I was wondering what the difference was between the two:

APS Intercooled Single Turbo
Turbonetics Single Turbo Kit
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JWT Twin Turbo Kit
Greddy Twin Turbo Kit

My question is what are the pro's/con's of having a single turbo setup as opposed to a twin turbo setup?

If my assumptions are correct, both their performance. they are about the same because on the twin setup they two turbos are smaller than the single turbo setup.

Thank you guys for your inputs.

 

How detailed of an explanation are you looking for?

The simplest answer is in the lag. You'll get more lag from a ST system as opposed to the TT system. However, you have to consider your goals as well. ST systems have a bigger top end than a TT typically.

That's making a very high level pass. If you have more specific questions, you can probably get answers more to the heart of your question.

I don't have experience w/ any of these specific kits, but that's a general answer for a ST vs. TT difference.

 

MK said what I would have said. Just to reinforce...... a bigger turbo (Single) vs smaller turbo's (twin) will have more lag due to turbo size, more pressure needed to spool up for the bigger single turbo. So it would take higher RPM's on the same motor to spool. But on a single, once it is spooled, it would be more explosive power rather than the more linear twin setup.

Lag - The idle time for a turbo until it start to spool up
Spool - The time (area) in which the turbo is gaining speed (power)

During lag you will not feel any extra power. During spool time, this is where the A$$ dyno feels it planted in the seat and obviously once completely spooled up.

I don't have experience with t-kits on g35 yet either, but have on s2000, sti, and even with superchargers on other cars. Hope this helps.

 

Not totally true, APS uses a water cooled twin ball bearing Garrett turbo that provides boost at around 2,500 rpms for virtually no lag. The APS TT boost kicks in at 2,000 rpms only 500 rpms less!

 

SloG35 pretty much hit the nail on the head... The explaination can get really detailed.. I recommend Reading Corkey Bells book for anyone going Fi so you can understand all of the concepts of turbochargers. Like he said though the main idea is you will make more HP with a single....

 

- Well, I do understand the basic concept of having a turbo'ed car. I haven't seen dyno numbers between the two different setups yet.

- I was reading up on some newer "Hybrid Turbo" design's which incorporated dual ball bearing with ceramic turbine fins that would reduce the amount of lag significantly. Although, it is still under extensive of research I find it quite promising.

 

Twin - More expensive, more complicated, more plumbing (Oil , air and water lines)
Generally better response if the turbos are sized correctly, bling factor

Single - Less expensive, easier install, less complicated, less plumbing (oil, air and water line)
Generally bigger power at the expense of response, cooler intake temps due to lower boost levels

 

On the G35, the advantage goes to the TT over the ST. The TT's spool up faster, and have a higher torque curve that comes on much faster than the ST. Hence a more of a throw you back into your seat feeling. They also have less lag. The APS single turbo hasn't even been installed on a car yet so you can't go by the words that APS says. I want to see some dyno sheets. The ST is the cheaper way out for our cars. I'm not trying to offend anybody by saying that. But most of the people that are buying the ST's are because they're cheaper. The kit itself is cheaper and the installation time is cheaper. But if money wasn't an object, then the TT is the way to go. You can argue that the fastest Supra's are single turbo's but they also aren't a V6 engine. On a V6 engine, the twins are more sufficient.

 

Very interesting concesus by KjbAlto, thank you very much for your input. I also believe this to be true as well.

Another question is, I have a couple of friends that installed custom ST kits on their cars and have had a lot of maintenance cost. And being that TT is more expensive, how is the relability and most common possible break downs does one have? I'm most likely gonna do a TT setup because I'd rather have a better low end then to have a good high end.

"Torque wins races, Horsepower sells cars" Simply said, and something that I tend to follow.

 

there r twin turbo setups with one smaller turbo and one bigger turbo.... this setup is suppose to reduce lag and make more power

 

Hmm, interesting but here's a review from a guy who has a APS TT installed in his Z and has driven a APS ST and Turbonetics ST.....

07-01-2005, 02:01 PM #5
alpine
415RWHP APS-TT

Join Date: Jan 2003
Location: San Fernando
Posts: 756

In short, I would say the single setup is very nice, and if you want good power delivery, on a daily driver without huge HP goals or lots of moola, it's a good way to go.

I actually drove the car the day after the install was complete, this is while one of the guys from APS was actually on site @ brainstorm doing the install of the Single on the 350z and the Twins on the G35.

As some of us here know, I was also one of the few that drove the Turbonetics car before it was available on the market, courtesy of Brad Lewis, Vice President of Turbonetics so I've got a good idea how a Single Turbo "can" perform on a 350z.

All i can say is that the power from the APS turbo was available somewhat sooner and seem to be more linear in the delivery than what I recall with the turbonetics kit. The turbonetics came on soon & smoothly but as it neared it's "powerband" there was a noticeable kick (not there is anything wrong with that) wherease the APS just continued to climb in response to as much (or little) throttle you gave it.

In both cases, I can tell you that there is not anything that makes you feel like "damn there is lag" before you get response from the turbo/engine.

On my initial test drive I did make the suggestion to be more aggressive with the tune to bring in a little more power sooner than later, so that a "performance enthusist" type driver would get a better sense the "turbo is there" and fortunately they agreed and since have made the tune a bit more agressive, but it's still a great daily driver when driven as such.

As we all know, there is all kinds of opinions out there, some based on facts, (unfortunately most are not) as the way to make forced induction for the 350z.

Clearly APS has done considerably reasearch, and testing before delivering their kits, and I do believe it offers superior design (and some components) vs the Turbonetics kit, and essentially any super charger out there.

The right way to look at this Single Vs. Twin approach is the following, A single turbo is considerably better in comparisson to a supercharger approach for about the same money.

In both ST or SC setups, you can spend more money and make more modifications to the engine/supercharger to get more power. The HP ceiling is greatly increased on a Twin Turbo setup and you get power sooner due to the smaller turbos being able to spool up faster.

My setup works for me because I get more power sooner, and there is much more of a punch than in a single, and If I didn't have higher HP plans for my car I would not hesitate to pick up a single turbo setup from APS.

I do plan to take my car to the 500RWHP daily driver mode, (I'm currently at 400) and eventually a trick setup to allow for about 600 with the flick of a switch and 100 octane fuel

 

That is not true at all.....Disregard what this guy said please.. Someone should actually delete that.

 

Actually the only thing having a smaller twin turbo setup would do is bring the torque lower in the RPM range and make the powerband more linear. The single turbo powerband would shoot up like a rocket when it hits boost, and that what would give you the "Kick in the Pants" acceleration. As far as a twin turbo giving you more torque.. Thats is completley false, and I can tell is based on assumption.

 

Just wanted to point out there has been some first hand experiences of the different FI setups.

 

What are you talking about Nightmare??? Somebody should delete your post, not mine. Read the review that Brian even posted above. Everything I said was said again by the guy reviewing the ST kit. He said he gets more power sooner on his TT kit. You get more hp out of a TT and he even said that if he didn't want that much hp he would've gone with a ST. So from this guy's review, which Brian posted, the TT is superior in every way and he said the ST would be his pick after that, and then the supercharger. So please tell me what I said in my post that you said is absolutely not true and that somebody should delete my post??

PS - Go pick up SportZ mag and see what they review about the TT over the ST. The judges said that the Turbonetics kit kicked in for more of the higher rpm's while the TT kicked in early and was much more fun. They show you dyno's of all the kits and the TT's had torque curves very eary. Also pick up Road & Driver's Speed magazine that reviewed 4 turbo kits.