You bastards!

I should find out tomorrow if I'm getting one or not.

 

How low does that cross over pipe sit? It looks low.

 

I assumed you would need a lift and some mechanical ability, but what do you have to fabricate?

 

..Nothing in this world is perfect, including turbo kits. I guess fabing is too extreme a word to use, though we did fab a clamp for the missing 3" v-clamp. There are things you just have to use your head about in the instructions. Components they state to install first that make it more difficult then if you installed of left out to later. FYI
mount your pwr steering cooler above the intercooler, not per instructions and you will grab more air.

The system is complete as of Sunday AM, have boost issues that we think is a stuck b/o valve. Our day off, we will deal with it tomorrow and hopefully give you all some dyno #'s.

 

While Peter is away, I thought I'd have a browse over the forum to see what's happening.

I must say that I was surprised to see cross-over pipe sitting so low and so far back. Because I am and work as an Engineer I have just spent the past hour or so thinking about why one would route the pipe all the way down under the gearbox and then back up to the turbo and frankly I can't come up with a technical reason - when it would be easier and more effective to go up and over the bell housing. Over the bell housing will result in a shorter distance (better turbocharger response). There's more than enough room over the bell housing for the pipe and an over abundance of heat shielding.

In addition, because it's so far back and below the cross member, surely it will be very vulnerable to impact damage.

Mia, are you able to ask why it's routed like this? Is it like this for the first production run only and then future production runs will go over the bell housing? Is it for cost reasons? I'm not trying to be provocative Mia, just genuinely wondering why Turbonetics (who I respect greatly) would go this way.

George

 

subscribing......

-justin

 

Isnt there a waterline above the belhousing that goes to the back of the head?

Sorry its actually on the other side

 

I couldn't say why it goes under but it is by no means low.... The flange connecting my exhaust to the down pipe is MUCH lower then the crossover pipe and that flange is in the factory location. The corssover pipe on the Turbonetics kit is not too much lower then your turbo from the pics Ive seen

 

Hmmm... I'm still at a loss as to why one would go this route. I mean, we looked at going under the gearbox for the APS single turbo over a year ago now (geeze where's the year gone...) to minimize cost but decided against it because of the exact issue I see here - where every inch of ground clearance on a lowered Z is desirable.

For example in the picture below, the impact shield on the APS single is higher than the cross member of the stock car. Perhaps the pictures of the Turbonetics single are misleading because I know how difficult it is to photograph this area, but by the look of it, you couldn't even place a shield around the pipe because it hangs lower than the cross member.



Call me naive, but hanging a cross over pipe that will transfer the impact shock to the entire system so low and so far back when a preferable alternative solution (in terms of clearance and performance) is available still doesn't make sense to me - hence my original question about whether this will be addressed in future builds of the Turbonetics kit.

If you get the chance Mia, quiz Brad on it since I do understand that ground clearance is an important issue to you and some members.

George

 

Translated:

After all that debate (screaming!) about low parts on the APS ST, it's funny that the Turbonetics kit has parts that are even lower and unprotected.

 

I beg to differ.... actually I don't see how it would scrape on anything. The pipe is really not as low as you think it is... I looked under the car again last night the lowest item on the car in the front is the cross member. The stock debris shield would techincally cover the crossover pipe if it went that far back. Furthermore I did think of one reason why it goes under although I need to confirm it with Brad... By running the crossover pipe over the tranny you are effectively heating the upper and lower side of the transmission. Heres what I gather:

When the pipe is run OVER the bell housing it has a distinct lack of air flow for cooling. As a result you are increasing the ambient temperature of the upper bell housing greatly. After all EGTs are close to 1000 degrees farenheit in the pipe. Furthermore by having your turbo so close to the lower portion of the bell housing and adding that heat shield you are reducing the air flow that would cool the turbine housing of the turbo therefore increasing the ambient temperature near the lower bell housing. By doing this you have effectively increased the operating temeprature of the ENTIRE transmission and allowed for LESS cooling via airflow. For a $1500+ transmission that already has a chronic history of failure this would worry the hell out of me. I'll take my chances with a possiblilty I MAY scrap the crossover pipes slightly (I haven't yet and I know I have scraped the underside of my car several times recenty over speed bumps and the alignment rack) then have my transmission fail due to overheating and have to pay for it.... Furthermore at least if I do somehow damage my crossover pipe or turbo kit (not likely since I haven't yet through all the beating its been through) Turbonetics will replace any of the kit items free of charge regardless of how the damage occured. If I kill my transmission Nissan isn't going to be so willing to help.

 

i guess the big test will be, how both kits hold up on cars over a year or so.

 

I’m glad you brought this up because it also concerns me of the additional heat round the transmission with both APS and Turbonetics ST. This concern only has caused me to shy away from the ST even though it is my first choice, second being TT setup. After reading an article in a turbomag about causes of transmission failure, I’m now leaning more towards a TT setup. My other option is to wait a year until the buyers of these ST kits can vouch that this is not a concern.

 

I agree that heat near the bell housing is a problem...at leat the Turbonetics kit has quite a bit more air flow over the crossover pipe then other designs...

 

I can, it's easy.

There's a hump, which is at the same height or higher than the front cross member or rails. The front wheels climb over the hump thus clearing the cross member, the front wheels come down the other face, you travel a foot or so and bang-o (technical term). Remember the shock load is transferred to the whole assembly, not just the cross over pipe. The lower and further to the rear the cross over pipe, the higher the likelihood of impact. I can't understand how after the fuss you made in an earlier thread about ground clearance that you're now happy with even less clearance and even more vulnerability with your lowered car (which looks cool by the way).

Huh? We are talking radiant, not convective heat. It’s radiant heat that you’re trying to limit and modern heat shields do that very effectively by reflecting the radiant heat back into the pipe. It’s not cheap, but it is very effective indeed – and well worth the cost.

The picture below lifted straight off the APS single turbo web site shows the heat shielding (the crinkly stuff - again another technical term) around the pipe which goes up and over the bell housing.



The whole idea is to keep the heat inside the pipe because the turbocharger relies on having all the exhaust gas energy (yes heat) reaching it in order to operate efficiently. To see a pre-turbo exhaust pipe on a modern turbocharged vehicle without efficient heat shielding is very rare. In fact I can’t think of one at the moment.

I have taken it for granted that the images shown here of the low slung cross over pipe are with the heat shielding removed - right? I find it hard to believe that such a hot pipe would be wound around the Z's gearbox without proper heat shielding.

If on the off chance that there isn't heat shielding, a word of warning. Other than the high radiant heat load directly into the gearbox, there is a high chance of fire if you pull over onto the grass verge of the road after a hard run.

Be careful because regardless of your allegiances, I hate to hear of anyone damaging his or her Z.

If you really are worried about gearbox heat Mia, I would suggest that you investigate sound heat shielding sooner rather than later. The high radiant heat load over such a wide area where the cross over pipe wraps around the gearbox would have me losing sleep too.

Precisely. This is one reason why one would route a heat-shielded pipe over the bell housing and not the gearbox itself.

George

 

.......... ..Ouch! My thread has been hijacked.LOL

...I agree on the heat issue that APS mentioned, velosity dynamics though may not make much of a difference. I don't know, I never did a model study on this reaction.
Mia is correct about the clearence of lower trany cross over pipe, my car is lowered 1.5" with Tien suspension with no issues.
There are things that need tweeking, trimming, pulling, pushing to function, this will avoid addition noise or fibration from components and chassis.

....What is the purpose of that large weight on the swivel bracket/rt front side....???????

Anyway, the boost leak was from the turbo down pipe to the 90* to intercooler. When corrected car boosted and runs very strong(rips 275/35-19's loose on 1st to 2nd gear change under full throdle) and has good boost feel. We will get the car on the dyno tomorrow and check A/F and boost, I think at this altitude we are only getting about 5.5. It just doesn't feel strong enough to me at this point, but those that know me that might not be a surprise.
Will keep you posted, Zietronics and Greddy on the way.....

 

George,

Does the APS ST kit come complete with heat shielding wrap?

 

Absolutely it does. Each section is pre-trimmed to shape and size much like the way it is with the APS Intercooled Twin Turbo System (the installation instructions on the APS web site show it in diagrammatical form). Also, the shielding is actual shield, not heat wrap and it's there for the life of the car.

George

 

You should start an APS thread for APS ST discussion, for everyone's sake.

 

.........................PLUS 1...........................