GTScotT

That's the next internet star, set to become the next big thing on all the good meme websites.

LOL keep it coming, come on. Just a little more.

Sure. Just give it up mate. The forum is for useful info not for winding people up.

Dont get whiplash from those twin turbos Sheeny, they will get ya round rooty hill quicker than a supercharged commo any day!

Funnily enough our current guest entertainer has put a number of WTB and FS posts with his phone number on them, forming the majority of his recent activity. Rather than discussing the concepts of twin or single turbo setups perhaps someone who is not on a work PC should sign his mobile number up to a few gay chat/gay porn/free ringtone websites. I'm sure that would keep him busy. In case nobody has the time to look up his number its displayed as 0421854393. That number again: 0421854393. Glad I could be of service. Rad as dudes!!!

This thread and the RB25 dyno thread have them all. You aren't looking hard enough. there are a number of T67 results and a couple of 20g to compare it to.

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.

First time for everything ;-)

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

You did try non surge without vct also right? for a like for like scenario anyway

+1 for hypergear. also say ditch the FPR and keep stock. HG SS2, 3" metal intake, eBay cooler kit, injectors and a plug in map based ecu. hypergear can bundle a turbo and ecu at a great price. Buy 850cc injectors at least. You will have an awesome car. GL.

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.

Have the CHRA number now, sorry for the delay. Part number is 700177-5007. I hope that bestows a little more faith in some lol. Discos part number thread: http://www.skylinesaustralia.com/forums/topic/104500-garrett-gt30-turbine-based-bb-turbo-and-chra-numbe/ Darren do you think the LSA could be causing that much grief? Considering the super quick spool and shifted powerband I cant help but think the turbo is mostly to blame. Its essentially getting onto power and coming back off exactly 2500 RPM in both directions. I tend to think that if something was as fundamentally wrong as has been mentioned that the outcome would be a lot worse. Unfortunately the original cam was what became the smaller of the two cams (114 LSA) and we dont have a stockie anymore. A magna cam also doesnt fit due to the water pump extension. Short of spending crap loads of money I dont think there is a simple solution, and I dont seem to have many people agreeing that the turbo is the issue lol. I am fast warming to the idea of an RB in this thing

Thanks again guys. Thanks for mentioning the phasing too Dale (and your other great info), I hadent considered it too much. Been too consumed by my SR build. Im going to be really keen to see this cam now. Once ive double checked mechanical timing i will actually rotate the motor by hand to see the valve events take place. Being a single cam with over rockers it will be easy to see the transition from exhaust to intake stroke on the same cylinder and ill try work out if its got some crazy overlap going on. Daniel I will definitely run though those things yeah. I still do feel the .63 will be too small though. Maybe hope is still on the cards for the GT30 though. Neil how sure are you the factory T3 was a 1.06? If so thats good info and gives me an indication that these things do at least need a big housing.

Hypergear has mentioned in the past that testing on port covers proved that the a minor amount of response was lost and it required more boost to make the same power. Surge point was obviously shifted and his recommendation was to only run a surge housing when required.

My cars torque was OVER NINE THOUSDANDDDDDDDD Just wanted to belong

LOL if it had a cat. Its literally just a pipe under the car. With the smaller of the two cams it had less power but IMHO a better powerband. Ive been trying to get the smaller cam back in it for months (along with a .82 housing) but the bro just wont have it. Wants proof this combo isnt good before he does anything. Might just take it off him for a while and work out some things myself. I want to do a COP setup too which should help with getting the big numbers once it can actually flow them. Have LS2 coils ready to wire in.

Hey Guys, As the title states, I have an R33 auto 5 bolt 4.3 diff in virgin like condition (whole car was stock and unmolested but badly rear ended). I would like to swap this for a 4.08 or 4.11 diff for my S14. If its a 6bolt with the 3 x 2 bolt half shafts that would be even better. PM me to proceed. Thanks,

LOL I hope your laughing with me and not at me. I've not dismissed anything anyone has said, and I will be looking into mechanical timing at the earliest possible time per your comments. Short of that I do want to 'cost effectively' trial a larger hotside.

No head work Dave, luckily! Otherwise id be majorly pissed. At least Ive got the excuse ATM that its just a POS sigma lol. Darren would you consider selling your spare 35R or take some ransom money so we can trial it and send it back? If its too much hassle I understand completely.

Short of the cam having skipped a tooth I'm doubtful that the problem is as heavily dependent on the tune as you guys may think. I have looked at the maps in the past, and know the AFs. Theres a reasonable amount of timing about the place and its neither rich or lean, from what I can tell its tuned OK. I wont put the tuners name to it as I dont believe hes to blame, plus I think forum rules are against it anyhow. I have had and had friends with multiple other cars tuned by the same tuner all with peachy results. Lith what is your gut feel? Again I dont think it can be compared to a SOHC 4G63 as its a much longer stroke motor. My gut feel says garbage head design with the long stroke below is making it overspeed the turbine an an early rev, and its willingness to hit high boosts is hand in hand with its inability to take on more flow. So while 18psi worth of 3076 should be 300kw worth, its really only 18psi with a motor as efficient as an RB. I should note that on gate pressure it makes a relative amount lesser power, and feels more along the lines of 120kw than it does 170. Same goes for if you take it back to 16psi etc. We arent keen to push more than 18 as its already getting white hot very easily. Lith the EGT are ALWAYS above 500*C, a squirt or two and its above 600. I dont want to thrash it to see what happens then lol. Trying to keep the block reusable so we can rebuild it once this is sorted.

I know there have been numerous high power .63 results with and without the use of WMI and E85. There are plenty of RB25s on pootrol making 100KW more than I am on the same turbo... However, this isn't an RB(of any kind) by any measure. I have been of the strong belief that simple flow capacity is only one element of a much larger dynamic equation. Where the same CFM of flow, for the same CFM of power, will need two different turbos across two different motors. Got to remember the Astron is an old 8v clunker with its spark plugs sharing space with its exhaust ports. A lot has changed, so we cant really compare it to results from modern motors. Thus leading me to this brainstorm thread.

You dont think the turbo is flat out too small? The fact it does come on mega early and does a 'good job' of its 170kw (larger cam) indicates to me its running OK (aside from obvious power problem). In all other cases I've seen with whacked cam timing the car is generally laggier and down on power, plus not driving well. This DOES drive well, just has nowhere near the power it should have and gets super hot super fast. If I took someone in it and said it had a T28 they would think it was farking awesome lol. I will redo cam timing to be sure, it was last done by my dad (highly mech skilled) but I've never done that one myself TBH. From memory the head comes off these motor with the cam gear still in place and its a double chain, so I am doubtful of faux pas on his behalf. But I will check myself to be sure. Exhaust is 3" straight through, mufflers are straight through types without chambers or bends. Thus ruling out the exhaust, unless a sigma needs > 3" to hit 200kw which would be lol'worthy but unlikely.

That china 4 bolt housing looks OK, if only it came in v band out. I dont actually have a GCG hack housing on it, its all genuine garret. Got a genuine garret GT 3" Vband .63 external gate rear on it. Some pics: