nightcrawler_8

iTrader: (5)

thanks for the correction

the problem am facing is the following :

lets assume am on 3rd gear , 60mph , 2800 RPM.
i press the pedal to get full throttle. the boost level goes very very damn slow ( slower than a turtle with a broken legs ) till it reachs around 4000 ( almost 7 to 8 psi ) then it spoools soooo fast to reach full boost on almost 4500 RPM.

i will be getting the car from the audio shop next week and i will get the video recorded of the boost level.

str8dum1

iTrader: (11)

hmm 3rd gear at 60 is a good bit of momentum. it should pop to 4500 rpms super quick.

even mine rolls out dropping into 3rd at 60mph. whats your AFR like when getting on it? it should be mid 12's tapering to 11.8-12 at full boost.

those turbos should be very responsive. pretty sure they are like the 700BBs in the JWT kit.

here's RcDash's boost curve with his 2860s in JWT kit.

https://my350z.com/forum/shop-builds...turbo-g35.html
He says on page 3 hes all in by 4000rpms but the trq convertor makes it look laggier on the dyno

this one looks all in by 4000
https://my350z.com/forum/shop-builds...p-406rwtq.html

and this one prolly a lil past 4000 rpms
https://my350z.com/forum/shop-builds...p-500rwtq.html

nightcrawler_8

iTrader: (5)

now the heads work.

nightcrawler_8

iTrader: (5)

so i can say my setup is ok and this is how its suppose to be. i hate the LAG.

My compression is 8.8
HKS head gasket 0.7
JWT C2 cams.

and if i go back to the stock cams then i will get better response.... hmmm !!!

for now the A/F and timing are set for the mazimum safety as i mentioned before and am running it without the methanol injection, so i guess i will install the methanol kit, and get it tuned properly and will post up the results. if its doesnt become better then i might consider going for smaller cams. maybe S2's !!??

Glex25

iTrader: (11)

^ I would wait until the motor is broken in or at least 1200 miles before you start spraying meth.

thom000001

I would verify via logging that those are the propper boost levels before jumping to any conclusions (gauges aren't always perfect nor are we).

And I would ask GTM for some logs from other cars with similar setups to see what they got (or maybe you can find some on here).

Another question is, how does power hold through the rev range? Does it fall off early or anything?

Tom

nightcrawler_8

iTrader: (5)

will do.

its just the lag problem.. other than that . the car hold all the power till redline.

nightcrawler_8

iTrader: (5)

its already 2000 miles

str8dum1

iTrader: (11)

ya you'd have to ask GTM directly for boost curves. I couldnt find any... hopefully you can post your boost curve logs soon as well. i suspect, thats probably what you will end up with though.

Ideally for more low end, you'd still want 12mm lift but less duration. I wish they made C2's with C9 lift.

nightcrawler_8

iTrader: (5)

i have a tuning session next sunday. and then i will be able to log the boost,

i am suspecting that the problem i am facing with the lag is due to the huge intercooler.

below are some pics of the build progress.

















cleaning the covers.




















waiting for the turbo's

str8dum1

iTrader: (11)

lag due to big intercooler is a mostly a myth.Your piping and IC would have to so big to cause a huge pressure drop due to the increased volume. Your IC/piping isnt near big enough big.

If you want less lag you have to increase exhaust flow/velocity. a 50 shot of dry nitrous between 2800-4500 rpms up to 8psi would make it a rocketship!

nightcrawler_8

iTrader: (5)

well... nos is out of the equation at all..

what do you think would cause the lag then !!!.. i cannot find any justification to that..

a friend of mine drove the car and he said " WOW. it feels like a supra with T88 turbo.." a very noticable lag but once it gets into boost. its just a rocket..

str8dum1

iTrader: (11)

Multiple dynos indicated that 4000rpm for full boost is the norm for that size A/R and turbo. If thats too laggy (assuming no leaks etc), then you bought the wrong turbos. They are too big.

nightcrawler_8

iTrader: (5)

the car holds the boost very well that means there is no leak (correct me if am wrong ) , its just the spooling is very slow.


arent those turbos are the same A/R as the APS TT !!!!

str8dum1

iTrader: (11)

no the APS turbos use a much smaller housing from what I remember.

BlinkerFluid

iTrader: (7)

Standard APS are the a GT2871R (49mm inducer) in a .64 T25 housing.

Extreme are trimmed GT3076R in the .86 T25 housing.

I switched from the standard to the extreme, big diference in spool. The nice midrange torque hit was replaced with a great top end pull.

midz350

iTrader: (4)

Mine hits ~7.5psi around 3500rpm and I have a small leak and the tune isn't finished yet

nightcrawler_8

iTrader: (5)

update:

took the car to the tuner ( unichip ).. the car was very responsive to the meth injection . but we couldnt dyno the car, cause for some reason the car was slipping on the dyno so it was giving false readings. ( 680whp woot. lol )

now here is a problem i fased,

before i even take it to the final tune, i passed by the tuner and got the car tuned very safely just for the sake of finishing the bodykit and sound system installation, and the A/F was set to 10.9 @ woot, and boost was 9psi.

after driving it couple of days i noticed that my A/F was giving 12.9 to 13.4 @ woot ?!!!? :S , so i took the car again to the tuner and he noticed that the tuner didnt change at all and the same figures was there. so he added more fuel and the car went back to the safe limit.

then after i finished all the kit/audio, i installed GTM oilcooler, water/methinjection/ custom I/C sprayer and got the car ready for the final tune on 13 psi, since i have 600cc injectors.

the car was tuned as i mentioned earlier, and all was perfect. the car felt sooooooo much powerful and i got even better response that before, it doesnt feel that much laggy ( compared to before the tune, but its still lil laggy ) .. and i asked the tuner to set two maps for me:

• low boost: without methanol: tuned on 11 psi and was planning to drive it on 8 psi ( A/F set to 10.9-11.2 )
• highboost: with methanol : 14psi ( A/F 11.7-11.9 )

and got a swtich installed to toggle between the maps.

after driving the car for couple of days, i noticed that the high boost map is showing 10.2 A/F @ woot. ..!!!!! and low boost map is showing 10.8-11.2 A/F ??!!!!


now one thing we noticed, while i was tuning . the feul pressure was 52 PSI @ woot... now when am pushing it its 62psi @ woot !!!??

what do you guys think !!???

midz350

iTrader: (4)

52 psi at WOT!!! Are you sure? that is not good I think!!

My car is 52psi at idle.

Erik@R/Ttuning

Serious built list. Good luck getting the kinks worked out.