My Car Is A Laggy Pos, Suggestions?

[Nismo_Boy]

Hey guys and girls, just after some feed back/ideas on things I should look into with getting my rb25 on boost quicker and to make it a lot more power happy down low, current mods as follow below;

Rb25det rebuilt with forgies, ported head, HKS 275 camshafts, top mounted trust Td06-25g turbo, trust 50mm waste-gate, trust front mount intercooler, trust Oil cooler, GReddy Type-R BOV plumbed backed, 850cc injectors, 3inch dump pipe, 3inch dump pipe back exhaust and an evil HKS F-con V ecu.

I understand it will never be as exciting as it would if it were a smaller turbo, but I'm sure there is something to make it a little less boring until 3800rpm? I assume the tune would be a big factor? Would getting the f-con re tuned or even ditch it altogether help?

Thanks.

[BU5TER]

Sell it

Oh thats right your trying to hahahaha

[Roy]

A bit more info of what power it is making now, what boost and even better a dyno sheet would help. But if you are making meaningful power, and it gets going at 3,800rpm...i dont think you are going to improve much on it

[Nismo_Boy]

Sell it

Oh thats right your trying to hahahaha

<{POST_SNAPBACK}>

You know me better then that Brett! All my cars are for sale!

[Nismo_Boy]

A bit more info of what power it is making now, what boost and even better a dyno sheet would help.  But if you are making meaningful power, and it gets going at 3,800rpm...i dont think you are going to improve much on it

<{POST_SNAPBACK}>

490rwhp on around 1.5bar with advanced timing and jungle juice.

[R31Nismoid]

was gonna say that wouldnt be street fuel

getting a -25g coming on @ 3800rpm IMO is pretty damn reasonable.

Its a trust turbo... thats thier behaviour.

Nothing nothing nothing... KAPOW

Where is it making 1.5bar?

[Nismo_Boy]

Can’t really remember 100% as my dyno sheet is in another country (long story don’t ask). Pretty sure it was very high 4000rpm, maybe early 5000rpm, either way it starts to sing at 3800rpm.

I have my suspicions my turbo is a freak.. Some form of high flow jobby, not really sure.

[R31Nismoid]

sounds about right in the high 4000's.

thats just the turbo. you might get 200-300rpm better with r&d, but not much more

[NXTIME]

I don't see why you are complaining.

[Nismo_Boy]

I don't see why you are complaining.

<{POST_SNAPBACK}>

My car is boring and has no life off boost. I was hoping maybe a different cam shaft selection or maybe trial and error on the dyno with some tuning would make it more lively in the low rpm range. I know I will never get that “kicking you back in the seat” feel a nicely set up GTR with aftermarket low mounts have off the mark, but a td06-25g really isn't that big of a single to make my car feel like a diesel Pajero until 3800rpm B)

[Nismo_Boy]

sounds about right in the high 4000's.

thats just the turbo. you might get 200-300rpm better with r&d, but not much more

<{POST_SNAPBACK}>

Typical non-ball bearing turbo eh. I had quote from GCG to convert it to ball bearing, worth the time and money in every ones opinion? Or is my money better spent elsewhere?

[R31Nismoid]

dont convert it.

Just get a GT30, itll be on full song around 4300rpm, and making boost well before 3800

It'll make less power, but the car will feel a lot better

[T04GTR]

I was not aware you could make a mitsubishi into a garrett.

try retarding the exaust cam abit(like 2-3 crank degrees)

those cams wont help,what exhaust housing is on it.

is it a tdo6H or a td06 (25g ie t67)

ive got a 14cm tdo6 housing that may suit. but you need a 10-12cm one it seems

they are a mad turbo but hit with a rush. :lol:

[mokompri]

I was hoping maybe a different cam shaft selection or maybe trial and error on the dyno with some tuning would make it more lively in the low rpm range. I know

<{POST_SNAPBACK}>

running shorter duration on the cams generally gives better low down power, maybe stepping down from 272's to 264's

playing around with cam gears you should be able to shift power around on the rev range

running higher compression with thinner gasket if you have a thick one, higher compression will again give better low down response

maybe lightened flywheel as well, wont change the power your making, but will make the car more drivable when its off boost

theres some suggestions, the first 3 will most likely lower top end though

[Nismo_Boy]

Thanks for your reply’s lad's.

R31Nismoid, I think if I went to a completely new turbo I'd just buy a HKS 3037 or something, I doubt second hand turbos are worth much, almost wouldn't be worth while selling mine.

T04GTR, mine is the 25g exhaust housing.

mokompri, I'm running an OS Giken flywheel and twin plate clutch so I guess the flywheel should be lighter enough? I'm going to look into cam price's I think, losing top end HP doesn't really faze me much these days, I guess I'm just after an extremely toey street car, with minimal lag with out having to change anything really major.

If only we could have it all lol

[R31Nismoid]

without going major change (read turbo) you aint really going to get a minimal lag setup with that turbo unfortunately

[mr_rbman]

rb30 bottom end would help but you have a rebuilt bottom end so i'm guessing you wouldn't wanna go that far!

[RS500]

nismo_boy,

maybe you should look at the sizing of the exhaust housing and step it down if it's anything bigger than a 10cm^2.