Also wouldn't the single Turbo make more power than the Twin Turbo for less money?

 

did i see some one mentioned TURBO LAG?

 

I don't believe its practical to package a large enough single turbo within the space available. And even if you could the boost curve would be quite ordinary, similar to a centrifugal supercharger. A twin Turbo system is the ideal configuration for a V6 engine and will generate the best torque and power possible.

Peter

APS

 

This could be argued for days, weeks, years. Same goes for which is better turbo or supercharger.

 

Really. which part would you argue about.

Peter

APS

 

Plumbing the sides together would be nearly impossible, unless the hood were bumped up and the cross-over took the high road.
One issue with a single T on a V engine is that turbo's efficiency drops due to the poor heat coupling from the far bank's exhaust. The best efficiency is obtained when as much exhaust heat can be coupled from the exhaust ports into the the impeller inlet.

 

Someone tried, and failed. The engine compartment is too small. But yes, a single turbo will make more power than a twinny.

 

it depends on your goals honestly....there is not "better" IMHO, there is better for your application

There are quite a few single turbo 350Z's out there in the world right now....and the reasons behind them are numerous.

I agree with Peter thought that for driveability, the twin is the route to go.

 

Just strikes my curiousity why we(America) cannot come up with a single turbo solution like the Japanese have(topsecret)...besides the reason it's a Japanese car

 

I am surprised at your comment regarding the single turbo will make/generate more power than TT system. Im my experience the engery loss in plumbing the exhaust gas (energy) from one cyl bank to the other really hurts the potential power of the single turbo application. If you spend some time on engine dyno and measure both types ( that is single V twin turbo) I am sure you will quickly see what method of turbocharging is clearly superior on a V configuration engine.

Peter

APS

 

Well, on a V configuration engine, the twin is the easiest to do. Guess the main reason that someone would want a single is for less parts to go wrong and lower price. Top Secret has proven that it can be done though, so it shows that none of our manufactors here dare to be different and make it work here, instead they produce 50 very similar twin turbo kits, lol.

IF that calls out all you guys producing the kits, so be it. Be different, fill a niche and make some money.

 

I wouldn't say the TT is easier than a single turbo in fact the twin set up is far more complex (we have done a single turbo on the Z car). The TT system is much nicer to drive compared to the single turbo, and you have the opportunity to achieve the CARB EO which would never be the case with a single turbo arrangement. If you drove the single turbo then compared that to a well engineered TT I am 100% sure that you'd pick the TT every time.

Peter

APS

 

Well, I am sure if I drove a single turbo then compared it to a well engineered TT, I would choose the TT. How about we make them both well engineered. Just kidding, lol.

CARB means very little to me, and there are others who would agree with me of course. I know how inportant it is in Cali, but if Top Secret can run a single in japan, seems we could make one for here. There emissions requirements in Japan are pretty strict too. I know the TT is more complex, but I was just speaking in terms of the plumbing for the single turbo.

Peter, I understand your viewpoint, especially with your TT kit coming out soon. Your kit is nice, believe me, but you have a whole lot of competition. A single turbo has no competition in the US. NONE. Lag issues are always brought up, but lag isn't always a bad thing if you know how to control it.

It would be nice if we had a choice, that is my only point.

Kinda like McDonalds forcing us to only eat breakfast before 10:30. I want my pancakes for dinner.

 

There are good reason why every OEM V-engine turbo system use TTs, evn now in 2004.
It certainly isn't cheaper to implement TTs , but it does make a more street friendly setup (ie smaller , quicker spooling Turbos) and it make CARB possible. Not to imply that OEMs provide "fully optimal" solutions.

Now if your objective is pure offroad performance , no CARB, less TQ below ~4k not important ,then peak gains can be made better with a single large turbo. The main diff being that the efficiency island occurs at a higher flow volume with the single big T vs. two smaller Ts with islands lower down.

 

Yeah, G3po, really I was thinking along the lines of comparing a ST to a certifugal SC, only cause the cost could be similar if you add headers to the SC, with install for each one. The power curve for the ST would be more peaky than a TT, like you said, but you would have substantially more low end torque than a certifugal SC(which is also peaky). The ST and SC w/headers could be similar in price installed, with the ST putting up alot more power on the low end cause it can hit max boost so early. Depends on the price of the ST, of course. Just a thought.

I am interested to know why a single would make CARB so impossible to attain.

 

The reason why a single Turbo on an VQ would be difficult to meet CARB is that the excess heat loss in the "long cross pipes would not allow the CAT(s) to heat up rapidly enough and hence violate the CARB cold light up requirement. Also not that both CARS must remaoin intact which also causes a plumbing issue (1 Turbo branched to two CATs.

The light up requirement is one reason why all new autos place the CAT(s) as close as possible to the exhaust manifold. They need to get the exhaust heat as quickly and efficiently as possible to the CAT(s). Long pipes won't cut it.

 

I know how inportant it is in Cali, but if Top Secret can run a single in japan, seems we could make one for here. There emissions requirements in Japan are pretty strict too.

They also have higher octane pump gas then we do...I think 98 or 102 at the pump isn't that sick?