S85 or S88 turbo with like a .81-.96A/R. That combo would make big power.

 

Im looking at 2K for the S85 with coated exhaust side like I want. Later on down the road I will upgrade for sure but it is going to be a LONG time(2+years) before I get to do that. Keeping the 418 will definately be cheaper. Guess Ill just run it and the 67 and have one hell of a heat pump. Maybe dual meth nozzles and some nitrous along with teh FMIC may crutch me along, just worry about bushings in the turbo then.

 

1slow01Z71~ I still think that you would be much better off not even waisting your time with that small turbo and run atleast a 76mm. Those arnt that much. You could sell the 67mm and use that money towards the 76mm. I think that you will be very disapointed with just how little power that big engine will make with that tiny turbo.

 

Ill see if anyone is interested in my 67 and see what a 76 is going for.