Hx35

[bomkamp6]

I have a chance to pick up a rebuilt hx35 for dirt cheep but is this turbo going to be crazy laggy? i been lookin for a hy but they are uncommon compared to the hx just wondering if i should do it or not

[Mazda_Powered]

Have you done a comparison on the two? They're not far off from being the same...

[Iantboyd]

If you get a twin scroll manifold that will help a bunch, are your pistons over sized as well? Head work, cams? I am thinking all these will help. It's not going to ever spool like a vj20 but for how large and capable they are it sounds like it wouldn't be bad. I have only found a handful of people who have yet to run these on a Bp.

[bomkamp6]

std bore 9:1 cp pistons exintake cam swap cut intake tubular mani and ill look into the divorced flange and any of u ever try using a spool valve?

[nerd racing]

I have one of these I have not had a chance to install it yet though. I am looking for a BP4W head to pair it with, along with head work.

[Mazda_Powered]

spool valve may help, you could also try bullseye's .70 a/r turbine housing...is not longer twin scroll and would spool a few hundred rpm sooner.

[bomkamp6]

yeah what rpm range will the hx start spooling? i was lookin into buildin my own spool valve only not using the spacer plate style but using the turbine its self it looks like it will have alot better flow when blocking and then i can also use a divorced manifold and get the most out of the twin scroll set up heres the link http://www.enginebasics.com/Advanced...ve%20Test.html

[Mazda_Powered]

Are you building a manifold for the twin scroll? Or are you just re-flanging something? Just trying to find out if it's going to be the proper firing order to even make use of it's design.

[Iantboyd]

spool valve may help, you could also try bullseye's .70 a/r turbine housing...is not longer twin scroll and would spool a few hundred rpm sooner.

Jack, the twin-scroll design decreases turbo lag and spool threshold. switching to an open style would make things worse, that is assuming a twin-scroll mani is used.

[atomicEGT]

spool valves are rad.

one of these days I need to get a video of my boost gauge and tach for all of the "Holsets are laggy" guys.

[Chad]

i wish i never sold my hx35... i would love to upgrade from my vf10

[Mazda_Powered]

Jack, the twin-scroll design decreases turbo lag and spool threshold. switching to an open style would make things worse, that is assuming a twin-scroll mani is used.

Oh I know, if he gets a proper twin scroll manifold made he'll be laughing...but if he just reflanges a Miata manifold it probably won't have the proper firing order in mind for the twin scroll design lol. Just giving him options for different routes.

[bomkamp6]

its been awhile since i posted on here had to hold off on the hx project for awhile started a few different projects lol but atomic what rpm does the hx start spoolin up for u? what manifold are u running and what spool valve are u running? i have herd good and bad about the valves. im just not sure what one i should run i guess the only down fall of the valve would be high back pressures while cruising because the valve will be shut just lookin for a little more input

[atomicEGT]

I have an HY, not an HX.

I think I have full boost at 4k? At that point I am too busy trying to keep the car in a straight line / not die to watch the tach/boost gauge. I think there's a video of the car in my build thread and you can kind of get an idea of the power delivery.

[bomkamp6]

well damn i thought u ran the hx what would u use if u had the hx qsv or build a nice twin scroll mani? ir i guess get that bullseye turbine houseing