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Would an external wastegate be beneficial for my setup ??
So before i do my tuning I wanna do my last mods. Build sofar is 2013 r58 : 46mm billet k04 w/ turbosmart wastegate & upgraded divertvalve, ported cylinder head ( complete new valvetrain and cams & sneedspeed upgraded timing kit),catless dp & nvida resonated exhaust, ALL ic piping upgraded ( even plastic tmap pipe ) & alta intercooler , intake w/ 6in velocity stack , ngk plugs & dinan coils , nm module ( for now) and a .2mm thinner headgasket ( tad bump up in compression). Also has a stage 2x clutch and suspension mods to try and help...
I ALSO plan on doing a side feed billet intake manifold and after the intake manifold but befor i go with Lou for a custom tune i want your guys opinion on external wastegate and my setup. I'm aiming for 25psi as of right now it makes 21-23 depending on the weather.
please chime in and educate me , show me your setups too please..
Happy holidays, stay safe N motor on guys !!!!!
Last edited by MiniManAdam; Dec 12, 2025 at 07:04 PM.
Anyone yet ? I'd still like to do this mod and run an external bov in my interior piping and run a block off plate on the turbo..
I'm running 26.5 psi now and the forge bov but i need to install a stiffer spring in it and I wonder if an external bov not only would sound better but possibly hold and build boost better ..
Or, were you thinking dump pipe out the hood, like all the street racers these days?
I'd like to run a bov like this in the pic and have it plumbed into the intercooler piping on the correct side if the intercooler. I know my turbo I'm running is over looked because its cheap but I'm telling you , this thing fking spools HARD and FAST. And I bet with a custom tune I can run 30psi easily wit it and my setup.
As of now , im hitting 26.5 psi and in certain temps/air I can hit almost 28psi. But average it's 26psi.
and I do plan on custom tune very soon and I do plan to target 30psi too..
and man , that HKS would sound sooooooo sexy.. because arnt they just boost activated basically? I ran on on my Suzuki cappuccino and it sounded sooooo nice. And then with the stock divertvalve actuator sensor I believe would have to be turned off via tune then and air /fueling/timing tables all adjusted accordingly ...I mean, there's GOTTA be a way to do this.
Way back, there were some BOV kits for the early N14 engines, but the DME would throw codes with it installed. Since you have the Forge kit, which gets vacuum from the vacuum pump to open, I bet you could install one of those and use the forge actuator for opening, then blank off the turbo valve. That blow off pipe could potentially fit into the turbo outlet tube….
Way back, there were some BOV kits for the early N14 engines, but the DME would throw codes with it installed. Since you have the Forge kit, which gets vacuum from the vacuum pump to open, I bet you could install one of those and use the forge actuator for opening, then blank off the turbo valve. That blow off pipe could potentially fit into the turbo outlet tube….
duuuuuuuude ! Your absolutabsolutely RIGHT !
I could order the hks kit , plumb it in and run the bov off my forge boost sensor thingy and run one of these blanking plates.
only thing i wonder is the forge is a 2x port and the hks is a 1x port.
Are you sure you are making 22-23lbs boost untuned? It will go into boost cut and limp mode, you must at least have some sort of base tune
I have an external wastegate on my R400TS turbo kit and the other R400 turbo kits I’ve had. Those turbos and manifolds are designed for the external wastegate, turbos like yours would need a lot of custom work to make an external wastegate work, and there isn’t really a point to it to be honest. I have people ask me this all the time, and I basically tell them you need to buy a 4k turbo kit to run an external wastegate
Are you sure you are making 22-23lbs boost untuned? It will go into boost cut and limp mode, you must at least have some sort of base tune
I have an external wastegate on my R400TS turbo kit and the other R400 turbo kits I’ve had. Those turbos and manifolds are designed for the external wastegate, turbos like yours would need a lot of custom work to make an external wastegate work, and there isn’t really a point to it to be honest. I have people ask me this all the time, and I basically tell them you need to buy a 4k turbo kit to run an external wastegate
100% positive.. I argued with a tuner about it too.. idk how its even making near that..
I'm running an electronic boost gauge off true boost from my intake manifold. Ive verified the gauge is accurate too..
lol price means nothing... if it makes power it makes power..
your manifold sure is far sexier than mine ! But my cylinder head WAS ported though. Still stock sized valves buy both intake and exhaust ports were enlarged.
Last edited by MiniManAdam; Apr 5, 2026 at 08:24 PM.
I would measure with a mechanical boost gauge, I feel like you are probably closer to 16psi roughly if your gauge is reading absolute pressure. There is no way a stock tuned ECU would ever be okay with that much boost, I’ve literally tried to spoof it and take control but the cars will still reduce power output, especially on N18.
I would measure with a mechanical boost gauge, I feel like you are probably closer to 16psi roughly if your gauge is reading absolute pressure. There is no way a stock tuned ECU would ever be okay with that much boost, I’ve literally tried to spoof it and take control but the cars will still reduce power output, especially on N18.
brother , wanna bet ??. I hooked up 3x gauges and one was mechanical, all read the same. I even read boost off ecu and it matched.. here's my boost reading WITHOUT my nm module and a few mods. I'm making 6psi more than then now. I hit 3rd gear for just a second there.. as I come into 4th by the time I'm at redline now , im making 26.5 in 4th and 5th
I would definitely bet it’s been tuned before or you are reading absolute pressure. I’d definitely be interested in seeing your data logs
Here's when I had FAR FAR less mods and still hit 21psi.
once I get new suspension I can make an updated new video.
amd like i said , my boost gauge is running off an intake manifold vacuum port brother. It's absolutely reading true boost / vacuum.
Send a log, I want to see your AFR compared to stock and other values
afr under boost is 12.5..
.how you expect me to send logs.. gonna send me a tuner ? I mean cmon **** .
my aem afr running running bung in downpipe too.
like I said, Ile send better video soon.
my afr is still the same though making much .ore power snd boost than inbthe video.
In the last two videos posted to this thread, I see max of ~20psi, and you’re running a bigger turbo and NM module… 20psi on a JCW seems about right for NM module.
In the last two videos posted to this thread, I see max of ~20psi, and you’re running a bigger turbo and NM module… 20psi on a JCW seems about right for NM module.
no , no nm module in those videos. No upgraded wastegate , intaje manifold or downpipe , also had bad valvestem seals and stock cylinder head in those videos..
my car is making much more psi than that now..
I was posting those as a point , my engine on 100% stock tune with no jb+ or nm module and half the modifications/upgrades it has now and was still making almost 22psi with JUST my upgraded turbo.
this is exactly why i made another thread though regarding this..
so if you guys would like to discuss my boost because I definitely would like to dive into that more , here's the tread..
Crap it deleted everything I said UGH
well that 21.7 psi was on my engine when it had FAR less modifications and no nm module or jb+ , it was 100% stock ecu..
if you guys wanna discuss my boost , id love to dive deeper into it , i have a thread actually about it because i too cant believe how much boost it makes..
this is also why I've been very hesitant to custom tune and just run the nm module. I won't say any names but my last r58 during tuning , the tuner COULD NOT tune it above 21psi , it JUST WOULD not hold it. It could peak abit higher but generally held at 20psi.
So I discussed my current build with a few tuners and neither was able to promise the same power/boost levels I'm running with my nm module, so that's why I haven't custom tuned it yet..
my engine runs solid , safe and FAST. As much as id love more powwr im very weary now that ille spend 800$ tuning ONLY to loose power. Like i said , i talked to a very reputable tuner about my situation right now and he too argued with me that i wasnt making even 20psi , then i sent him those videos and he changed his tune and said ok well i mean theres no wayyy your making 26psi ( well you just said i wasnt making 20psi even and i proved i was sooooo...) and then I sent pics hitting that 26.5psi and I would have still been willing to trying tuning through him BUT he ghosted me and never responded to my emails again.
lolol like wtf , people just can't admit they're wrong ,it's so crazy. They'll do or say anything other than " your right , I was wrong ".. the inflated egos on people are hilarious.
but anyway, if you guys wanna shootTHEshit about my boost , here's the thread.
lets try and keep this one on topic.
