Hi Zedders, Lately I have had some confusion and need some great help and solving. My big build has come to a fork in the road. I have researched for over what seems a thousand hours crossing forums and am now circling..., to try to find out my answers. In the last two years, I have accumulated the furious line up of parts listed below , and what now lays ahead of me , Is the crucial choice of picking...Cams and Turbos ? To tell the truth, I just can't quite pick up on a understandable combination. What i am looking for is a cam/turbo combo that has a good power curve. When i first started my build i favored big is best...i.e. 3071...3076 Jun 272,....but 272 idles at 1200 and starts at 3700? Im not liking the idea of what some threads describe as a "hammer" effect when the turbs kick in at xxxx rpm ? A smooth uprise on the power curve is what im wanting right throughout the rev range ? Whats the best dynochart anyone has seen. I found one recently but lost it....US300 forums? My desire ,... is for a quick streeter/weekender/build. EPR Machined/Prepped Engine block EPR Modified Oil system in block EPR Cylinder Bore Coating Wiseco Pistons EPR Tops and Skirts Coating Pauter Rods EPR Modified High Speed Crankshaft Clevite Bearings w/ EPR Coating NA Oil Squirters ARP Main Studs ARP L19 Head Studs EPR Oil pan Windage kit EPR 8qt Sheet Metal Oil pan The Fire breathing Heads.... EPR Intake/Exhaust Porting Service EPR Coated Intake Chambers EPR Coated Exhaust Ports EPR Coated Combustion Chambers Ferrea 1mm o/s EPR Valve Coating Service Ferrea Dual Springs Ferrea Titanium Retainers Ferrea Seat Locaters New OEM Hydraulic Lifters Honed lifter bores w/ EPR Coating Service Cometic Head Gasket EPR Ported Oil pump AMS Manifolds w/ EPR Porting & Thermal coating Turbosmart Megasonic BOV's Winfactory Top Feed injector System 755cc Bosch Injectors Denso Irridium IK20 5304 Spark Plugs Splitfire Coilpacks OS Giken Quad Plate Clutch [/IMG] (It weighs a whopping 20kg) Magnaflow 3 Inch Cats Magnaflow 3 inch X Box Magnaflow 3 inch Mufflers AMS Radiator Leader Gears etc,etc... What will happen if i run with... 3071- Jun 264 (Im favoring this the most) or 3071 and Tomei 260 / 10.25 lift? (What happens here) And whats the diff between a tomei procam and tomei poncam ? hyd-solid? I want to retain some low end. I keep thinking the leader gears will make up for what i want? Other cams ive found.. Shneider Tighe Stillen Nissan Motorsport(Nismo) HKS (possibly extinct) Am looking to run with Ashspec massives and piping [/IMG]
Omg that's sweet ! Imagine if it opened up on one side to reveal a BBQ & the other side a fridge of cold beer.. Mmmmmm Sorry for not having any advise for you. Also just wondering how your going to drive the toolbox once you put the new motor in it
If you want smooth power you can't really go past gt28rs with the tube intake like black beast is doing. Not going to deliver the same top end ad those other turbos you mentioned, but in terms of achieving the most area under your power curve I don't think you can do any better. Check out the dyno from UAS 456rwkw motor, pretty hard to beat. Jun cams will give you more response than jwt. Jun 264 sounds like a good choice to me but I don't think you will spend much time in the rpm range where the 3071 operates... Oh and yeah nice toolbox!! How soon is this thing going together? I'll be interested in your thoughts on the leader gears... I have a set but am very much in two minds about fitting them to a big hp build. Lastly I dont know about the title of your thread mate, there ate a few peole that wouldn't mind having your "problem" ha ha
I have to agree with Rob's choice in turbos. Actually, I seem to agree with just about everything he says. Only because I don't know better. I searched till I went green around the gills and my final choice is the gt2871rs's. That's good news about the cams too Rob, just got some JWT 400+ jobies. Tool box? I was looking at the zed.
Crikey 3071's, 260 duration + and big valves/heads... but want smooth delivery and lower ed. Well youll get a smooth bottom end allright, all 90 Kw's of it lol! Stand on the throttle: Waiting...waiting....waiting.... HAMMERTIME! "oh shit, why am i looking into the scenery thru the windscreen and the road thru the passengers side window?"!!!!!! Launched from the barrel of a gun anyone? Plenty of tyre frying fun but would be crucified by a mild, boosted build in all but 100mph+ highway rollons and dyno-queen pulls Id predict! Think milder than you actually WANT!!! Id love to go for a run innit tho! Keep us posted. L8r E
*you should be asking EPR what cams suit the heads he ported . *as far as smooth power curve throughout the rev range : As soon as you go to the 71mm compressor wheels the spool comes in later and more violent ("hammer" effect you mentioned ) *tomei procams are solid
Thanks guys. I'm quite stuck right now. My computer has "accidently" gone through a system recovery. What a mistake to go through. ALWAYS back up your files guys.
GT28RS's, have a look at what the Slot Car did with them, hell impressive. Otherwise if you want a Dyno Queen, the 3071's. The GT28RS is a well matched turbo, the GT2871R is not and will suffer from a greater amount of inertia/lag and not have the most linear power band. They will offer more HP given the larger compressor, but the 3071 is most likely a better choice at these EXTREME power levels - they make the power significantly easier at less boost, and will not choke up the exhaust like the T28's do high up the rev range. My 2 cents, I'm no expert but this is my understanding.
Well , I've done the research reading back and forth and as best as i can. And have come to this.... (I should warn , I think I'm doing this build alllll back to front lol. Because it's really stressing my head) If i look at the build and subtract any "eventual" choice of turbo for the future,...(GT28RS--700's--3071 etc ?). The main hurdle that then remains for me is in - that the porting work on the heads, is very well thorough. Coated If i think on it and really just take my "eventual" choice of turbos out of the build equation altogether , .............and look "solely" at what cam duration would work best with the new increased head flow. I would very much want 272 spec on that base alone. But since its a streeter, and i want low end, I'm best to opt for Jun 66 (264). I've searched everywhere i know of, but today , went back and sought Kabir's zed. The build, the figures, and future developments look promising. But this is touching back on 3071 convo. Either way.. As a learner this is endlessly confusing, but the way i look and see it .......If i were to use Jun 272's, "WITH" any turbo,.... my heads would breath horsepower very well. And then , any "TURBO's" within this case , would work too the Jun 272's full extent. But, overall, the vehicles low end range for take off would suffer. Soooo, since its a streeter , and i want low end , I'm going to opt for running Jun 66 (264). If i run with Jun 66 (264)....The heads will then , only operate at a diffirent head flowrate , when compared/oposed to Jun 272 duration. Annnnd in that, I will retain low end takeoff no matter what turbo's i choose. It's the head modifications that almost trip me over my hurdle
we got 240Kwrw with standard turbos 15 psi boost 1:13 wakefield and 1:24 oran park GP circuit need low down torque out of corners for good times. The skyline has more power slower times T07 comes on at about 4500rpm too late to be helpful then too much power for a short duration to 7500 rpm 300ZXTT 7 secs faster at wakefield
... Just wanted to highlight on what you noted on here....... "Jun 264 sounds like a good choice to me but I don't think you will spend much time in the rpm range where the 3071 operates..." ??? Is this because the 264's rpm range will drop off short (6000-6500rpm?) and not be able to enable travel right through to the 3071's best rpm's range.
your stuck inbetween good spool for street and dyno queen status my choice now that you have gone this far .. 272/gt28rs cam will match the head and work well .Gt28rs will still give you a decent spool (but Again why havent you checked cam choice with EPR.)
I have asked EPR. I'm wanting to run by the AU forum as well. I need to pull my head out of the US300 big builds. The build was all set going ahead with R5's. I had purchased R5's from Mitchell then news came about on the JWT reduced base circle issues. I asked Mitchell and he let me off on the R5 purchase and that enabled me to move away from the R5's and i have since been trying to look at what is optional. The builds full picture suddenly dropped upon me. It's such a nice build. I wouldn't want to waste any of it. And ever since the pick of new cam choice has arisen , i have become more and more divided. If the heads are line bored "for" jun 272, and later on i see 264 would be better option, Will i be able to interchange both durations with the new line bore ?
Well the bigger you go with the cams the higher up the rev range you move the powerband. As Black Beast said you need to decide are you building it for response or dyno numbers? If you just want to pull the most HP out of it possible then go for the biggest cams and turbos you can find. If you want it smooth then you are going to need to sacrifice some top end power...
