I was viewing the web site www.turbochargers.com and noticed when it comes to the mazda rx7, all they offer is rebuilt turbos. I thought you could upgrades both turbos with larger ones. Guess not, so is this why everybody goes to the single setup instead?

 

Not true, you can upgrade the size of your turbo's. I have no personnel experiance about this. However, I am going to put on a larger secondary turbo on my RX-7. I am also going ball bearing on both turbo's. I have heard of people upgrading the size on both turbo's However It is way more cost effective to go single turbo if high horsepower is what you are after. Also there is a size issue Two big *** turbos will plainly not fit. I am sure someone with more experiance than I will explain combinations of turbos commonly swapped out with the stockers. Hope this helps.

 

i woudl not get a larger secondary turbo, u are gonna have lag, and boost problems most likely at the crossover point, just get the 99 spec jdm ones if anything....my .02$

 

I did a post on another forum about single vs. seq-twin vs. non-seq-twin vs. seq-twin-with-bigger-secondary. Here's the link:

http://+++++++++++++++++++/forums/sh...&threadid=1051

Being short:
Single turbo = Power, lotsa lag
Non-sequential twin = Less power, but less lag
Sequential twin = Low lag, less power
Sequential twin w/ larger secondary = BOOST SPIKE

 

did anyone see the TURBO magazine with the orange FD on the cover,, it was a couple of months ago.. anyhow,, he had upgraded twins, i forget what size though.

 

You can have your turbo housings machined out a little and put larger compressor wheels in. That is what an upgraded twin turbo is. They can be made to flow about 20% more air.

 

Hmm. Someone didn't like my link... I could post the actual text, if anyone is interested.

 

Aight, guys..........Im gonna make this really easy for you. Twins have not been able to be enlarged realiablly. Therefore, you have one true choice if you want real power. Single turbo. There are many good things that come with going single.......ie...no vacume line bs..no selanoid bs...,no sticky turbo issue's, Hell no reliablity issue's at all. If you want a good turbo that makes decent power and won't break your piggie bank, go w/ the T04E, Apexi RX6, or KKK(stage1). You won't be able to run your air pump, but just take $100 bill w/ ya to the emissions station... You'll be fine. As far as the lag issue goes, don't wine. If you race your not below 3k are ya??? Thought not. Most of the smaller single turbo's I mentioned are gonna spool fast anyways.

 

You can't go back

 

no that last comment-- you can't go back--- is that true-- once you go single you cant go back, well ok--- if i choose to go single --- what other mods will i have to do --- a know a upgrade on the intercooler ---and also for the guy who converted --- what was the conversion price, tubes, lines and so forth.???

 

you need the turbo kit, stand alone ecu, fuel pump, injectors, hoss clutch, flywheel, ic, probably want a port job done, and I think that's about it...with a greddy t78 I have priced it around $9k for everything and then throw in a couple hours of dyno and tuning time and you are around $10k

 

I think what he means is that you will be soo addicted to the speed and power of a single that you will not want to go back

 

If you go single, you cannot pass emissions...is that true?

Ernie said you need $100 for the emissions guy....I can't get away with that in Ohio.

Is there any way to have the car pass emissions WITH a single turbo...WITHOUT paying off the emissions guy?

Patrick

 

you have to eliminate the air pump to install the single turbo...once that is gone it does no good to have a cat and no, u will not pass emissions

 

man no cat for me -- oh no --got probs.. oh well

 

Actaully there are a few kits (HKS) and maybe some others that will allow for the airpump...

 

I was unaware...thanks

 

I thought one of the tuner shops came out with an emission legal single turbo kit that also has a piggyback
off the upgraded ecu of your choice w/o standalone management ?

 

This is true. HKS is the only company that I know of that has this kit though. Dragon had it on his car for awhile so he could pass JCI(Kind of like a yearly emissions test, but every two years).

Even if I had emissions though, I would still go single turbo. turbo lag and all, there's no better feeling than the wastegate opening up when your car spools at 4500 rpm's and as you pass your competition, he's looks because he thought he was fast

...and if you don't want turbo lag...get a t-04e or a t-04s with a .84 exhaust and .50 compressor...just enough for the stock injectors and still WAY faster than stock twins.