Rpeck

Okay here is the scoop; I had a Hybrid turbo built from a builder that used to advertise on this forum. It was a “stage 3” T04 Hybrid with a 15 Deg clip. Well I was never satisfied from day 1, the lag was insane for as small as that turbo was, and I was not hitting any positive boost till past 4.5K rpm’s. I was maxing out on boost (or RPM’s) at only ~10PSI.

So I talked to a local builder (Bell Turbo) here in town, really nice old man that has been in the business for years, but deals in mostly diesel turbo’s. I removed my turbo this weekend, and took it in to him, he said he has no problems doing the work, but he is not sure what the best setup for a rotary application is. Well, nor am I, that’s why I am asking. With the current housing configuration what should I be looking for as far as the turbine wheels are concerned? Bell said that he thinks the 15 Deg. Clip is the cause of most of my lag, we are going to start by replacing the exhaust wheel entirely.. But he asked me to get suggestions on what will work well with this setup.

I greatly appreciate any advice I can get in this.

Mods are listed below;
88TII

Thank You,

Robert

Rpeck

If no one has any particular advice can anyone at least direct me to a web page, or a company that would have some knowlege on building hybrids for RX7's.

Thanks,

-Robert

felix_is_alive

well i used once on my rx a 60-1 from turbonetics .i had a p-trim with an a/r of .84 i believe tangiental housing. car ran great ,great response ,felt strong,once i elevated the boost to 20 psi ,got an .96 turbine housing ,got slightly more lag(barely ), but the car was wicked .
really great turbo for the street ,plus you can make a lot of power out of that setup

Rpeck

Thanks for the reply. What RPM's did your boost start to kick in at? do you recall?

$150FC

he's asking for a hybrid, not a full single. So he needs a turbine wheel that will fit in his stock s4 or s5 exhaust housing.

unfortunately there aren't going to be many options. if you were this unsatisfied by your stage iii i would probably go 'real single'. you already have almost half a turbo, you have your 60-1 and t04b housing, get him to build the rest of a full t04 with, just like felix said, a p trim and a .84 or .96 a/r. Then you've got to get a manifold/downpipe/wastegate, though.

since it's obvious who you got this turbo from, i'll ask you: did you ever talk to him about it?

Rpeck

I talked with him initially when I first got everything up and running. I purchased the turbo long before I installed it, my rebuild and all my mods took longer than expected. His consensus and some other people’s consensus was that I had a boost leak, or a WG problem, or something along those lines. I spent literally MONTHS searching for this phantom problem; I practically rebuilt the whole car again. Nothing came up. After much more research and quite a few phone conversations with other turbo people I came to the consensus that it was nothing more than a problem with the turbo itself. At this point I am sure the turbo is out of warranty, though it has less than 2600 miles on it, and I have no plans to ship it halfway across the country and wait a month to get it back. I am not here to bicker about money/warranty or anything of the likes, I made a mistake I will deal with it, I am willing to do and pay whatever it takes my local builder to get it right I just want it working.

Here is link that describes a lot of what was going on, and what has been done if you are interested.

https://www.rx7club.com/showthread.p...hreadid=234837

felix_is_alive

sorry about that ,regardless $150fc is right ,bye the way good call on the p-trim real good for street

VOLK YOU!!

why would u want to use a hybrid T04 with only 10 psi?

anytime u want a T04 is when u want to push starting at 12psi.

I have never tried clipped turbos, i always thought that messing with the turbine wheel is a very delicate matter.
Anyway anytime u clip a turbo, its supposed to increase spool time...slightly by allowing the exhaust gases to flow out quicker. So that means clipping it makes the turbo to lag more.

i heard guys clipping 5-8cm but 15??????

i'll get back to you on the right set up of fc's, been wanting to research on one.....

Maxthe7man

R-peck, I think you would be much happier with just a stock s5 exhaustwheel in there, with your hybrid , with the wheel unclipped, you should be able to make 250-275 rwhp... I recall who rebuilt your turbo the first time, and I think there thinking was that the clip job would increase flow and overcome the bottleneck of the stock exhuast side of the turbo, which it did, but ruined the impact design of the turbine blades, although it sounds like you already know that. All it does is make the turbo peaky..
12psi is a good number for a hybrid, it is not very effective over 12 psi, with the limit being about 15 psi, till the backpressure starts to make the power curve dip
If youhave the 60-1 front wheel and housing, with the stock s5 rear turbine, that should make a good combo, then if you want to push it a bit more, get a FMIC..Max

Rpeck

Cause I have the stock top mount at the moment. I will up it if/when possible once i put my spearco in.


I am thinking about a Turbonetics stage 3 turbine, or an O trim at the moment, 0 clip. My local builder will be taking my turbo apart on Monday or Tuesday right after the holiday .. then he will give me a call and let me know what he can safely fit in. The wastgate is ported very large for a married setup, it even has a larger cover on it.

I want a little more performance than the stock turnbine, I would like to eventually get into the 325Ish hybrid range, I have the fuel, and the fuel control, i have the oil and cooling system, The only thing I will need to start upping the boost more is a FMIC. The is in the works .. I am getting one either way, once I get a turbo that works properly.

I am just not sure if the stock S5 turbine will be the most efficent way to push a T04 60-1 compressor side. Casue we all know it's about heat transfer and effiency.

-Robert

$150FC

edit: woops.

iluvrx7z

Any updates Robert?

Dan

Rpeck

Infact Bell called me yesterday. They took my turbo apart and he said:

The turbine wheel has to be replaced with a HT18 wheel (same wheel that is it it) unless I want to go with a different housing and bearing setup etc. He said without the clip on the turbine wheel that it should perform just fine and up to my desired stardards. The wheel is $210 through them. He also said the WG flapper, and WG design was **** poor, he is going to replace the whole wastegate setup with an adjustable arm, so I can make adjustments to the flapper itself. He said the way it is now, the door just kinda hangs there, and it has some play to it that cannot be taken out without redesigning it. He said that wastegate setup was "made with pliers, and some bending" he did not like it at all.

I should have it back early next week, and Installed by next weekend at the latest. I will keep you all posted on how it turns out.. but this guy really knows his ****, and the adjustable WG setup he is fabricating for me sounds really slick.

-Robert

iluvrx7z

How much is he running you to do the work, if you don't mind my asking, perhaps I should start looking into what I should do with mine

Dan

Rpeck

No I don't mind;

$210 for the wheel, and he said ~$150 in labor, that's with the redesign of the WG.

so, under $400.

But it's worth $4000.00 to me if it's right, know what I mean?



-Robert

Rpeck

The good news is when I told him to go ahead with the work, he said he would call me if he saw any problems with the rebuild that was done, or any of the internals... he never called, so I assume all that was just fine.




-Robert

iluvrx7z

If only I had $400 I'd definitely do it now, hopefully it all works well for you, I actually have a picture of my redesigned wastegate, didn't think it looked too bad but what the heck do I know about turbos.

Good luck with the work!!

Dan

Rpeck

Ya, my WG was redone durring the rebuild also .. and didn't look bad to me, but I know it did have some play in it, I just did not think it was enough to impact boost .. but Bell says it certainly is. The play was the flapper itself, not the rod, or spring or anything .. he just said that whole design is weak. He says with the 60-1 wheel, new WG design, and a non clipped turbine I should be in perfect shape. I sure hope so.

iluvrx7z

I hope so to Rob! Good luck with the project!!!

Dan

Maxthe7man

Thats the best setup so far for a hybrid, the s4 back end has to small a wastegate.. Ideally you should get a whole different turbo, hybrids are a compromise, if you want efficiency, get away from the hybrids all together...Max

setzep

What if you guys just fixed the leaky flapper? Maybe that would clear up some of your issues? Funny... I have the exact opposite problem with mine, too much boost!

Rpeck

The flapper leak is not nearly big enough to be the entire problem, I asked him about that. He said I could even leave the flapper "as is" if I didn't want to pay to make it right ... but I chose to have him fix it. Also the adjustability of it will be a nice adition.


The wastgate is ported rather large, and the two chambers are ported as large as they can go. I am going to stick with the hybrid for now, if I am still not happy with it after all this, then my bad.. and I will ditch the hybrid all together. Just the cost increase is substantial going full T04. Manifold, FMIC, even larger injectors, external WG, Stand alone EMS, The turbo itself, New DP, Etc thats like $5k. I just want to make ~350HP, this should be close to getting me there, I am not looking for a non streetable 600 RWHP, no amount of power is worth a **** if you can't get it to the tires safely. I am driving 225/45 street tires here. Plus I have to pass smog every 2 years, with a hybrid, I can bolt up my stock exhaust system, put on my stock air box, put in my smog ECU chip and be all good. the more I change the more I have to deal with come smog time.

Right now my only future upgrade plans after this turbo is a Spearco FMIC, and a wide band O2. then i hope to be done with the car.


-Robert

Rpeck

oops.

setzep

Sounds like you have it planed out I just hope that after you get your front mount you don't get boost creep. A WBo2 meter is the best thing you can buy for a modded car, I love mine.

Rpeck

OMG, what a difference! Got my turbo back yesterday, put it in today ... like Day/Night instant boost in every gear ... it's like a whole nother car. I am happier than a pig in **** right now!

well off to play some more thx for all the advice fellas, boost on!!


-Robert