Turbo with kick? Recommendation for build EJ20 spec c

[TuneboyR]

Hi,
im running a stock JDM Ej207 Version 10 Spec C engine (W20C) in my hatch right now. Revs to 8k and making approximate 360whp (remapped) at 23PSI (VF49) and OEM Twinscoll.
The engine is beeing build right now with Mahle pistons, rods, hardened crank, 14mm headstuds, 2.0L.
So im unsure of which turbo i should choose. Im pretty much settled on the Rotated Kit from ETS since i dont have manufacturing skills and i like the intercompability with rotated and their FMIC.
Beeing the Spec C Engine, i have the big bore heads with non tgv manifold so i can rev to 8000 easily which should help. Also im based in Germany which means no E85, but 100octane fuel is widely available which should be ion between your guys 93 and E85 i guess.


So the car is 95% Daily Driven and 5% Track. So its only for fun. What i am looking for is a big turbokick. I dont mind if it spools a bit later. Thats why i dont want a EFR, they drive too "good", more like N/A. I am trying to achieve a passenger scare
From how i understood it, its the way the torque builds. If its pretty rapid / non-linear, its more a kick in the back then if its a linear buildup liek you have in modern turbo cars.
The Powergoal is 500whp ish.

So yeah, do you guys have any ideas? I was thinking GTX35 II but yea i have basically no clue.

Thanks!

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[Dave D.]

Originally Posted by TuneboyR

So the car is 95% Daily Driven and 5% Track. So its only for fun. What i am looking for is a big turbokick. I dont mind if it spools a bit later. Thats why i dont want a EFR, they drive too "good", more like N/A. I am trying to achieve a passenger scare
From how i understood it, its the way the torque builds. If its pretty rapid / non-linear, its more a kick in the back then if its a linear buildup liek you have in modern turbo cars.
The Powergoal is 500whp ish.

From my own experience (and opinion based on such), the best "kick in the back" comes from torque down low combined with the hp on top. I run a Dom 1.5xtr which isn't the hugest turbo, nor would it fit on your setup, just an example to consider specs.

My car has surprised experienced drivers whom I have allowed behind the wheel, and I'm sure it would thoroughly scare most passengers. With 100 octane you should be able to get some timing down low to generate good tq. On my dyno chart you can see that the tq does not come on gradually -- it's right there. 2.5 built block on e-85 with very free breathing intake and exhaust. very strong pull through 7k rpm; with your motor and heads I'm sure it would whiz right through 8k.

[K3rm1tth3fr0g]

^ OP remember that Dave's car above is 450WHP+ on most dynos. InFront's Mainline reads very low. ^ I second the Dom 1.5 being a great choice for awesome spool with buckets of power for the street. I run a 20GXT-R, generously given to me by dave , which uses the same size turbine as the Dom 1.5 with a smaller compressor. Great turbo. Neither will make 500 though - but if you've never driven a 500WHP car, you'd be surprised how crazy a Dom 1.5 can be... Though it really likes ethanol to shine. It does come in twin scroll though

First step is talk to Subi Performance in Troisdorf, or whoever will be tuning the car. Your tuner should ideally be a good resource to engage with when picking a turbo.

You can't go wrong with the GTX 3576 Gen 2, though it is a bit big on a 2.5L, especially for a pump gas car that sees track time - and you don't want to go big turbo, small A/R with a high revving motor... But for 500WHP without ethanol it is a decent choice. I don't love the GTX 3076 gen 2 but it is an option as well, but it will be harder to hit your goal. The 3071 makes more sense IMO if you are going GTX30 based.

Odd that ETS doesn't offer this on their site, but in terms of G series, the G30-770 is what I'd suggest for that goal. The turbo absolutely rips. '

GT35 power with GT30 spool and response.

[TuneboyR]

Thanks for the answers guys. Much appreciated.
Dave, my car as of right now also suprises people. It feels faster then it is

Kermit, the engine was beeing build by Subi Performance. I dont have a tuner yet, hence i thought i ask here. Lots of knowledge. Actually im running a 2.0L !
Since i cant get E85, i wanted to get a slightly bigger turbo and go for rotated so that i have power even at high revs. The VF49 drops at 6500 and at 7500 its basically 100hp less then at 6500 so no use at all to "have" those revs available

Also i was thinking maybe to go UEL Headers - i love the rumble. But yea, would lose some hp there as well so might the also get the bigger turbo for compesation (Although im still thinking if i should just get the ETS header as well, or the P&L Header which is a work of art. Not sure yet).

I could get the ETS Kit with vband piping but without turbo and buy the G30-770 elsewhere.

I never heard of Garrett G series. Why is it so good?

[TuneboyR]

-delete-

[K3rm1tth3fr0g]

I thought Subi Performance offers tuning?

Originally Posted by TuneboyR

Kermit, the engine was beeing build by Subi Performance. I dont have a tuner yet, hence i thought i ask here. Lots of knowledge. Actually im running a 2.0L !

Since i cant get E85, i wanted to get a slightly bigger turbo and go for rotated so that i have power even at high revs. The VF49 drops at 6500 and at 7500 its basically 100hp less then at 6500 so no use at all to "have" those revs available

Also i was thinking maybe to go UEL Headers - i love the rumble. But yea, would lose some hp there as well so might the also get the bigger turbo for compesation (Although im still thinking if i should just get the ETS header as well, or the P&L Header which is a work of art. Not sure yet).

I could get the ETS Kit with vband piping but without turbo and buy the G30-770 elsewhere.

I never heard of Garrett G series. Why is it so good?

G series is the latest turbo line from Garrett. It's the next improved iteration after the GTX Gen 2 turbos.

Skip UEL. If you are going this far with your setup and buying a new header, it is not worth the loss of transient response, along with midrange and topend power you lose by staying UEL. ELH all the way.

Killer B currently makes arguably the best header for most setups. The 'max flow' version is better above 600WHP but that isn't your use case. I've heard good things about the ETS header as well, but it seems a bit large to maintain good spool. I haven't heard much about P&L but it looks decent.

[TuneboyR]

I see. Well im afraid of that "modern" turbo spool. I drove my friends BMW M140i with 600hp and its fast AF but it doesnt have a turbo kick and it dont feel as quick / brutal. I really want to avoid that. With that new / modern piece of a turbo, i would think that it would just spool very quick / at low RPM and that the kick is getting lost.

I will check out the Killer B header, i didnt knew them so far. STI builds in germany are so rare - only rom tunes nowadays for DI Euros ;( So its very hard to get some knowledge.

I looked up the 1.5XT-R. With the twinscroll option it woul basically a plug and play turboswap without the need to get headers / DP (im running a 3" 200c DP for the twinscroll flange right now). I have to say that this is kinda appealing. It would save heaps of money. I could upgrade to rotated at a later stage. That 1.5XT-R is dropping at 6500 already though, i was hoping for a steady peak and hold for about 7500rpm. But yea, that one does seem to have a nice punch

[BlackFighter]

By the sound of it, you need to do a lot of reading and research before you start spending money. Read up on how turbos work and what you will use the car for.

[K3rm1tth3fr0g]

Lol. Trust me friend, making 500 WHP on a 2L does not come without some serious lag. No matter how good of a turbo you have. Twin scroll can help with spool but you will never make power like N/A.

You will still always have an S shaped torque curve.



This is in KW not HP but my point still stands. This is a G25-660 in red vs a GTX30706 in blue.

Look at dyno sheets for any 2.0L making 300+WHP and you will see the same S shaped curve. It can be mitigated, but never eliminated.

Look at the torque and HP curve on my current tune. I have a USDM EJ205 stock longblock with a Blouch 20G-XTR using a 10cm housing. The larger you go, the more this effect will be magnified.

[benflynn]

A g25-550 clone in that vf37 housing on e85 is a cheap 420hp

It will all in at 4k and I have seen at least [email protected], would crush the 20g above but it is big port and high CR, and my personal tuning ofcourse.

[K3rm1tth3fr0g]

Originally Posted by benflynn

A g25-550 clone in that vf37 housing on e85 is a cheap 420hp

It will all in at 4k and I have seen at least [email protected], would crush the 20g above but it is big port and high CR, and my personal tuning ofcourse.

Got a real dyno plot for that rip off turbo? The above dyno sheet and turbo are both real and have plots to compare against.

"398" on the virtual dyno doesn't mean much, no offense. That sheet is 400+ on Mustangs and Dynojets

I know tuners who have abandoned G series VF clones for projects after they performed so poorly.

[19std]

[/quote] ... 100octane fuel ... [/quote]

Man I wish we had 96 r+m octane gas at the pump...

[K3rm1tth3fr0g]

Originally Posted by 19std

Man I wish we had 96 r+m octane gas at the pump

We just have 105 octane E85

[TuneboyR]

Guys, wanted to keep you posted. I have the engine at home now, will pull the old one soon.
I still didnt decided on the turbo yet. But i wass starting to lean to a drop in turbo. Reason beeing it stealth, so that might help with police
I found a shop in the UK, owen developments. They have dropin turbos taht will bolt directly on my jdm twinscrollheaders and downpipe. Would safe alot of money.
My tuner recommended agaisnt the Dominator 1.5. He saw them explode on the dyno he told me.

[TuneboyR]

Guys, wanted to keep you posted. I have the engine at home now, will pull the old one soon.
I still didnt decided on the turbo yet. But i wass starting to lean to a drop in turbo. Reason beeing it stealth, so that might help with police
I found a shop in the UK, owen developments. They have dropin turbos taht will bolt directly on my jdm twinscrollheaders and downpipe. Would safe alot of money.
My tuner recommended agaisnt the Dominator 1.5. He saw them explode on the dyno he told me.

[K3rm1tth3fr0g]

Seeing a turbo explode on the dyno likely reflects more on the shops ability to install it correctly... Many omit the correct oil restrictor. Blouch uses Garrett CHRAs and balances their assemblies and wheels according to industry standards.

The dom 1.5 was designed SPECIFICALLY for the UK 207 market. It uses a smaller turbine than the 2.5XTR.

We need to know the specs of the turbo you are considering to provide any input.

My advice is still to slap a twins scroll dom 1.5 and send it.

[K3rm1tth3fr0g]

McDouble w/ cheese

[Dave D.]

Checked out a couple of EJ207 threads, maybe you've already seen them. The first one is a Dom 1.5 (7cm!) that runs low 11's. Second is a BB6466 T3/82 AR that runs mid-upper 10's.

https://forums.nasioc.com/forums/sho...ighlight=ej207

https://forums.nasioc.com/forums/sho...ighlight=ej207

[TuneboyR]

I have to say, the Dom 1.5 seems interesing. Curious if i should go for 7cm or 10, since i want to rev up to 8000 (maybe a tad lower like 7800), the jdm head revs to 8 from factory already.

Also i saw that there is a 3.0 XT-R Twinscoll Turbo.. What do you guys think about this one? I got a feeling that the 1.5 XT-R Twinscoll is kinda prefered

Thanks

[Dave D.]

Originally Posted by TuneboyR

I have to say, the Dom 1.5 seems interesing. Curious if i should go for 7cm or 10, since i want to rev up to 8000 (maybe a tad lower like 7800), the jdm head revs to 8 from factory already.

Also i saw that there is a 3.0 XT-R Twinscoll Turbo.. What do you guys think about this one? I got a feeling that the 1.5 XT-R Twinscoll is kinda prefered

Thanks

I'd definitely go with the 1.5xtr -- combined with the JDM-ratio tranny gear ratios I'd recommend the 10cm for your up-top fun, as you won't notice much difference down low. I have the JDM 6-speed in my car, so I can vouch for that.

I found it interesting that it takes a lot more of a build to pick up .6 seconds in the 1/4 -- and 34 psi. Probably not the best for longevity? In the street my 1.5 on ethanol has boosted as high as 27psi, usually max boost is about 26psi. It was a cold day and I could feel that extra 1 psi! 30psi is still fast as heck and much safer...

[K3rm1tth3fr0g]

So the twin scroll Dom turbos do not come with variable size hotsides. You get 2 x 5cm2 and that's it.

And there is a TON of nuance to single vs twin scroll...

If you want to change the hotside size you will be relegated to using single scroll. Which has much more support and upgrade options, but lacks the inherent response benefit of twin scroll.

I know you said OEM twin scroll but OP surely you can't still be on the OEM TS downpipe...?

Dancing the line of maintaining the twin scrolls performance, while also tapping into the engineering work of the aftermarket community is a tightrope walk. Twin scroll in a vacuum is a better design than single scroll, but how well or poorly the actual manifold, exhaust system, and turbo are designed and engineered plays a large role in how much better that design is, as does the specific engine configuarion.

For example, the Evo comes with a solid twin scroll manifold and everyone who makes turbos and headers for it primarily stays twin scroll because it's easy, and works well. For the WRX, most people don't have a cast iron twin scroll manifold they can slap a turbo onto to begin with, and those who do have the factory twin scroll manifold find out quickly that it is not the best flowing unit.

Most jump from twin to single scroll because of parts cost and availability, and because you can maintain the majority of the spool and response with single scroll. Not to mention are already buying a new set of headers, an up pipe, and down pipe when you are chasing performance anyway so it's not as if the majority of 400hp+ twin scroll guys are relying their factory twin scroll exhaust setup to save money.

FHI's OEM twin scroll setup is mediocre, and the housing is certainly limiting. The aftermarket stock location twin scroll options are mostly middling as well. Though RCM makes the best header for TS.

Flatirons Tuning did some good back to back testing with their Pikes Peak hill climb car and found the single scroll setups actually beat the twin scrolls in performance.

Everything except the MDX450 on this graph is twin scroll. The Dom 3 had trouble getting spooled up on the ej255 oddly enough even at 100% WGDC and after trying another Dom 3.



Also worth mentioning that ramp rate and spool is also determined by how the car is tuned. Telling your tuner to be conservative will result in a less hard hitting torque curve but will likely prolong the life of the engine.

If you are planning to go for more power, it's time to come to terms that the OEM exhaust setup has likely reached it's limit - your upgrade path from here is up to you. Single and twin scroll both have their benefits and drawbacks. You may be disappointed if you try to slap a Dom 1.5 on their and retune it as is. We don't know all of your mods as well and there is a lot to consider. If you have the money I suggest a rotated setup.

Based on you you mentioned rotated in your original post considering you are also contemplating rotating it, might as well go twin scroll correctly

Also rereading your post OP, you haven't driven a big enough EFR setup if it isn't scaring your passengers. Try a 7163... Hell my 20G 2.0L will scare the **** out of people.

Talk more with the shop who is tuning the car

[BlackFighter]

Though RCM makes the best header for TS.

Wow, had no idea RCM make aftermarket TS headers, they look very nice. But yha, if you want to stick/go with TS, it will be expansive and not much support.

[TuneboyR]

Evening.
Kermit, no, i am still on the OEM Twinscroll Downpipe. I am currently disasambling the engine, i am sure its the OEM one. I have a parts supplier and he said that the OEM TS Headers are pretty decent. Dont you think so?

I was mentioning rotating since its the "go to" solution at least in the states from what ive read, but i am starting to like the idea of a stock location turbo. Just because its pretty much stealth.
I am currently leaning towards the Dom 1.5 since i could slap that on the OEM TS Header and it would fit on my 3" Downpipe which is welded to fit the TS Turbo.

[K3rm1tth3fr0g]

Originally Posted by TuneboyR

Evening.
Kermit, no, i am still on the OEM Twinscroll Downpipe. I am currently disasambling the engine, i am sure its the OEM one. I have a parts supplier and he said that the OEM TS Headers are pretty decent. Dont you think so?

I was mentioning rotating since its the "go to" solution at least in the states from what ive read, but i am starting to like the idea of a stock location turbo. Just because its pretty much stealth.
I am currently leaning towards the Dom 1.5 since i could slap that on the OEM TS Header and it would fit on my 3" Downpipe which is welded to fit the TS Turbo.

No the OEM catted downpipes are terrible for flow.


You really shouldn't run anything larger than stock location on an OEM catted DP. Just throwing away performance.

[TuneboyR]

Sorry for the confusion. OEM Headers.
Downpipe is a 3" DP with a 400cp cat