denisonnd

Ok, so if I plumb it back it the way it was it should go back to normal right?

Hi all I recently took my a car to a track and noticed some unexpected boost issues SO -RB25DET + boltons inc turbo, external wastegate, plenum and more -Link 4g Extreme -Car was tuned 4 years ago, done 20000k, 10 track days or so -300KW -Boost 1.07 Bar -When I floor it on a 3rd boost spikes up to 1.2-1.3 and then dropps off to 0.65 or so -I originally had wastegate plumbed back into the exhaust, now I have it open I've checked peak boost with open wastegate on the street and it seemed fine but when I took it on a race track and car was properly loaded up (drifting) boost went higher My mechanics suggested that possibly could be a because car was tuned with wastegate plumbed into the exhaust and it has less pressure so it has a boost spike, boost comes back because link ECU would have some fail safe function to cut boost (or bring it to "safe" level once it a lot higher then it should Another posiblility boost curve needs to be checked What do you guys think?

Funny how someone started this topic on Skyline forum. It's something I've noticed before. You never see a rotary guys or skyline guys starting similar topic on V8 forum or BMW M3 forum. Maybe because they really enjoy what they have. So there is no need to tell others that they are wrong about something.

LOL bungy jumping is even more terrifying But is does not compare to a good car that feels like you expect it to This is a car forum not a scooter forum Nice troll attemt though Speaking of Korean cars, maybe 200kw feels scary in Korean car. It's beside the point, S15 feels like better quality car then BF Falcon. FG Falcon feels more like a modern car.

I own S15 silvia with rb25det. Before looking into Silvias and Skylines I was thinking to buy a XR6T. I drove 3 different Falcons and they yeah, they are impressive cars when you compare them to its competition. They are better then 2005 Commondore SS, Toyota Camry Sportivo and such. You can easily make 300kw+ with basic mods, injectors, intercooler, tune. Big sedan is better daily driver. My question is how many of you buy/build modified turbo car so you can commute to work and drive 20k a year? If everyone was using such cars as daily, average miliage on your Skylines would have been 300-400k in 2015. The main thing fun cars offer is fun and a different experience. So I drove 3 Falcons and a number of JDM cars before making a decision. What I found was. 1. Skyline or Silvia with less power feels faster and more exciting then a Falcon. Lighter cars with more aggresive power curve always feel faster. In the same way as 300kw xr6t will feel faster then 300kw V8 2. You need to really push Falcon to get some excitement. Skyline, Silvia or WRX feel exciting on half a throttle. 3. Handling...........Falcon is closer to Camry then to any real sports car. In the past I thought handling is not important unless you on a racetrack. That's until I expirienced what good handling is. It feels fantastic even at 50km/h. Yes, it takes some effort to make 250-300 kw in a JDM car. But such car feels terrifying compared to many much more powerfull cars. After driving modified JDM car I was dissapointed in e46 M3 and in some other cars. Main problem was level of excitement. It is just not same.

Ecu:Link 4g extreme Mods: Boltons to make 310 wheel kw inc, plenum, throttle body, fuel press reg. Basicaly everything you normally see on such set up, no short cuts I have tightened throttle cable a few weeks ago Changed throttle control sensor I have a noisy (ticking) idle control valve Can't think of any other relevant staff I wonder if idle control valve is starting to fail, I was told it will eventually fail since it is ticking

Hi My car started doing something lately. When I stop at a lights my idle is about 1200 rpm (normaly 900rpm) while vacuum is higher then normal 0.72 onstead of 0.68. If I tap accelerator pedal once idle and vacuum goes back to normal. The confusing thing is why would vacuum increase when it suppose to decrease? Has anyone had similar thing happen? It that just a sticking accelerator pedal? RB25DET S2 Boltons 300kw Link G4 I also have noisy idle control valve if that tells you anything Car drives ok

Thanks Gts30t. I was excpeting this is the case

Tomei

Thanks for answers. It was not just the smell but liquid as well. So I assume diaphragm is leeting fuel through. Do you guys think I should a new reg? I'm worried it might lean out under boost

Hi everyone. If you take vacuum hose of fuel reg and smell petrol that's a fault fuel reg right? My question is will it only cause car running rich or will it also make car lean out under boost? Another thing, my fuel reg vac hose came off by itself. What can cause it

Well I had them on 20 to start of with, then I changed them to 1 and it became much softer and more comfortable. I have heard that the softest setting is not necessarily the softest, but it looks like it depends on many factors

It is a S15 Silvia with RB25DET and R33 gearbox. 8kg fr 6 kg r on softest setting. It has camber and toe arms and it doesn't have much camber. It holds up if I floor it from a rolling start on a motorway in 2nd, but it will lose traction on back roads or where tarmac is not as good

^^ Good point. I'm running BC BR on the softest setting and 265 T1R at back and it is still not enough. I'm getting stickier tires once these wear out. I like having BC's as I'm into drifting. But they are the reason I haven't tried a quarter mile yet. I know my 60 foot time is not going to be pretty unless I have NT05's and even then.

I've always felt that Evo/WRX STi with minor mods (exhaust+boost controller) feel like they accelerate harder then similar modded Skylines and Silvias. They also feel sharper around corners, but ultimately 4WD becomes boring as it feels too clinical. I also find it easier to have a relaxing drive in a skyline or even S15 then in an EVO. Now 300 KW turbo rwd + coilovers is a different story. My ass dyno goes off the scale when I drive car like that. It can properly scare you as you keep wondering if you will still have traction after a second or two. With minor suspension mods Skyline feels sharp enough around corners. + You can take your car to drift track days. I've never been in a 300kw Evo, but I believe it will feel faster in a straight line then 300kw Skyline. Shorter gear ratios, more traction, more off/on boost feel. I doubt it will be as exciting for as long though. Bottom line. If I want results in drag/time attack (I'm assuming you are not racing on the road) I'd go EVO and save for clutches and gearboxes. If I want to have more exciting and overall more pleasant drive I'd get a Skyline and save for tyres I believe that butt dyno and smiles/km is a big factor when it comes to tuned turbo cars. We are in it for fun and death defying / edge of space experiences (on a track hopefully). So yeah, I guess it depends what is more fun for you

It depends on a track use. When drifting there is always a straight where you can take a quick glance at temps You can look at temps and warnings. You can't look at Boost, Fuel press, EGT, AFR and Oil press on a track because they keep moving every second. AFR should have some fail safe set up or connected to the ECU. . Data logger is more advanced set up for track only car.

I was in your shoes before, here is what I found. Go for Defi or Apexi EL2 if you want high quality gauges with adjustable warning/peak recall/replay functions. Apex EL2 is cheaper but some Defi models have audio warning as well as flashing LED warning. Apexi has flashing LED warning. Another option is a data logger. Good example is Zeitronix. Basically you set warnings on your control unit and if any parameter is exceeded you'll see a flashing light that you can place anywhere on a dash. That system was cheaper then other data logging units and should cost you as much as a set of quality gauges. Here's my thoughts on gauges. 1. Boost/vacuum gauge. Definitely need one. Shows you how turbo is performing. Helps to spot boost leaks, boost creep, low engine compression. 2. Oil temp. It takes much longer for the oil to get to the operating temp then for the water. Usually 15-18 mins. Oil temp is better indicator of when the engine is warm enough for hard use. Also when oil temps exceed 110C it is probably time to slow down as 40 weight oil is starting to lose its qualities past this temp. Don't forget it is 110C sump temp, it is much higher at the bearing. If you are missing 1 liter of oil your temps will be higher then normal, while your oil pressure will be almost the same. It is important to look at your oil and water temps because overheated engines are more likely to detonate. So oil temp tells when it is safe to boost it and when it is time to slow down. 3. Water temp. Your stock water temp shows cold/normal/overheat. Most people I met at the track pay attention to Water temp. If you overheat your cooling system you may start blowing hoses and loosing coolant. You may have bubbles in the system and suddenly push coolant. Typically people slow down once it goes past 105C on a basic set up. Your stock gauge is still at a "normal" position and is hard to see anyway. Most people I know that go on a track pay close attention to Water Temp and Oil Temp gauges. 4. Wideband AFR. When your pump failed your AFR was lean and then your engine was gone. You can try "Fail Safe" AFR gauge from AEM if you don't have Link G4 or similar. If you are running aftermarket computer that has adjustable warnings (tables) like Link 4G this is a very good gauge to save your engine next time you fuel pump goes. If you connect this gauge to Link and set some parameters for example IF THROTTLE IS AT WOT and RPM IS >4000 and AFR is > 12.4 = IGNITION CUT (I think it switches rev limiter on in real life) I think this is better then fuel pressure at a regulator since it will cover more potentially risky situations where you can lean out and blow your engine. Injector problems, wastegate hose problems etc. You can also spot potential boost/vacuum leaks with AFR when it goes rich. Unfortunately you can not have AFR gauge with flashing warning light. It is just the way they work. 5. Oil press. I agree with posts above. It is hard to justify when you have oil temp. The only real use is you can guess when it is time to change the oil. Remember when you track your car oil degrades much faster then usual 5000km road use. 6. EGT. Most tuners I've spoken to don't recommend it. High and low readings can mean anything sometimes. You can be leaning out and still have normal EGT. 7. Fuel press. I still prefer AFR. But if you don't run aftermarket ECU like Link 4G. You better put this gauge (or AFR gauge) where you can see it. Pumps usually fail fast. So I think either go with good racing data logger system. I think Zeitronix is one of the affordable systems or get Boost, Water temp, Oil temp and some wideband AFR set up either connected to the ECU or stand alone Fail Safe AEM gauge.

I haven't used knocklink. I have heard it is not 100% accurate. One of the options is to use tables in your Link G4. You can get wideband sensor and AFR gauge, such as AEM with 0-5v input. Connect it to Link and give it some parameters. Something like (If RPM is above 4000, throttle at WOT or above 80% and AFR is more then 12.2 ==== boost cut). That will not help you if you experiencing knock because of bad batch of fuel but if you have a safe tune then it's probably OK.

Ok thanks. I know sometimes turbo will work extra hard to reach its set boost when there is a small leak. Can you have a situation where a car can reach its max boost and still have richer then normal afr at WOT(more black smoke) In other words would you benefit from a wideband gauge in this case or it will simply show up as lower max boost on a boost gauge? I have MAP sensor and take boost reading straight from the intake manifold if that helps.

I was searching internet for information on boost leaks . When people talk about how to tell if you have vacuum/boost leak they always mention rich or lean AFR's, boost leak tests. I always thought the easiest way to telll that you might have a boost leak from lower then usual vacuum reading on a boost gauge. Can you have a boost leak and normal (-20 /-0.67) vacuum reading at idle? It doesn't make sense to me

I wonder if R32 engine bay is smaller then R33's. I have S2 RB25DET in S15 Silvia. I have aftermarket radiator, no heat wrap or anything like that. Water temp stays at 88C-90C most of the time. I haven't bled the system yet. But I think it also has something to do with engine bay. R31 guys seem to ger lower temps then R32 with similar set ups I believe. My plan is to bleed the system, get exhaust wrap and change thermortat (in case it doesn't fully open). Would you expect higher water temps out of RB25 in a S Chassis? What do you guys think?

The water temp was fine. It was just a normal drive except I went to red line on 2nd and 3rd once. Now I remember there was some coolant on the ground under overflow bottle and some under the engine (should have told you that before). Overflow bottle is almost empty now. I just hope it is not lifting the head because of detonation or anything like that. The car has aftermarket radiator, but no oil cooler.

I just found it is a odd that car lost so much coolant one day and nothing after that Someone told me it could be the head gasket, but there is no oil in water. I'll take it somewhere to check the cooling system

Hi Last week I went for a short drive and floored it couple of times on high boost setting. The next day I found coolant under my car. I did not see where it came from. I added about 1.5 liters of coolant mixture and went for a drive without revving over 4K and on a lower boost setting. I haven't lost any coolant after 100km of driving. Do you guys know what the problem could be? S2 RB25 ,bolt ons, Link, 300RWKW, standard internals including head gasket. Cheers

I like RWD better