180bfj20det

Isnt there just a setting where you can compare directly an 8 to a turbo 4 without changing any setting? If not why? Is ramp rate the "resistance" created by the dyno in order to read torque? If so, if you have a 600nm 4 cylinder and 600nm v8, the shouldnt both use the same ramp rate? Ideally, the same ramp rate should be used to accurately compare cars right? MR331037, i agree the dyno is a tuning tool. But there is no better back to back comparison bt different cars comparing power than using a dyno...the track offers too many variables such as traction etc. Im just wondering, on a dyno day, is the shootout mode just set on the one mode or changed for each type of car?

It wont throw a rod unless you run big boost. I rekon 14 psi and youll be fine. Just get it tuned properly. That said, I dont know about the strength of the RB25DE bottom end, but I cant imagine it being weaker than NA SRs or CAs which can handle 14 psi on stock bottom end. Go it!!!!

Sorry to turn your thread into a poo thread. No pooing from now on please :sorcerer:

Upgrading to large cheap chinese cooler made my lag decrease. Why? Because old cooler was restrictive and poo. I had a run in with a jap-tuned cefiro running a 2530. Was a fast beast. Lot less lag than I have but hey, Im not a street man, just the timeslip counts. The 2530 pulled very well from low revs. 2530 and youll be happy. GT28rs is the same thing mate (almost) except you can buy it brand new from garrett with warranty. hpinabox.com. cheers

I was thinking the same thing. I spin in 3rd when planting my 400rwhp datto with 195s and stupid camber......but with 350rwhp I hardly ever did...not to mention the 280rwhp you have. No offence but whats the go? Get those af ratios to 12 and youll be making more poke. Well done but do as above and enjoy more power.

I say a good manifold is never a waste because it can always be beneficial down the track which most of us seem to go down these days. However, like others have said, another manifold is not needed and THAT manifold you have shown us I would NEVER touch. What a piece of crap. If you get an aftermarket manifold, Id never go for anything less than equal-length runners... and that crappy manifold you have a pic of has three runners collecting into one runner far before the collecting flange. A big no-no (it create hot spots and associated irregular thermal expansion*) if you dont want your manifold to crack, especially in this case being stainless steel. * reference maximum boost by corky bell

The link ECU is far from your problem. Get someone who knows how to tune it and youll be away. Ben Diggles runs a 9.18s quarter with an FJ20 and a link ECU. The car is not a typical drag car. Ie almost full weight, is street registerable (but isnt because he choses not too)....meh, the point here is that he uses Link and it controls his engine beautifully and considering it is producing 600rwhp, this ecu would have to be good because at the power level, control needs to be perfect remembering that this power is simply from a 2L 4 pot engine. First of, if you can, post an ingnition map. Itll be interesting to see what it looks like. Secondly, as someone mentioned before, get some attention to those air fuel ratios. They should be 12.5 max on that boost. Its best to be on 12 if you want ot be safe. This will also see more power. So get a tune is really the answer. Get the ign and fuel maps adjusted and you should get to the answer of your problem faster. Those humps look like a valvespring problem. Are you sure the engine is a turbo variant? Looks like they are staying open at higher rpm and boost. Same problem I have!!!! I wish I could help more but there are experts on this forum who will help you like cubes and sydney kid who helped me get to my problem which was similar to yours....weak valve springs.

Im pretty sure all BB turbos (genuine ones) from garrett and hks have inbuilt restrictors. Therefore no need for this restrictor for your "mismatched laggy" gt3040r. Disco could confirm this. Let us know how this turbo goes cause apparently, they are laggy

Dam, I save SKs posts and keep em in seperate folder entiled posts by SK. His knowledge is just as good as his willingness to help. Eventually I could put a book together from his helpful posts and sell it Well kidding about the latter.... SK can I send you my dyno sheet and could you predict my time?? Hahahah, get your crystal ball out and you could make some cash!!!!!!

Water injection is a very good thing. We dont do it enough here in oz and still get awesome power figures. I think we could have the most powerful cars fullstop if more of us used water injection. In the UK, water injection is used or more occasions. An example is a CA18det s13 strack car which has been running for many months now (years?) and is making 483rwhp. http://www.sxoc.co.uk/images/dynamic/membe...61141441306.jpg Mind you its runs 265 degree cams, forged internals....blah blah. But it makes this power thanks to water injection and 2 bar boost. A few of these 600hp GTRs who frequent this site could see quite a bit more hp with water injection. Im all for it

jEESH? 8500rpm from an rb25.....what mods you have to your engine?

Tell me, what is the "real life " advantage of using lets say the hks 2835 turbine instead of the 53mm turbine from the GTRS if we use the 71 compressor? Are we talking less lag or just more top end? Cause Id rather have less lag, less top end power and the 250rwkw the gtrs can deliver in the small 0.64 housing than using the 2835. Explain this. Also, you say you dont beleive it (53mmp turbine) could drive the 71mm properly...hey, Im on the ball park with you, remember the thread I posted about the 15 percent rule where the 2871r is turns out the be the worst....but beliefs and reality are different. Like I said, NS.com houses many a dyno curve from CAs and SRs getting full boost at 4krpm and making 250rwkw on 15-20psi. Now theory/on paper is one thing, but reality maybe different and clearly here the 2871r is a success regardless of the "inefficient turbine". Fact is, this turbo is very good and I dont believe its "just" a substitute for the 2540. In the end, Id really like to know whats best and "off the shelf" available as hybrids...as someone has said, no-one in australia nor in any other country spends the money on R and D like HKS do. Garrett obviously spend loads too and have decided to bring out the 52 trim GT2871r. Dyno results prove its a good thing. Its all very confusing.

Funny you say that...didnt you once mention youd go the 48 trim GT2871r if you could go back and turbocharge your fj???? But like you, I find it hard to believe the 53mm turbine could drive the 71mm compressor. But it does and very well so. You frequent the NS forums...have you seen the 2871r thread there?? Srs and CAs making 230-250rwkw, full boost from 4k rpm. It flows, may seem small like I said in my previous post but there is more than enough proof isnt there (check it out on NS for yourself). And remember this is for the 56 trim. The 52 trim will be less laggy albeit make less power (gtrs equivalent). HKS know what theyre doing and so do garrett by having brought out the 52 trim 2871r. May seem bad on paper, but the 52T in 0.6 compressor housing works well.

Now please dont take this the wrong way. I find it hard to beleive a turbo that looks identical to the stock s14 sr20 t28 with simply a 71 compressor wheel could put out in the 250-260rwkw range....its not the 71 compressor I find unbeleivable, but the small 0.64 exhaust housing with 53mm turbine... I have one in front of me now, and dam it looks so small (the 0.64 housing). This thread is about dyno sheets and the HKSGTRS, how about some times sheets to go with it..?? BTW, out goes the door for my GT30r and in for the gtrs

What? I have one on my car, and it sounds...hang on, youre absolutely right!!! The worst ever sounding gay high pitch "look-at-me i squeak and cant even sneeze" valve on the market. They do functionally work well (open on low boost and dont leak at high boost) but mine is getting the recirulating treatment. HKS claim "an aggresive sound"....this is about as good a claim as that the HKS2540 is a good turbo. Ive had my bitch, but if you think the HKSSQ is gonna sound good, your in for a sqeaking surprise unless your the type who shaves you legs....

Bigger isnt always better, its just better than smaller. Going to big adds weight. Fact is in Australia, we chuck 3" on everything from 600hp GTRs or XR6s to 200hp CA18s. It works but for example, the CA18 could make exactly the same power as with a 2.5" exhaust unless youre chasing more than 450hp at the engine. Even most street WRXs are fine with 2.5" exhausts and make no more power with 3" exhausts. All this is within reason and notice I said "most" and "street". Exceptions always exist. http://www.turbomagazine.com/tech/0212tur_exhaust/ Turbos operate best with no exhaust backpressure (Quote Bell's book) so you can see where the fact bigger is better comes in, but remember there will be a point at which bigger is going to yield no more flow and just add more weight. Also, surface area is no good for comparison, you need to use pipe volume with respects to resistance, pressure etc which is a fluid dynamics formula. Quite simple really, so dont stress. Look it up on the net Boosted frog

http://video.google.com/videoplay?docid=-7...90388&q=skyline Thought I may as well post it here since its a skyline and I cant find anyone who knows how to get this sound. I assume its turbo flutter due to no BOV. The car runs a T04Z. This is not a flutter thread so dont attack me on this one please, I know there have been 1000s of threads regarding flutter. All I want to know is how to get this specific sound on lifting the throttle cause I like its high pitch aggressiveness. Anyone care to share or if your car sounds like this what turbo are you running, are you running AFM, etc. Cheers

Mate you got jibbed by an eBAY turbo. These dam things should be made illegal. YUK

Noone will show you a turbo that is rooted due to running no BOV. Its "theoretically" possible, but NOONE has proven it and NOONE will. Its myth and BS. I have two s13s that have never run BOVs and turbos are still in excellent condition and both have been running for 16 years.... BOVs are to reduce noise. BOVs are to stop your cooler pipes from blowing apart if your piping is dodgey. Thats it. So please, before another person says no BOVs damage your turbo, post some proof. Guess it stops there, 16 years of no BOV for me is proof enough BOVs are not needed. Now its just a personal preference what sound you want, flutter vs everyone-look-at-me-I-sneeze.....so keep it at this cause it wont be proven BOVs damage turbos.

Hang on, are you saying that if I buy a GT28rs from ATP with the 0.63 AR ex housing, that it will be a 0.63 AR housing calculated on the size of the GT30 60mm turbine and not the 53mm turbine from the GT28rs? If so, unless I got it wrong, that still works out to smaller AR than the garrett 0.86..... If I were to go for the flattest, largest in magnitude and earliest torque curve (yes the combination of the three ), I will benefit from using this 0.63 housing as you say...(pending explanation) but could I benefit from blocking of the gate and runnung my Tial 46mm gate to ensure the least back pressure in the housing too? Last of all, you talk about reversion which is very impt, could I benefit from a split pulse manifold and housing? Summary: GT28rs with ATP 0.63 TiAl gate 46mm Split pulse equal length 1 1/4 inch manifold Split pulse housing Heeps of torque really early and 330rwhp? Add more to the equation of need be please... Last question of all, since this thread is about matching turbine to compressors...why do you not recommend the 52 and 56 trims and only the 48t in the gt2871r??? Also, why just the 0.86 housing? There are a few on nissansivlia who make 320-340rwhp at low boost (ie 15psi) on srs using the 56t gt2871r with 0.63 housing.....take this into consideration when asnwering cause from evertying I have ever read from you (which i appreciate), it contradicts what you have said and im confused as hell now Thanks a lot Boosted Frog

Disco, Whats the diff bt the HKS 2835pro s and the 2871r 48 trim garrett? Also, I really dont see the GT28rs pulling 330rwhp....can you? How much of a difference really exists bt the rs and 2871r 48 trim in drivability? Cause I think for what I want, the 2871r 48t is the go...remember 330rwhp as I already 307...and i want just a lil bit more!! Also, I use 98 ron bp and I need valve springs cause my NA head valve bounces on boost (anything over 13 psi.....).

If the GT2781r 48 trim can get me the 330rwhp...then let it be!!!!! Why 330 rwhp...i dont think a std FJ head will flow more than that on street fuel. Ive seen more, but i rekon dynos tell fibs sometimes... Maybe with cams and some head work you can get more..... I want something responsive and fast on the street, so if the 2871r will do it, so be it!!!! Itll have to be much more responsive than the t04s GT30 i have now yes with mammoth 0.7 cover (ouch). Whats the diff bt the HKS 2835pro s and the 2871r 48 trim garrett? Thanks for all the help.

Ok, what about the GT3071R externally gated version with 0.5 cover? Is this a better match ie the GT30 60mm turbine can drive it better? They claim it spools 1000rpm ealier than the GT30R 6/12 bladed 0.6 AR turbo and it seems ideal to put out 330rwhp..... Thanks

Thanks for the reply. Disco, you seem to overall agree with the fact there must not be too much differenc in size bt compressor size and turbine. I agree with you. But lets refer to the 3040, the one from Garrett and the other from HKS. Now I dont know about the specs of these turbos exactly, but since this thread is about matching turbine and compressor size I will leave it at this with respects now to trim in addition. I get the feeling you agree that the Garrett GT3040 is a mismatch, and infact Im sure you have said this time and before in an another forum (apologies if I am wrong). Now it runs the 56T rather than the 50T and 0.7ar and 0.6ar respectively for Garrett and HKS variants. You say the HKS is superior, but can these small differences in AR and trim make all the difference? Lets compare 3 Garrett GT30s - all with 60mm and externally gated: 1) T04S compressor (7-bladed) with 0.7 AR cover 2) 6-bladed GT wheel with 0.6 AR cover (proper GT3076R) 3) 82mm GT40 compressor (GT3040 talked about above, supposed mismatch) Clearly "2" is the winnner. Less of a mismatch and plus less blades and smaller AR to achieve the same flow (compressor maps avail at atp turbo). Now I dont care about peak power, so take this into consideration for the next question: which turbo would make your car fastest on the same engine eg FJ20 as you love it or lets say an RB25? If the GT3040 is mismatched, it will lag then eventually produce power = slow. If the 6-bladed is better, it will make power far earlier taking into consideration the smaller AR, wheel and trim (i think for the latter) which will make it a faster car. If you can describe other characteristic differences bt these 3 turbos, please go ahead. It may just allow me to understand more of what is going on. I have read everything I can but I cant clear things up. So these questions are not here to annoy, but simply get a "deeper than normal" understanding of what is really going on. So please dont hammer me for not knowing and asking Cheers

The topic of turbine and compressor matching has been bothering me for a while (more than a year) and with all these turbo combinations on the market available now, which seem to work quite well in certain applications but not others, Id like to have more theoretical and practical input from people on this forum. American racers a while back set themselves a rule of thumb through years of race proven research: "compressor and turbine external diameter must not surpass 15 percent". Looking through garrett's range of turbos: GT28R - 53.35mm turbine and 60mm compressor = 11.4% GT28RS - 53.35mm turbine and 60mm compressor = 11.4% GT2871R - 53.85mm tubrine and 71mm compressor = 31.8% GT2876R (aka GT2540) - 53mm turbine and 76mm compressor = 43.4% GT3071R wastegated - 56.5mm turbine and 71mm compressor = 25.7% GT3071R externally gated - 60mm turbine and 71mm compressor = 18.3% GT3076R externally gated - 60mm turbine and 76mm compressor = 26.7% GT3082R (aka GT3040) - 60mm turbine and 82mm compressor = 37% GT3540 externally gated - 68mm turbine and 82mm compressor = 20.6% the only turbos that meet this rule are the: (1) GT2860R (the same turbo as the s15 200sx) (2) GT28RS (aka disco potatoe or GT2860RS) (3) Externally gated GT3071R Now the performance of the GT28R and GT28RS are proven and no one can argue about their performance. I have not seen anything on the GT3071R externally gate version yet so if you have info, please do tell. If anyone can post the specs of other turbos like above then comment with respects to ths 15 percent rule and their performance, it would be great. Who agrees with this rule? If its to go by, then the GT2876R is a definate mismatch and this is known (favouring the rule) but then also the GT3040 and GT2871R are bad combos.... Cheers