Jump to content
SAU Community

Recommended Posts

Guys,

I have a rb20 running a 2535 running 14psi using a bleedvalve (yes I know, but my elec boost controller died recently...)

It makes full boost at 5k rpm

any idea's what could be the problem? Surely the 2535 cant be this laggy

Yes i did abit fo a search...

Cant find any boost leaks, found a few suspect connections and fixed them up, advanced the timing slightly.

Any help would be awesome, as its not very drivable :devil:

Cheers,

Dan :(

Edited by works 510
Link to comment
https://www.sau.com.au/forums/topic/213541-rb20-gt2535-not-responsive/
Share on other sites

Supporting mods.

gtr or 040 pump, i have to check it

3" exh with GKtech dump and hks front pipe, cat is std for now.

evo3 intercooler and home made piping

awaiting to install gtr injectors

blitz pod

Ill get a tune asap :devil:

Yep must be pinging its head off at 14psi and injectors are probably maxing out too

Get the GTR injectors installed and get it on a dyno - REMAP/PIGGYBACK/STANDALONE but either way you will see improvements

Put the boost down before you blow something :thumbsup:

tune isnt gonna bring the turbo on song any quicker... exhaust flow governs how quickly ur turbo comes onto boost..

first thing u should look @ is exhaust flow properties. check ur cat, make sure nothings block and ur exhaust is as free flowing as possible.. check wastegate operation as thats what controls the speed of the turbine. if its opening a lil too early and slow enough, it will make ur turbo laggier than it should be. spring tension is something to check for on the gate.

2ndly cams with more duration and lift will bring the turbo onto song quicker, but ull need supporting mods.

If its an aftermarket manifold, wrap it up. heat = energy. the more heat u can keep inside the exhaust the more energy will be exerted to the turbine wheel at a higher velocity hence reduce lag.

check ur intake for restriction.. try blowing through a kfc straw or sucking.. not very good for flow compared to something bigger like a maccas straw.

a tune will only make what u have a lil more drivable.. but it wont bring ur turbo on full song any quicker.

START WITH THE WASTEGATE SPRING TENSION FIRST

^^ Macca's straw FTW!

PS: Iv seen increased ignition timing changes raise fullboost point by 300rpm.

Dato 1600 FTW!!!

I spent my youth droooooling over 1600's...

thats all.... *cough*

A solenoid type boost controller made a world of difference for me. By the way, that much boost through that turbo WILL melt your pistons if you're only running stock injectors, please turn the boost down for now!

The hks2535 isn't the most responsive thing on a rb20...in fact...just about any turbo except for the stocker won't be responsive...i know because i've got a 2535 on a rb20...however...yours seems alot worse...

The guys here have basically covered all your bases...restrictions in your system would be first thing...and then after getting the proper support mods a tune will go a long way to improving driveability once you dial some timing in...if you cannot afford engine management and a tune now then suck it up and drive it the way it is...do not run at at 14psi...turn it down to 10psi and run it till you can afford it...mind you it will run like a POS till then...

HKS turbos usually come with an adjustable actuator which you could possibly shorten to bring on slightly better response...mind you max boost will also rise so be careful...and when the time comes for the tune...running higher max boost will also improve boost resposne down low...i have attached my dyno graph from my recent tune...it should give you an idea of what boost response vs rpm you should be expecting...thats at 19psi though so boost response is abit better but its still gutless down low...

post-24077-1207442258_thumb.jpg

Thank for the help guys :yes:

Ill turn the boost down for now and have a look at the actuator.

As for restrictions in the exh, the only one I have is a stock cat (been gutted tho)and funds are minimal at the moment

The rest of the system is either brand new (catback was made a few weeks ago) or in good nick.

I had a play with the timing last nite, didnt really bring the boost on earlier, but it seemed to gain abit of power

Intercooler piping? Its not the best and long, could this make it worse?

Sorry for the questions, ive been playing with weber powered nissans all of my life :thumbsup:

it will be the hks actuator not setup right

I think there was one with the kit softy bought off me

they need yeaps of pre load to get them setup right

setup soft they will still run 14psi just very late in the rpm like what your getting dont expect much under 3,500rpm even setup right though

you should be needing to use two hands to put the rod onto the clip

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...