that's why that single setup that S&R did is very attractive...to ease the heat part for the 370Z guys you could cut vents in the hood over the turbo like the supra guys. Or a nostril like the 350Z guys.

525whp at 9psi has got me pricing out parts...

Where is the OP at?

Well STs got there car to make 480 in 7 psi seems pretty good to me and the turbo is at the back of the car,

Notwithstanding that you continue to completely miss the point (i.e. that generally speaking, engines work because of heat production)--controlling heat, e.g. dissipating it with the cooling system. For example, the cooling system can be upgraded to dissipate more heat so that the car can take more "beating." Beyond that I really don't understand what your confusion is.

Yea I missed the general part .. My bad

11k twin turbo miles and I've never went into limp mode, and I don't baby her either.

Great write up Mike! I enjoyed Thermo I/II and Heat Transfer as well, just hated the exams. You can throw Fluid Dynamics in there as well :icon17:

Thanks for the compliments everyone! I tried to keep this as fact based as possible. One thing I did forget to mention is that this dissertation was mainly related to performance and engineering.

I must concede that cost was not as much a part of the discussion as it could have been. A single turbo system does have that one, distinct advantage. Despite the lower cost, however, a single turbo is not half as much money as a twin turbo system. As such, a person must still factor in the cost/benefit ratio between a single turbo system and a twin turbo system. In some cases, the cost is the deciding factor, and performance is secondary. For other cases, the performance benefits are worth the incremental investment.


I'm pretty sure that my original post gave all the technical details that would ultimately establish my stance on any single turbo kit. You may want to consider re-reading it?

Turbochargers are designed specifically to operate in high temperature environments. If you look at any factory turbocharged car, the turbos are always mounted as close to the engine as possible. No OEM has ever mounted a turbocharger more than 5ft away from the engine (I think Subaru has the record on the turbo mounted farthest away...and the lack of performance shows).

There are places you want heat, and places you don't want heat. I'll go into more detail in another post.

The advantages of a single turbo were mentioned in my original post. However, the advantages are significantly outweighed by the disadvantages (as described in my orignal post).

The single biggest advantage of a single turbo is cost...not performance. ;)

Again, this is only related to V6 engines. If we were talking inline motors, we would be having a different discussion. ;)

True, and definitely something to watch out for with single turbo designs as not all of them are designed that way.

I'm not aware of any.

So far, I have not seen anything to the contrary. Again, as the single turbo's only competitive edge is cost, anything other than the reuse of the stock exhaust manifold would work against that advantage.

Until I am proved wrong, I'll stand by it. But unless someone can invent a reverse entropy device and defy the laws of physics, I'll be standing for a long time yet.

On a V6? It would require a substantial amount of number crunching to find that crossover, but from some of the numbers that I have looked at, I suspect my original estimate of 1300+ may actually be conservative.

You know, just for giggles, I shot an e-mail to a contact I have at Garrett just to see if we can get the actual MOI numbers. In his estimation, a pair of GT2860RS turbos will have a very close total MOI when compared to a comparably sized single turbo (GT4094R). Remember that MOI is based on the square of the radius.

Furthermore, due to the loss of enthalpy from a longer exhaust pipe routing (required for a single turbo setup on a V6), the twins will be receiving more total enthalpy than the single and since their MOI's are so close already, the Twins will respond faster.


That's a good question. It's been awhile since I looked at it. Keep in mind that the stock exhaust manifold has two ply heat shields as well. I'll see if I can dig up those calcs at home.

I'm back at work now. :hello:

You know, I saw that dyno graph. No boost graph, no AFR. The thing that makes me wonder, is when Tower only made 438 at 8psi before he installed water/meth injection. Something just isn't adding up. The lack of information and dyno graphs is not helping your case.

Whether you are running a single turbo, twin turbo, or a supercharger, the 370Z needs additional cooling. Period.

If we, as human beings, were unable to control heat, you'd be riding a donkey, my friend...not a 330hp sports car.

I'll be making a more detailed post about heat, shortly.

So twin turbos are always better? Is that what your ultimately saying?

Thank you for the information, and sorry if my question makes you pass judgment on another companies product.

I am saying that twin turbos have excellent response thanks to their proximity to the enthalpy source.

I'm sorry if you are looking for something that isn't there.

The reason tower made less I would assume is the auto tranny , chinook I think made 470 on 7 psi as well correct me if I'm wrong , another factor is tower left his stock cats in

Sorry chinook made 452 on 7psi

Your mistaken, I'll rephrase. Simply asking what you thought of their setup. If stressing the "IF" you did a single setup yourself on the HR/VHR how would you go about it. You can pm seeing this may be off topic.

:tup:

Tower the cost in a Tt setup is on the install time as well

To be honest with you, I would do something similar to what JTran Studios did. Maybe a different turbo choice and intake piping, but overall, very similar. The schedule 10 piping on the exhaust piping was a good call on their part...that and the fact that the piping is equal length so that the turbo receives evenly spaced pulses. The car clearly makes good power. It's just a little late spooling for my personal taste...but that's part of the trade off.

Because I like quick response though, I'd do twins all day, every day. I'm a bit impatient when it comes to getting that kick in the pants feeling from a turbo...I want it right now and for it to pull for days...from 3k to redline. Hell, I don't let my Subie drop below 3k rpms unless I'm stopped at a light.

Thankyou Mike!

I believe the first 370z to get an STS kit also had long tube headers. I mentioned about this a while back in the STS post. I guess it was ignored.

So most of the guys that are making more power with the sts kit are running HFC/test pipes and LTH.

Good to know...

Mike is correct, the twin set-up on our platform is superior for boost response, getting to peak boost faster and hopefully staying there throughout the rev range. Heat is essential for getting proper spool @ the turbo which is another win for a twin system, the turbos are right there. On my build we chose to use wrap and good piping to keep the heat temps up as much as possible in and around the turbo. I've learned a lot about both systems on the VQ platform over the years, for example if we would have run two smaller diameter pipes into a divided T-Flange @ the turbo we would have increased spool up time significantly and the next kit we design will incorporate that change. We also designed the system to be as A-semetrical as possible, keep everything even. Bottom line is price is the biggest attraction the single system has over the twin, I'm not going to sit here and say the single is better, even if I have one. I've had both and I loved them both equally. Like I've said numerous times GTM makes a quality part and you can't go wrong doing business w/ them. I just love turbos.... 2, 1 doesn't matter as long as it isn't a supercharger :stirthepot:

I plan on donking Ron's TT Nismo stg II after he's done w/ the install! :stirthepot:

Keep up w/ all the great info, I <3 LuRNenG!

Yes I mentioned that too and got ignored, he had some other stuff too. STS is just not worth it to me. Jtran's single is far superior IMO


http://media.animevice.com/uploads/0...158648_535.png

I know I noticed that as well, they make quite a difference and that would solve the cat breaking apart "issue" as well ......

ROFL, glad your back homie! Get that 3' exhaust in ASAP!

someone had mentioned s and r and there 5xx whp at 9 psi. there type of Dyno reads pretty high. a stock ctsv SC on that type of Dyno makes right at 525 whp. on our Dyno the same vehicle only makes right at 415 to 418 whp

Sent from my LG-P999 using Tapatalk

Interesting?

Ye I agree Dynos can be skewed

To Ron and O&G:

I want to be there to witness, lol. Drag strip or closed circuit? If it is the latter, I want in as well!

To all interested:

Now that's how you settle it, #s are nice but applying it safely at the track is what really matters!

True that

I'd be interested in more comparisons between STS and the twin setup.

The major thing I've noticed is that the STS setup looks easy to get running on the car (very appealing). The finished product of GTM looks a lot better imho.

Awesome write up Mike.

My STs setup will be here on Friday I will put together a good review for every one with lots of pics as well

you installing or a shop doing it?

Shop cause I'm doin headers as well , and I don't wanna do that lol

Nice! I'm very interested. :tup:

Shop quoted me at 2 g with install and tune me driving away the car they told me that installing headers takes almost as long as the STS kit

Sleepless nights ahead of you...trust me:excited:. The first pull you do will make you want more:cool:

I'm hoping to get 500 whp with the headers on 10 psi

it is not terribly difficult to construct one though.

you are neglecting the efficiency opportunities afforded by a larger turbo.



I always laugh when people make statements like:

and back them up with this:
rather than numbers. I understand you are running business, but isn't it good enough to just point at that there is nothing on the market that offers similar performance in a single, rather than broad, sweeping statements that cannot possibly be supported?

Can you share the numbers you've looked at? I would love to see them.



I understand that, but you don't necessarily increase the MOI a lot to bump up flow. You wind up coming VERY close in terms of total MOI, and the efficiency of a single turbo can get things very interesting. Turbine clearance needs alone create a huge opportunity for gains in efficiency, not to mention the pulse density.

http://www.ztechz.net/sitebuildercon...t28rs_comp.jpg
http://www.srtforums.com/forums/atta...-map-ghost.jpg


At some point this becomes trivial relative to other gains (pulse efficiency, etc). Obviously systems like the STS don't effectively leverage it.




I'd love to see them. I imagine the wrapped SS will be much better than you expect.

twin 2860rs are only good up to 550 at most whp. anything over that the intake air temp gets pretty high and pushes them way out of there efficiency. comparing two 2860rs to a single 4094r is absolutely ridiculous. a single 4094 will.make more power efficiently and with a lower iats then 2860s any day. yea you will sacrifice a bit on torque side but the top end side of things is pretty retarded. on 16 psi of boost on a 4094r on a rev up de with cosworth cams and port work, we full spooled a 4094r with a 1.06 hotside at 4100rpm. and was on stock headers and stock intake manifold. cam timing was mild in the midrange. spool up timing was at 9 degrees and it was on pump gas.

Sent from my LG-P999 using Tapatalk

We've made easily over 630+whp on the 2860RS' (VG30DETT). The highest around 670 whp. This of course is done on race fuel. At a mere 12 psi on a VQ37 they can make 550+whp (with the right parts). On setups\turbos that are inefficient you'll see the boost go up but the power gains are minimal and start to drop off drastically, this is a good sign the turbo is pumping heat. Contributing factors are not only the turbo but the supporting modifications for example the piping diameter of the inlet, outlet, and exhaust piping as well as the VE of the engine.

This topic can be discussed for ever, but in the end the ST kit still holds the top two spots:

1. InjectedPerf------04 Glide Enth 100 shot( IP 4.0L ) IP ST _8.801@159.19mph 1.485 60ft Dr's
2. Hal@IP -(daily)---05 6spd -Tour ------------(Built) IP ST _9.349@145.00mph 1.500 60ft Dr's
3. SoundPerformance -04 6spd -Enth ----------- (Built) SP TT _9.355@158.52mph 1.466 60ft ET Drag
4. need4boostz-------05 6spd -Enth ------(Built) 850s JWT TT 10.301@145.83mph 1.808 60ft Slicks
5. Bldrz ------------04 TH350 Base 50 shot (Built) Greddy TT 10.375@132.41mph 1.567 60ft Slicks
6. AudibleMayhem ----03 TH400 Tour 100 shot(Built) Greddy TT 10.404@134.00mph 1.729 60ft Slicks
7. neverenough ------08 6spd -Base ---------- (Built) GTM TT 10.673@135.70mph 1.677 60ft DR's
8. MRCMortorsports --03 6spd -Tour -----------(Built) APS TT 10.740@130.67mph 1.649 60ft Slicks
9. SnyperZ ----------04 6spd -Perf -LS2 w/Cam-Custom 88mm ST 10.840@138.62mph 1.852 60ft DR's
10. BriGuymax -------03 6spd -Tour -----------(Built) APS TT 10.967@126.84mph 1.587 60ft DR's

^^^ What is this chart from? Thanks.

"but in the end...." Huh? Complete race cars up there. The OP's premise starts at the beginning. I get your point, but it's irrelevant to a first time build.

Coop