does anyone have results for a 73HTA green with the SS housing? preferably on a 2 liter with mivec?

i thought i had finally settled on a JB green, but i then realized all the nice spool graphs were on an MHI 10.5 housing and not the ss single scroll.

turbo is going on a dedicated track car that needs to be able to run 25minute session and produce anywhere from 360whp to 400whp depending on class, but i of course need to maintain decent spool (no later than 4k).

 

Can't find any either, but its accepted that spool is later than mhi greens. Not by much, and its probably negligible on the road.

Since you're asking, I'll give you my opinion on the green. When I switched from stock to hta green, the first thing I noticed after tuning was the later spool (obviously). It is very evident when compared to stock. Yes the power increase was noticed, but my very first thought was..."I can't wait to build a 2.3 so I can get spool back and keep the power level." I miss the response of the stock turbo. If 4k is your cutoff the the green will likely sit right at that limit. Maybe a bit better with mivec.

I seem to remember you having a bbk? I might be confusing you with another member. Anyway, if I were to do it over again I'd get the 71hta chra. From what I gather, it nips at the heels of the green in peak power on pump gas and spools better. And you keep your turbine housing, and its cheap...although FP must have a sale going on because greens are going for damn cheap right now. I'd be tempted too. But if you're a spool junky like me, I was left unsatisfied with the green's responsiveness. Look into 71hta...there's lots of literature available here on its potential

 

I went with a Green DBB last season and haven't looked back.(not the SS housing)


It makes peak torque at 4000 vs 3600 (50ftlbs better) makes 400 wheel at 24psi on a conservative track tune.
On the track the later spool is nearly negligible. I think it might feel laggier only because the hit is harder.


At the Glen I have to drop to 3rd for 9 only for smoothness on exit. I have to shift to 5th between the toe and 8 where before I just held 4th.
It maintains constant boost all the way down the straight.


LRP is still all 4th and 5th.


Hope that helps some.

 

A guy just posted in another red with back to back comparison with a red on the same car, with 92 octane pump gas. The MHI housing had 20psi at 4k rpm, and the FP SS housing had 20psi at about 4,250. The green is historically about 500rpm faster into boost than the red, and I imagine the housing change should have a similar effect. So, I would guess you will see 20psi with the green and SS housing in the 3700-3800 range, and full boost at or before 4k, which would be perfectly fine for a road course car making 400whp.

 

nope, ive never had anything but the stock turbo. im well aware of the 71hta, and ive seen mixed results. but again, its tough to find results on stock cams and pump gas...the last thing i want to do is make two moves here.

unfortunately im really only interested in the ss housing, as a non stock housing is slightly appealing for the torture of track duty since you remove the fragility of the stock housing/volute issues.

have a link by any chance? if thats the case then yes, its probably acceptable but keep in mind im talking JB NOT BB. on my current imperfect self tune im on full boost just shy of 3600 so 4k is a big change. there may be a few tricks to get it slightly faster but i wouldnt think more than 100rpm earlier would be do able

then theres the blouch/ex-cbrd stuff...but BB was recommended for road course duty and i dont know that $2200 for a stock housing turbo is worth it, even tho the 1.0xt/bbk full has been pretty proven...

 

I wont buy an FP with stainless housing. I just dont care for it. Twin scroll for the win.

 

going from a stock turbo to HTA green on ss housing is going to loose 500-600rpm of usable low end. If I were you I would ask robert to build you a 68HTA with the ss housing. the 71HTA and 68 use exact same comp wheel. they just changed the name when they switched to the shrouded comp cover. you dont want a shrouded cover. you dont even want a 9 cover. you want a stock 8 cover cut for 68hta wheel. the 8 cover is important. will give the best low end tq. the hotside will consist of current green red blaclk hotside. including the big exhaust wheel. this would make a hella good autocross turbo on low octane pump gas.

 

So your saying take the 68mm compressor wheel from the 71hta and combine with the 58.8mm wheel from the green? Might be interesting, but what are the chances of something funky happening since it's an untested combo?

Doesn't the exhaust wheel have the most effect on spool? I'm not fully understanding how

 

One of my customers made big power on a SS green. I will be sharing the results soon here. Hope it helps someone else reach / meet their goal. I will not hide any of its mod list when I post the results.

As Jerry & letsgetthisdone mentioned, it does come with lag, since its no longer twin scroll of course.

 

we are fabricating an evo ix o2 housing/downpipe/dumb tube for the FP black SS housing

cb

 

its a well tested combo on early dsm platforms. I am sure robert will happily build you this turbo with no warning of poor outcome. you can have a compressor wheel thats too big for turbine wheel. but you can NEVER have a turbine thats too big for compressor wheel . the 6h turbine mated to 20g was a very, very good turbo for the dsm crowd. this turbo I speak of can only work better as the 68hta wheels smokes of 20g wheel in every respect.

it is important to use the 8 compressor cover. the 8 cover is well proven to spool faster than 9 cover. and 9 FAP cover spools even slower than a 9 cover.. the FAP cover will not be needed as the 6h exhaust side will not put the turbo in any surge trouble at all.

 

ill shoot fp en email. you have more experience on these cars than i do, and i am very rusty on my turbo tech.

i think i saw something like 200rpm increase in spool from the FAP cover, but do you have any data of the 8 vs 9 cover? just guessing but even on a 9 cover i would think this combo would definitely be spooling before 4k...

 

Interesting combo idea. Probably pretty close to what MHI would put together as a 'proper' sized option. Please post up what you hear from FP..

 

I never wound up getting a response. Meanwhile I put the car on e85 and stopped needing a turbo.