Jump to content
SAU Community

Spooling a big turbo./ lots of grip

MJTru

By MJTru,
in Engines & Forced Induction

 Share

Recommended Posts

MJTru Mentor

MJTru

Posted
Posted

Well today I tried a new setup on one of my r32 gtr build I had done a while ago. When I say tried it. I mean race the car.

This car makes good power once I'm off.

It had tons of grip and I can't seem to get it going off the line even if I pin the gas to the floor at 8500 rpms. It's a built motor but uses a old gst72 turbo. It's a old turbo long with that being a journal bearing.

What I'm doing it comparing it to a smaller set I had on another one of my car. I trying to find out what could be the problem if not it being the turbo itself.

I'm guessing the turbo is a 72mm.

For now I know my breaking gearboxes

In 3rd with this car and until my os88 is delivered in have no choice but to use the 3 stock boxes to work things out. Oh

I have 2 r33 box that I'm going to be keeping for gear sets. Just to try out.

Anyways what's happening to the car is its bogging off the line no matter how hard I let it go in first gear. I guessing the grip is alot more than my other cars and it sitting on 4 275 tires nto1's. I'm guessing it's the turbo. Being a journal bearing and a old design. Or is it the cams as this car is my first car using cams. That's one concussion I can come up with, as to the difference between the 2 cars. One was full stock. And this one is built, but so much more lazy off the line. After I smashed 3rd gear I gave it my best to see what it would take to smash 1st and even second gear. But the car would just fall over on itself and bog off the line. It goes it just like my other gts4. I'm wondering what all could be my problem here.

What's the biggest turbo I can run until it would act this way. Is it because it's big and a journal bearing turbo. Is my cams affecting the tune down low and what could I look for/or do as evidence of this.

I'm stumped here. I'm sure I have no boost leaks, but worth checked. Is my turbo oversized. One solution is to use an anti lag device off the line, but it's so hard on the motor and the turbo.

 

Any suggestions would be appreciated guys.

 

Link to comment
https://www.sau.com.au/forums/topic/470066-spooling-a-big-turbo-lots-of-grip/
Share on other sites
MJTru Mentor

MJTru

Posted
  • Author
Posted

Yeah I'm stumped to. It has to be timing and fuel I was thinking the same thing. On launch I don't see to much black smoke indicating fuel. I'll also check the timing.
It has to if it's to advance I can see it not reaching peak cylinder pressure and killing my take off. Also to lean to be bad. But I don't feel it a lean problem. Best to start logging this week end. I need to buy to damn hub dynos.
Thanks for ideas guys

baron_von_bootsector Enthusiast

baron_von_bootsector

Posted
Posted

The turbo is a bit archaic but it could be that you just are not able to get enough load to get the turbo up on steam?

I completely agree with Allan on putting a built auto and transbrake into it - would make launches so much easier / consistent and will put a stop to your exploding gearbox dramas. Going with a more modern turbo and potentially changing cams / timing would likely help if you want to remain torque-converterless.

Anti-lag would help the situation but you are right it can be hard on the hot side depending on how you do it - what kind of ECU are you using?  

MJTru Mentor

MJTru

Posted
  • Author
Posted

Thanks guys. I have already paid for a OS88. So the power glide is out, but may be a solution for another build. After I slowed down and looked at things I'm not sure but I'm thinking it's timing because of the 272 cams in the motor. As it should rip the tires up like mentioned above. At 22psi and 8500 rpms it shouldn't fall flat on its face then go. It bogs all the way down to like 4k.

Then gradually climb up and as boost kicks in at 5500 pulls hard after that.

Between the motors only the cam is what's different. As the duration is way more. I'm thinking of what I'll need to do to get her going timing wise. As the cams are leaving valves open longer and a small bit more lift. I should slowly start to retard the timing whiles looking at my knock levels and making sure there is adequate fuel. Hmmmm cams are hks 272

 

Whats the cost for full power glide setup. ???

 

 

 

MJTru Mentor

MJTru

Posted
  • Author
Posted
8500rpm launch and its bogging is abit strange to me 
should be blazing tyres once ur off the clutch
sorry don't know what it could be

I have ever had this same motor/cam in another body and it was the same thing. Couldn't launch. I'm thinking it's the cams. Hks 272. I'm not sure of the lift. May be standard. But the added duration I feel may be my problem.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • RP1421
      S15 Spec R

      By RP1421 · Posted

      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. 
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      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.
    • perry_r33
      R34 GTR Vspec Garage Sale - All must go!

      By perry_r33 · Posted

      Pm sent 
    • Robot
      Skyline v36 350GT sedan hunting on idle

      By Robot · Posted

      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 🤣
    • GabsReDeal
      R32 GTS (RB20DE) Injectors Replacement

      By GabsReDeal · Posted

      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...