Chris_Boston

Hey everyone, this might be my frist post, I've been on FA and G35 Driver mostly. I had a question...

For my college graduation, my parents offered to "donate" a generous amount of funds so I'll be able to have the twin turbo kit installed. Here's my question...why isn't there a SINGLE turbo setup for the G? You would be able to achieve high amounts of HP (with internal modification), but is it because the twin setup is more of a "bolt on" friendly application?

TIA

-Chris

Soon to be part of the 400+HP club

SSR Engineering

Mainly because of space restrictions, companies that have put on a true equal lenth style single turbo system have had to mount the turbo on top of the motor near the firewall. Were others who have designed single turbo sytems use a simple cross over pipe and mount the turbo on one bank of the engine. If anyone is truly interested in a single turbo system, we can develop one.

NismoGCoupe

A single turbo kit with a T-88 would be real nice

NismoGCoupe

SSR, whats going on with your intake manifold did you do dynos on a NA car yet?

SSR Engineering

No, we are awaiting a car to finish the testing on. Our NA guys keep flaking out

NismoGCoupe

SSR why did you guys go with a Stainless Steel turbo manifolds? I would have been really interested in buying your kit, but I've heard many problems with cracking on SS manifolds

SSR Engineering

Stainless doesen't crack as often as most would think. SS is one of the best materials to use for manifold design hands down. We offer a life-time warranty against cracking and poor fitment with all of our parts, thats how faithful we are with stainless.

NismoGCoupe

you right stainless most likely would not crack on low boost, but i think once you start boosting in to the mid to upper teens your gonna run in to problem with cracking after time
you give a life-time warranty but that is not my concern, my concern would be the hassle to keep changing if the manifolds if they were to crack, You know how much of a pain it is to get in there

NismoGCoupe

sorry to get off topic of the single turbo, just curious why they went with SS

Loren04G35

There are obvious space limiations in putting a large turbo in the car, but you have to look at other things. To spool optimally and make the best power, you need the up pipes from the heads to the turbo to be as short as possible and as equal as possble. The is simply no centralized place to put a large single turbo in the car. The only area large enough is in the front bumper. If this was an in-line 6 cylinder like the 2JZ in a Supra, IS300 or SC300; a RB25-26 in an R32-R34 Skyline or even the 3.0L in a E36 M3 then there would be plenty of space to place that large single on the end of a custom header. But in our engine comparments, that space is taken up by a 2nd bank of cylinders.

That doesn't mean that Nissan didn't think about turboing. If you look at the are around the exhaust manifolds in our cars, there is surprisingly plenty of room to put a reasonably sizes turbo on each bank. In addition, there are water and oil access lines nearby to supply the needed fluids. If the turbo are placed up high on the manifolds then everything routes perfectly. This placement also gives the turbos good response and power capabilities. It was as if they intended for this chassis to support twin turbos. Hmmm...since the CPV35 chassis is the basis for the upcoming 3.2L twin turbo R35 Skyline, this shouldn't be a surprise.

On the stainless steel issue, first cast iron is the most tolerant metal of deforming from heat. This is why almost all OEM turbo setups use cast iron manifolds. They are also expensive to design and produce unless you are making large quantities. The mold costs are $10-50K per casting. The castings always have a rough appearance unless a separate process is used to finish them further. OEM, this is never done. To just bend stainless steel or aluminum is far cheaper in small quanitities. There simply isn't much development cost to absorb. Higher grades of stainless steel have good heat characterististics and with their smoothen surface will flow more.

Cracking can be due to several issues: using too weak a material for the heat, using too thin of material, improper welding and resonance harmonics. The first 4 are obvious, but not the last one. Remember that a manifold is attached to an engine that has a recipricating assembly inside constant turning. Each cylinder is basically making a cycles of small explosions igniting fuel and air. the exhaust coming out of the head is moking in rythemic pulses. Each of the harmonics have to be absorbed by the manifold. If 2 turbes run closely together, but aren't welded together like a seam; these harmonics can actually cause the tubes to oscilate against each other and form a crack between them. If the manifolds are designed properly then you will never have a problem. RPS and Greddy single turbo headers for Supras are well known SS headers that do great jobs without problems cracking.