Jump to content
SAU Community

Poor Turbo Selection - Need Help Brainstorming

GTScotT

By GTScotT,
in Engines & Forced Induction

 Share

Recommended Posts

GTScotT Grand Master

GTScotT

Posted
  • Author
Posted

Cheers Disco, I do appreciate the newer car vibe. For myself I actually have an S14 and am nearly finished with the setup. The sigma is sort of a side project for me, mainly my brothers with some help from myself. Realistically if I dont participate nothing will ever get done.

Looking under the bonnet and seeing the manifold etc really does make me sympathetic to the old astron lol, a lot of time and effort has gone into this setup and it would be a shame to give up on it. The money to date is also a major factor for me to try harder. I wont say how much has been spent to date, but it is a lot.

Just to be clear would LSA need to be a higher or smaller number? I will put my feelers out for a factory cam, brother wont like that but it may get us somewhere. Ill also try to track down a larger housing for the GT30.

  • Replies 53
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Posted Images

jet_r31 Mentor

jet_r31

Posted
Posted (edited)

higher=less overlap

not sure how mnay cams you've changed in sohc motors disco..but that reaks of problems

with turbo cam 10+yrs ago..things have changed a lot since then and cam makers have cottoned on what a

engine needs a lot better...we aren't getting old blower grinds anymore with large overlap that blow all the energy out the ass end. I think all the problems you mentioned come back to to lsa actually..

I've had people sell me blower grinds that where shocking 10+yrs ago when asking for turbo cams, and yes all those

problems existed, but the grinds these days are alot different.

Even a basic stage one cam with a 114lsa would outperform a "standard" cam in every way usually, theres more to cams

than just duration and lift, the way the cam is designed in regards to the lobe shape has a big effect on drivability,

Even going back to sohc cam rb30's, the tighe cams are quick lift cams, they run much more lift and duration than stock..but still make more bottom end and midrange torque than the stock cam and spool a turbo quicker...and make another 30-40rwkw..lol

twin cam stuff is a different kettle of fish again, and the designs are much more recent..

personally if i only had the choice of one , i'll take duration over lift any day of the week with a turbo car..providing i can change the LSA

cheers

darren

Edited by jet_r31
DVS JEZ Grand Master

DVS JEZ

Posted
Posted

Jase has the car been tuned on both cams or only one? And if 1 which 1?

Maybe bring it up one day and i'll spend an hour on it too see if the ignition timing is tuned correctly by the last tuner

GTScotT Grand Master

GTScotT

Posted
  • Author
Posted

Cheers Jez ill probably take you up on that hour. Would be good to get a cost effective second opinion on the tune also. As stated I think its OK but then again im no tuner. Have you got software for an EMS stinger?

As for the cam it was originally tuned for the smaller cam and then was touched up with the larger. Not a great deal of time was spent on the larger but I dont think there was much left in it anyhow. An hour on your dyno will tell us A LOT though.

Darren im thinking ill force him back to the first cam which is a stage 2, has 230* @ .50 and 114* LSA. Do you think that cam is significantly better suited or think I am wasting my time?

I'll also see about getting a housing, maybe track down the supplier of the ones Scotty mentioned or see if Stao can make me one. Would you be more inclined to test a .82 or 1.06? My gut feel is saying go the 1.06

jet_r31 Mentor

jet_r31

Posted
Posted (edited)

Id personally go back to the first cam for testing, as to me it takes one thing out of the equation, as in "theory" that one should

work fine with that setup. If you do fix the problem and its something else, then you can refit it later and re test it.

out of interest, what type of cooler is fitted?, much pressure drop?, and what valve springs? especially with big cam?

close to coil bind?, its not getting valve float from boost pressure?

The big one is something i would fit if a mate said i want a 2.6 turbo and i want to turn the world on its axis.

And even though i am no astron expert i'd spec that with a 116 LSA and a PT6466 with plenty of boost shoved up its ass.....lol

This is why i like old motors turboed and like working on them , yes they are a pain in the ass, but f**k me at least you have to

think and work some stuff out for yourself, much better satisfaction than buying most newer motors, any idiot can

get a good result out of a Rb25 etc..lol

cheers

darren

Edited by jet_r31
jet_r31 Mentor

jet_r31

Posted
Posted (edited)

I woudn't take that to heart..lol, but look at how much more info there is out there for newer motors, its like building a oversized model kit

most of the time..cars being cars, its not always going to be smooth sailing for some unlucky ones..but thats just cars in general

thats why love and hate them at the same time!

cheers

darren

Edited by jet_r31
Hanaldo Grand Master

Hanaldo

Posted
Posted

Haha nah you're right mate, I can have a laugh at my expense :laugh:

OT, I don't have anything useful to input, but I've been following the thread with interest. Keen to see how you go Scott!

GTScotT Grand Master

GTScotT

Posted
  • Author
Posted

out of interest, what type of cooler is fitted?, much pressure drop?, and what valve springs? especially with big cam?

close to coil bind?, its not getting valve float from boost pressure?

The cooler is a china 450x300 (shorter variant to the generic 600x300). Was purch back in the day from JJ, quality seems fine and no issues. Cooler piping is 2.5" from outlet to throttle. Throttle is a little small but dont think that would hold it back that much. Not any smaller than an S14 VCT throttle body from memory.

Valve springs are actually the matching item for the cam. They were purchased as a set from camtech. Im gonna try get that smaller cam back in ASAP, need to beat bro to pulling the motor as hes wanting to rebuild the motor (not that it will help). Im wanting to find the problem and then retune on a fresh motor.

Cheers for the input guys, I'll find some time to pay Jez a visit soon and see what he and his dyno have to say. Hopefully a feeble issue can be found and sorted or at least the bigger issue will rear its ugly head.

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

    • oHBoy.
      Starter motor replacment teeth count.

      By oHBoy. · Posted

      I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • suko
      J50 clock date suddenly reset to January 1

      By suko · Posted

      The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...