the_glass_man

iTrader: (2)

I need opinions and or recommendation's on a single turbo. I'm looking for something I can use in a daily driver or in a street car. What's the best for streetable horsepower with minimal lag? Also what is the best for the price. I'm considering all makes from Apex'i, HKS, XS, and Greddy. I'm leaning towards the T78 from Greddy. Any more reliable than others? I will keep my large M2 Stock mount intercooler and will probably use and Power FC for ECU. Any Opinions would be greatly appreciated.

94touring

I think that most will agree that the apexi is the best for the street. It doesn't have the potential that the greddy has when it comes to top end performance, but spooling up quickly and being capable of producing 400rwhp on the street for a daily driver isn't bad.

spyfish007

I've heard that the 400 RWHP on the Apex is a lie! It has a very big compressor with a very small turbine housing, so it comes up quick, but dies up high. It peaks out 500 rpm less than the twins, but at every point the the HP graph (comparing same boost level) it has a higher HP and torque numbers. Now the Japan version on the other hand has a bigger turbine housing and it is supposed to make 400+ RWHP.

1FooknTiteFD

someone advertised the apex kit that at 15 psi it would produce 400rwhp. However, I know someone who boosted 15psi on the dyno and only got 360, the guy had a ported motor too! what's up with that???

94touring

Let me just say this. You can't just slap a single turbo on and expect 400rwhp, you have to have your **** right.

spyfish007

Ported motor will make that it worse on that turbo. The turbine house is just that small! I think the kit is rate 400 bhp, not rwhp?

94touring

Spyfish007, I am not trying to be an ***, but I would like to know where you are getting your info from. Please fill us in

HWO

one word: TUNING

spyfish007

A dyno sheet I got from Chris Ott at RP. He printed out the sheet for me and told me about all the mods/tuning on the car. Other thoughts about turbine house size are from Ari and this forum. I have talked to several people about this turbo at one point, because I was really interested in it. It pulls so hard down low and mid range rpm you eyes are like wow! I was just wish it made a little more power up high. Chuck 'N Seoul (spelling?) has this kit if I remember correctly, but he is overseas and has the big turbine housing (AR = 1.15) and he pulled like 415 RWHP. The american version is the RX6 not the RX6B. I think Ari has been trying to get the overseas kit . . . I don't know if he has had any luck though.

94touring

Thanks for the reply. The only thing that doesn't make much sense to me is that a street port will make the turbo worse. How can a street port increase the hp on the stock twins but not the apexi turbo? Even if the turbine housing is small it isn't that small, defenitly not smaller than the stock twins. I still need to dyno mine, haven't even gone to the track with it yet cause I am rebuilding my engine. However a friend of mine used the apexi turbo also when he had his rx7, and was running mid to high 11's at 15psi. He never dynoed the car, but if he was hitting 11's it had to be around 400rwhp. I still think it is the best for the street.

wptrx7

hey guys keep this thread alive. i am stuck between the xs turbo kit (t04s) and the apex turbo kit. i visited local shops and they do agree that the apex is the best for strictly street application,but i've heard that if the kit breaks(?) you would have to replace everything with a new kit. maybe there is something that i am missing but i thought all turbos are rebuildable. the xs t04s seems like a logical choice to because it provides you with more hp at a least expensive cost, but it spools up slower thatn the apex kit. please feel free to shine some light on to what i just said and share your opinion. i have a stock fd, lookig for a single turbo kit. by any means i do not have either one of these kits and have no experience with either kit. what i am repeating is what i have been told be authorized dealers of both the xs t04s kit and the apex kit. i am trying to find out from someone with either of these kits to let me know how they feel about the kit they have and an honest feedback. and any but xs power, we know where you stand. thanx luigi

Sidestick

iTrader: (1)

Hey Luigi, I too am considering a single turbo kit and am trying to decide between the XS T04E or T04S. The E for it's throttle response, or the S for it's HP capability. I am leaning more to the E for it's streetability & expecting about 380ish hp or so on my stock engine at 15psi. However XS has told me some extra horses can be had by getting the turbine housing upped to a 1.00 size (20hp I think) at a slight decrease in response. I think I can live with that to achieve my 400hp goal.

I'm not considering the Apexi due to what you mentioned in your post; the Apexi is not rebuildable (parts unavailable in the US I guess) & a new turbo is about 2000.00.

spyfish007

Ok, I could be talking out of my rear end at this point . . . but I'll try to explain.

A ported engine will help you to a certain point (power/flow level). Once you cross that point the back pressure in the exhaust manifold becomes to great and you really can't get the air out of the engine, so power starts rolling off. To take advantage of a ported motor you must have a larger turbine housing than you normally would. Unless you have really big ports you really aren't going to make power in the 7/7.5k and up range. I've been told (once again, no real experience here only explanations) it is difficult to make power in this range. If you remember the car with the controversy from XS, then you would also know it has VERY large street ports and it makes power in the 7k to 8k range. I have seen RiceRacing post before about not many people knowing how to make power about 8k. I suspect this is the reason.

Oh yeah high/mid 11s in the 1/4 mile is right about 350/360 RWHP which is very believable on that turbo. Low 11s is more like 400 RWHP.

LongRX7

iTrader: (12)

I am thinking about going single also. I was initially leaning towards the Apexi, but this thread says it is not rebuildable. I wondering on the horsepower differences between the XS kits the T04s and T04e. I have a stock engine, no porting and stock 2mm seals. Would either one of these kits fit with a Blitz FMIC? Anyone have dynos of either one of these kits? Trying to learn as much as I can from this thread, so I can decide which one to get. Also would the Greddy T-78 have more or less lag than the T04s?

Current mods:

stock engine and seals
Rotary Pro Pak ignition
Pettit Underdrive Pulley
Blitz DSBC
RP MS midpipe
Blitz Nur-Spec
Rotary Performance ECU(ya'll didn't know did ya'll)

I left out some things that would have to be replaced if going single, ie..downpipe and intake.

LongRX7

iTrader: (12)

Damn, using the scroll down feature at the RX-7 Store answered the HP question. Another question, what if anything else is required to purchase to install these turbo kits. XS engineering ones.

wptrx7

from ,my understanding both the xs an apex kits come with everyhting you need as far as bolting on the kit. apex uses all apex products and xs uses products from different manufactures to make up thier kit. basically in my mind xs has done the job of finding a good size single turbo and finding all the right parts to put it together. xs power told me in comparison to the greddy t78 thier turbo spools up faster but the t78 when well tuned can pprovide you with more hp. lets not for get that the people on this thread is looking for a fast spooling streetable car (whatever your definition is). i know i don't want to attain mor than 400 rwhp at this time and i am not looking for a fast and the furious 10 second car, but i wouldn't mind if at any point that i want to be able to upgrade from my current point (if i had the xs kit) i could then do so. this is the only reason that i would go with the xs kit (your choice e or s). i am going with the t04s because of the difference in price in relationship to the hp. and the only reason that i would run n2o would be if i found the turbo to be lagging considerably. luigi

LongRX7

iTrader: (12)

So where are you getting yours at and how much?

94touring

Probably kind of late now, but I forgot to say that he wasn't getting good traction. He had put on some 3piece niche wheels that weighed about 26lbs and had some crappy tires. On one run he almost put the car in the wall when he threw it into second, the *** end nearly swung all the way around. With some nitto 555s or mickey thompsons or something along that line he would be in the low 11's. Give me a month to put my engine back together and break it in, and I will post my 1/4 times and we will see if this turbo is crap or not. I will also be doing some experiemental water injection to see if it will raise the effenciency of my setup. It will be done at the dyno so we will see what the effects are, or if it does nothing.

Regarding if the apex kit is rebuildable or not:

It is not rebuildable, however it can take more abuse than other non ball bearing turbos. There is always some sort of trade off, there needs to be a turbo that spools up like the apex and still produces top end like the t88.

LUV94RX7

iTrader: (3)

Dave at KDR will be installing my Aquamist 2s kit in the next few weeks. Let me know how your water injection goes, I'll let you know about mine.
I will have a 4 gallon fuel cell in the back with a methanol/water mixture.

Ken

94touring

Great, let me know how it works for you and I will share my info as well. What turbo are you running? What has Dave said that the water injection may do for your setup? I am curious to see what effects it has on different turbo applications, so we will have to compare.

Cheuk in Seoul

O.K.

I guess I need to get in on this.

I have a ported engine from Japan and am using the US version of the RX6 turbo. The Japanese version actually has a larger Compressor.

My other mods are Haltech E6K tuned by Matt "Hitman", 1200 cc secondaries, Denso fuel pump, midpipe, catback, underdrive pulley.

I dynoed at 417 Corrected RWHP on a Dynojet and 443 Uncorrected at 15 psi. The turbo comes on STRONG in the mid range.. actually makes more power than ANY FD dyno graph I have seen upto 5000 rpms at 15 psi. Although it starts to trail off at the upper rpms compaired to a big T04 or T78, mine makes power all the way to 8000 rpms with no drop off in power.

Oh by the way these numbers were on 89 octane fuel.

The APEXi RX6 turbo has good potential and I believe it is a great street setup. It is perfect for my needs because I drive the car everyday and race once a month and have to deal with the poor quality fuel here... can't really use more boost... so I really can't take advantage of the high flow of the larger T04s or T78's.

Cheuk

94touring

Cheuk,
Thanks for jumping in with some info about the turbo. I was wondering if you would let me borrow the map you are using for the haltech so I can compare it with what I have. My email address is dans300@juno.com, thanks.

spyfish007

Cheuk: I looked up your old post in the single turbo survey. You stated you had a 1.15 AR turbine housing. I really don't think this is the same turbo . . . ? I have a physical copy of the graph and it just drops off at 6.5k rpm. Ari specially told me it had a really small turbine housing and the dyno I have would support that. If you say you have the dyno sheet, then I don't know what gives?!? (I am not trying to call you a lier either . . . )

Cheuk in Seoul

I only read the a/r housing off of the APEXi catalog... I doesn't look like a 1.15 but that is what they say.

I posted my dyno graph on the older forum.
I have a copy I can send you if you by email if you would like.
It is only in kph because the rpm pickup wasn't working that well but the graph ends when it hits the rev limiter at 8000 rpms.
The torque probably drops off at 6500 rpms but it is has a relatively flat hp curve from 6000 to 8000 rpms.

Cheuk

spyfish007

Here is a copy of Cheuk's dyno sheet . . .