Hey all, :help: Bought my 300 with already upgraded turbos. Problem is that I am tuning it for tight snappy corners and turbo's are too laggy. making 10psi at about 3200 and starts making boost about 2500- 2600 rpm. Need boost (what i really need is sh#t loads of torque) from about 2000rpm. Does anyone have a dyno sheet or info on the responsiveness of stock turbos or a turbo that will do the job? Engine is stock, power aim is about 250rwks reving to about 7200rpm. will be running exhaust/ smic/ nistune/ nismo fuel pump..... will run turbo's no higher than 1.2bar (about 18psi) as car double as street car (sometimes he he). Chasing engine response and broardest torque band.... can anyone help me?
stock auto turbos will give you the best low down response but they wont make power all the way to 7000rpm and you'd be flat out to make 250rwkw with them
Not too many turbos will give you high torque at 2000rpm and have usable power past about 6300rpm. A good tuner should be able to get you boosting earlier than you are.
try gt530bbs (gt2554r) with all the supporting upgrades http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT25/GT2554R_471171_3.htm http://www.z1motorsports.com/product_info.php?cPath=6_16&products_id=3084
Here's an idea a bit out of left field, more a supporting upgrade but if you want it for corners - such as touge events, etc. how about installing a non-turbo rear-end to bring up the final drive diff ratio from 3.7ish to 4.1? The higher drive ratio essentially acts as a torque multiplier if I'm not mistaken. Not sure how involved the installation is but the R32 GTR diff is a 4.3:1 ratio and is also interchangeable with the R200 diff. (The non-turbo Zed diff) Stock Auto turbos with ported exhaust manifolds perhaps? Will choke torque at ~5500 RPM though.
Its a huge ask M8. Your unlikely to achieve what you want with a 3 litre turbo motor. Twin turbo or not. Its going to require quite small turbos but you can kiss goodby any top end. The small turbos would act lik potatoes in the tailpipe at high revs. Youd also fit some milder cams to promote bottom end. Id be suggesting a couple of more cylinder and quite a few more cubic inches. L8tr E
Thanks guys.. anyone with a dyno sheet of stock turbos in action? Believe the turbos i have are t28s inside t25 housings. Was thinking maybe a stock t25 with a 0.63 rear housing might do the trick??? Would change the rear end however already have OS Gikken tranny and am doing about 3000rpm at 120km/h down freeway. Would love to change to 4.1 final with 6spd gearbox but don't have the cash Pretty much for hill climbs and togue stuff. Still toying around for some ideas. Anyone got dyno sheets with mild setups up to about 400- 450hp. While i'm at it, anyone happen to see some 350Z 18 inch wheels for sale? Need to put on my 343mm brakes Thanks all for your input - keep the ideas rolling.
Think the GT2554R turbo's might be the go. Thanks black beast. Just need to work some calculations...but looks like it might do the job the best
Think GT17's M8. Forget anything in the 25 range if you want it to boost below 2800. This is how small your going to have to go. You could also source a couple of To2's or T2's off Pulsar Turbo ET/Exa's.. Stock trim will allow the engine to rev to about 6 (getting pretty flat after that) and pull from about 2200 @ around 10 to 12 psi. They go off the "island" after that. If you cant find a T2 or a To2 for around 80 bucks your not trying. L8tr E
With auto turbos and cams i was making boost at about 2300 or something in 5th, a bit higher with lower gears. Problem was it wasn't really making all that much torque. I think the vg's efficiency range is a bit higher. It doesn't start until 3k, so making boost earlier seems wasted. I think you would be taking a step backwards. By going smaller turbos. 2.5" piping seems to give a good torque boost. its costs 1000usd from coz. 4.1 Gears. Mild Cams. Bigger Valves.
Errr how do you figure that then? This guy want his engine to pull from pretty much idle. You cant do that with large turbos no matter what supporting mods you try. These additions you are proposing here apart from the low diff ratio will result in moving the torque peak HIGHER in the rev range and slowing down gas velocity into the cylinders usually actually reducing low down grunt. Stuff like that is usual in the chase of revs which is where the horsepower is, not low down grunt. You need to think of tiny turbos that will spool very low down but still be efficient enough to produce some higher up Hp. Highly unlikely. You just "rob Peter to pay Paul". Hes better of to play with sequential turbos, a blower, a bigger engine or just get over it and change gears more often. L8tr E
yes t2's will spool quicker but he always also wants to be making power to redline .. GT2554r is the fastest spooling that will hold it to redline with the right combination it might even spool as quick as the old dinosaur T2 style turbo
Agreed, 2554r would be close to best trade-off, it's still a trade-off though like E says, you know what would be ultimate? Getting a NA Z with the 10.5 compression ratio or whatever it is, taking off the stock plenum/manifold and customising an eaton supercharger setup running 8-10 psi or so. Imagine that on the 4.1:1 NA final drive rear end and 5 speed manual box, fantastic for the 'Touge'!!!
Hehehehehhe well, its all pretty simple. It wont happen!!!!!!!! Not very well anyway. Hes better off to leave it stock with auto cams and stuff and boost it up to about 14psi coz no matter how funky he gets with an expensive pair trick-arsed aftermarket turbos, hes unlikely to better the stock setup anywhere except higher up unless he ups the engine cubes and given hes talking limited money thats not going to happen either. You just cant polish a turd that much. L8tr E
yes it is hard task ... what about 9 to 1 comp with GT2554R... that would get it spooling quicker with top end :thumbup:
AW11 MR2 and overdrive the supercharger to 12PSI, or go and buy a twin screw charger for it, there's a mob in W.A. doing the kits, lol I looked into it a while back as a project hillclimb car haha.
