Nah ................. surely you wouldn't do that ! :yelrotflm

Let's just say I don't hold it in high regard.

apparently somebody updated the thread tags: careful mods are watching ;)


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Team

The adaptronic might very well be a fantastic piece of tech. It's new, it's well supported, and it has whiz bang features. But I don't have $1500 in my budget. The used Int X was quite affordable, and my builder is knowledgeable with Int X. So that's what I'm using. This could go horribly, horribly wrong. I don't know.

And yes, before this goes further...I am aware that the words "budget" and "turbo build" should never be used together, but you play the hand you're dealt.

The inter x can be made to work ok (according to a few people I've talked to) . Where you lose out is that it doesn't cope with ambient temp fluctuations well and isn't so good on low speed around town cruising.

The three people I have spoken to who had it didn't mention any issues with temp fluctuations.:dunno:

My guy also mentioned getting involved with Mazdaedit of all things. Brett I know you are the master of that. To be honest, it's a bridge we will cross when we get there. The car arrived, and they will start work as soon as they have an open bay.

I have never tried it myself ..... that is just what I heard here on the forum :dunno:
I seem to remember Scott did some tweaks to the Inter-x to try resolve that so if anyone can sort it he can !

Low mount?
 

I have spoken to the builder, and to some members around here. We are discussing moving the turbo from top mount to low mount, for quicker spool up time. Unfortunately, it is some custom fabrication to move the down pipe, charge pipe, and some other stuff. It will be a day's worth of shop time, and the materials.

I know quicker spool is much more important than top end power, especially in my 4 port application. I would love some opinions from the turbo guys out there :bowdown:

In theory it is quicker, but how long does it really take that volume of air to move from the side ports 2 feet or so up to the top of the pipe.

At 3K rpm that's abour 130 CFM(before boost) or 2.1 CF/SEC of volume before it gets heated and have the fuel added to it. 2 feet of 3" pipe will hold about 0.098 cubic feet. So at wot it will take about 1/21st of a second longer to reach the turbo top mount.

I don't really know how it affects spoolup, but me thinks it doesn't on any humanly noticeable scale.

Great info, logalinipoo, thanks!

I'm no expert on it by any means at all, that's just my personal outlook on it.

It is so hard to compare the systems and really figure out how things will work better. You can try to look at different peoples systems, but there are so many differences that could affect spool up.

logalinipoo - great estimate

But we are also working with a gas that is compressible - i think once you factor that in plus reduced velocity of a gas thats compressed vs one that is not (close to exhaust vs after a series of bends) the difference will become a bit greater.

Unfortunately i am in the camp that believes a greddy kit is way better suited for your application - but the mazsport kit will work as well.

I don't think a day worth of labor is worth the benefit.

I was hinkingt when you first stomp on it It isn't building significant back pressure that's why i did it uncompressed.

Low mount = more bends and harder.
Top mount = smoother bends and lessor about equal bends.

Even with the pressure in the manifold 2 times intake at 14.7 PSI boost. You're looking at a 29.4 psi manifold or a compression factor of 3. multiply by 3 and that will put you about 1/3rd of a second. I think a 3" up pipe is dramatically oversized. I'm pretty sure the actual size is smaller and would reduce the spoo time from that 1/3rd of a second.

A Third of a second is signifigant, but you aren't building an all out race car or you would be using a different turbo and engine.

I bet a smaller turbo would help more and could cost less than a low mount manifold.

Thanks for weighing in, sause. Yea, the greddy kit is out there, but it just wasn't enough bang for my buck. There was also a lack of good used kits when I started the project. I had a very specific time table, because the car had to be ready for when I start up my second job, while my better half goes back to school. I had to either get it done before August 1, or wait till next May and try again. My impatience won out.

It is certainly not a race car. My entire thought process going into this is "faster than it was". Maybe that's flawed. ::dunno::

Thanks for the rough estimates. If this were a backyard project and I was just paying to have one piece made up, then maybe. But the total cost doesn't seem to line up with the benefits.

I have to disagree .
Top mount vs low mount (with same sized turbo) = significant difference in spoolup . I haven't tried to do any calcs on it.......... too many variables to even try IMO .
All I have to go on ( ;) ) is the experience that comes from driving several cars and seeing whats what all over the forums .

Brett

Glad you could weigh in. I have no doubt you have driven more cars than I. However, because there are so many variables, I feel like an apples to apples comparison is difficult. To the best of my knowledge, only Mazsport and Turblown offered kits both ways. Turblown doesn't seem to have a large install base, and there were several concerns about reliability and installation nightmares. (Yes, reliability of Int X has been brought up here several times, and no turbo install is truly plug and play).

I don't think anyone has done a side by side comparison of top mount vs low mount, because there are just too many factors. I believe HilamSteven here on the forum converted his Mazsport from top to bottom. I have shot him a PM.

All of that being said, Brett I am guessing that you believe it is worth the time and expense to make the kit low mount? I know there are concerns with my 67mm unit, and that low mounting should give it the best possible spool up that it is capable of? I also understand that the low mount has some side effects on the motor mounts and fitment

You could put a 61 a.r gt35 with a 60-1 billet wheel on the greddy manifold with no modification required (they come in t25) - that'll get you to where you want to be.

That's pretty much the bnr turbo with a billet wheel and a larger turbine if i remeber correctly...

I think it's easier (and cheaper) to go that route than to modify.

Either path you take, you'll be happy, i am sure.

Downside to a low mount is that you can't show off your snail when you pop your hood so there's that

Gt35 t25 housing: http://pages.ebay.com/motors/link/?nav=item.view&id=151705143351&alt=web

Billett 60-1 with extended fins:
http://pages.ebay.com/motors/link/?nav=item.view&id=131317617024&alt=web

Sause

Unfortunately I am financially committed to the Mazsport. I saw the upgraded greddy with the 60-1. Cool as hell.

Am I wrong to value the engine bling factor?

Lol not at all

In that case i would build as is and modify to low mount if you are unhappy with the result.

I think the best (and cheapest) way to get decent spool would be to sell the turbo you have and get a smaller one . It is going to be too much cost and pain to modify your existing .

(Absolutely no sarcasm or malice intended)

Same advice you gave me when I started this misadventure. Food for thought.

Thanks, Brett

Update time.

Car is on a lift and tear down has begun. Talked it over with Scott, and he explained that there were a lot of compromises with the top mount. Ecu relocation, OMP heat shield, wiring harness heat shield, battery relocation, and an extra five feet of piping. He said that his current kits are all low mount, for a good reason. Based on this, and a shorter install time, we have decided to go low mount.

good choice

Well ... I prefer low mount for all those reasons (plus the better spool up ) .
I just thought it would be a major operation ..... virtually everything has to change . Sounds like Scott can do it more easily than I imagined so ...all good !

His kits were designed to be modular. One manifold, one turbo, one intercooler. The other pipes were changed out (downpipe charge pipe etc). At one time, there was the goal of offering the pieces to change kits. Unfortunately, selling four kits (top mount, low mount, air to air intercooler, air to liquid intercooler variants) was just too complex. Some people did change kits, HalimSteven being one of them.

Scott has said he can fab up the missing pieces, and now we don't have to relocate half of the front accessories. I think that's a win win.

Good luck with the build, the car looks so well taken care of. Btw I have never seen a RX8 auto with no sunroof.