The only reason I dump on you is because of the sarcastic condescending tone of your posts . You even had something to the effect that you like getting under peoples skin in your sig. at one time. That kind of attitude doesn't sit well with me , so if that's how you want to play it , expect to get it back in spades .


Correct . And obviously there is a flaw in the design which I didn't see initially ( R&D is like that ) . Now that I do see the flaw and understand it ... I can correct it . Fitting a .83 would work but it's too big of a design compromise for me to consider it at this stage in the process.

There is no hole and I don't see your comments as trying to help when you present them the way you do. If I started again from here there is only one change I would make ... and that's the one I'm about to make.

Correct ... so what ? Talk to me again in a few weeks on that one.

Brett

Not to pile on, I know it can be very stressful when a project doesn't go as planned. Why did you dismiss the 3571/3576? Not enough top end power? I am not suggesting you change turbo at this point, I am just curious about the other option for those who aren't interested (or capable!) of following in your manifold creating, Siamese port waste gate building footsteps.

Thanks

And one minute you're dishing it out, and the next you're an emotional train wreck.

Now that we have the mutually opinionated yet irrelevant BS laundry aired out for everyone to see, why don't we just move on ...

The GTX3576r was definitely a good option . It was a toss up between that and the 3582 that I ended up with.
It all depends on your goals and where/how you want to mount it ..... wouldn't like to discount either of those you mentioned without knowing that.

The reason why is stated in Post #1

Low mount. I have been told I can boot anything up, provided it is T3, and 3" compressor inlet 2" outlet. I am always looking at the next step, which is sad considering I don't even have the first turbo complete.

Once you have fully come to grips with what you have , you will have a clearer picture of where you want to be ..... then we can talk :)

Looking forward to it. Best of luck with your build. If anyone can make it work, it's Brettspeed

This is how I plan to dramatically improve spoolup :

By joining the Siamese port to the front rotor tube .... this should happen at spoolup .


https://cimg5.ibsrv.net/gimg/www.rx8...b68c65a7b4.jpg



So more than double the energy through the front runner + slightly less energy through the rear runner = huge improvement in spoolup.

Once the wastegate opens fully all the siamese pulses will disappear.

I think you will have some reverse flow after the WG opened, and still a slight imbalance. May not matter much but be very aware during tuning that the housings are under different conditions.

This has been posted before but iirc it was a different setup. If you could fit this in between the manifold and turbo it could be cheaper than modifying the exhaust manifold...

http://ep.yimg.com/ca/I/supra_2267_345948851

This then puts the flow from both rotors to one side of the twin scroll to spool and opens up as boost increases. I think you were against this idea though iirc... Never mind me. Just another BS post... :lol:

Quickspool valve won't work with a divided manifold, it would just block one of the housings. For a conventional bottom mount with enough room or a top mount it would.

How silly of me :lol: I forgot that little detail...you could remove the centre divider there though, that would have the desired effect.

EDIT,

like this,

http://www.homemadeturbo.com/attachm...alve-qsv10.jpg

We can get a really nice entry into the tube ..... so any reverse flow will be minimal . But yes , I am aware that there will be a small difference there . This will make retaining the A/R1.01 even more important now.

There may also be a negative impact on wastegate efficiency. But it is so good now , i doubt it will make any difference .

Interesting that you should post that . I'm thinking the effect I will get will actually combine some of the benefits of a quick spool valve with a twin scroll . So it will actually do better than if i had managed to get full division of front and rear rotors by virtue of the fact that the interference between the pulses from the rear rotor is non existent. Plus the velocity through the front rotor tube is very high and practically constant .

it should have a similar effect, I was thinking it would be cheaper and easier than modifying the manifold to get where you want to be. You could keep the wastegate where it is because you know it operates as you want, you proved that one. you'd still have the issue of the volume of the centre though. So really, the manifold modification to your centre pipe would kill 2 birds with one stone, so it's all good. :)

I think you missed the problem with the existing design ......... which is that the siamese pulse enegy is completely wiped out as it hits a dead end . The only way to address that is to modify the manifold.

yup, realised that when you edited your post :wiggle:

it should be alot better, and if you're keeping the wastegate on the centre ports it should stay very controllable. :naughty:

Just want to address this for the sake of discussion .
Pre turbo AI was only a minor consideration so don't think that was what my decision was based on . It's just something I've read a lot about and thought it might be an interesting thing to try.
Going to the cast wheel was all about the top end efficiency (at my target boost ) of the GTX3576 vs the GT3582 . You posted the maps earlier so I'm sure you are fully aware of the difference.

Eta?

I'm aware of them. Also that they can't lay out the whole picture either. Maybe the ability to spool up was over-estimated. If so, then the statement regarding surge on the 3576 has to be revisited. Yes, the 3576 flow efficiency falls off a little sooner on the far left. However, and this is only a sincere opinion, you seem to be too focused on a peak number now rather than the larger picture represented by area under the curve, response, etc.

Agreed



Not at all .Easily reaching my peak goal was nice, as was the boost control aspect, but if only you knew how bitterly disappointed I was when I realised that the way it was spooling up was how it was going to be.

The reason I haven't done the video 9k asked for is that it isn't that impressive IMO. However ,how about waiting till this design change is done and tested before passing your final judgement over all my "poor choices" ?

Also ...............why won't you 'draw a line in the sand' over what you would consider a success in regards to spoolup ?

BTW I do realise that I set myself up for this kind of scrutiny by choosing such a provocative thread title .

Am waiting for him to give me a price tomorrow . But it is booked in this week anyway .... whatever the price................. LOL

Will also be getting a few other things addressed at the same time :
*Refitting my old polyurethane engine mount - he fitted his own design which I questioned at the time and have found wanting.
*Fitting a driveshaft loop - a requirement for certification of modified cars here .
*More heat shielding of the intake pipes as cruise AITs are higher than on my previous setup.

Why I didn't choose an EFR 8374 ???????
 

This keeps getting thrown back at me so I want to specifically address it .

If you were to ask "what is THE BEST turbo for quick spool and 4-500 whp for our engines " I would say without question, that the above turbo wins hands down . Even though no-one to date has even fitted one .
I looked at using it and decided against for a number of reasons that stemmed from the fact that I specifically wanted a low mount setup.

The main aim of the project was not only to make a system capable of 400whp but to also keep the engine happy while doing it (whilst getting Greddy like spoolup ) and thus create a viable alternative to an REW swap. To just slap on a big turbo has been tried before on many occasions . How many 400+whp Renesis engines are out there surviving this on a daily basis ? None that I am aware of . So I felt the need to try something different, hence the siamese wastegate idea.
From the pics it is obvious that the turbo I chose is extremely cramped already so here are the size considerations that excluded the EFR :
It's very long
Both housings are large in diameter
It has a BOV and a WG actuator hanging off it
It uses the very large T4 flange
It has a 4" intake (we couldn't even get a 3" to fit let alone a 4")
Also:I have a steering column to contend with

As I have said before , if someone actually ever manages to fit one AND achieve what I set out to do here , I will be the first to congratulate them.

We know the 8374 would fit as a topmount so why wouldn't that be the "ultimate" ?
Maybe it would be in terms of spoolup and peak power and dare I say it ...bling .
But :
Will the engine last , will this turbo be any better at overcoming the Renesis weaknesses than any other big turbo ?
What is the compromise to to handling having all that weight up high ?
How long will everything last that is in close proximity to all that heat ?
What other compromises are made in getting all those hot pipes past the OMP,APV and ECU ?

Then again ..... maybe it wont have any better spoolup than what i'm doing.............................

You claimed to be throwing that out for discussion, but there can't be any discussion because you take every comment as personal criticism and get twisted out of shape.