N12Turbo.com lanyards are now available! Click here to visit the shop

power on paper vs driveability

General chat related to anything N12.
Post Reply
robbo
Posts: 115
Joined: Tue Jul 03, 2012 3:39 pm
Location: Sydney

power on paper vs driveability

Post by robbo »

trying to turn my exa into a better handling, more responsive street car rather than a dyno monster. with a massive gt2876r and custom manifold (so custom that it has next to no room to get it off and a warped flange to go with it) and 50mm screamer it has 133kw atw when last dynoed by the previous owner.

If i were to 'downgrade' to a stock manifold and a chinese turbo around the size of a t28 or slightly bigger, the same which I had on my ET with great results, or a kkr 380 like Chris and ran it through an internal gate, would I be likely to lose much noticeable power?

i know procrastination's like masturbation I'm only fucking myself... but after the crash i'm on a very limited car budget lol
User avatar
shanec86
Administrator
Administrator
Posts: 1454
Joined: Mon Jul 03, 2006 8:00 pm
Location: Melbourne
Contact:

Post by shanec86 »

i would rather 100kw with a usable mid range than a car with 133kw all in the top end.

A good standard manifold and smaller turbo is going to help with your problem.
robbo
Posts: 115
Joined: Tue Jul 03, 2012 3:39 pm
Location: Sydney

Post by robbo »

it's now getting a new turbo, a chinese copy gt28 as per the one i put on my ET, and a stock manifold. just discovered tonight that one of the manifold bolts had blown out in addition to the warped flange
Sohcturbs
Posts: 94
Joined: Fri Nov 24, 2006 10:29 am

Post by Sohcturbs »

Can say with some experience now that whilst it's nice to have the big numbers on paper and when it all happens you can't wipe the grin off your face, if I did it again I'd be looking to use the stock manifold and a medium sized turbo (T25ish) and push it close to it's limit for a car that probably would be miles faster within the legal speed limit and a lot nicer to drive with great reliability.
User avatar
baz
Posts: 1298
Joined: Tue Sep 11, 2007 6:02 pm
Location: Hobart / Tasmania

Post by baz »

Stock manifold, T28 from a late s14 (ball bearing) to s15 will be fine, will have plenty down low & also pull through the rev range, Run a good 14psi ish, usable power & enjoy the torque steer.
My old exa I created from granny spec to a neat little BRIGHT car: http://forum.n12turbo.com/viewtopic.php?t=3903

Current Car: 2004 Vz SS Ute
User avatar
tassuperkart
Administrator
Administrator
Posts: 5578
Joined: Wed Jul 05, 2006 8:39 pm
Location: Southern Tasmania
Contact:

Post by tassuperkart »

Your not "downgrading" going from a Disco to a China T28. It will perform more or less the same. A disco IS a T28 with a BB core.
Discos are one of the best small engine turbos ever made but are a bit oversized for a 1500. You could change the rear housing down to the smalles available for that back wheel which will improve spooling.

The only downgrade would be the manifold. Almost anything would be an improvement over a stock shitter.
At the end of the day, your going to do a lot of work and come out more or less the same so you go nowhere. WOFTAM in my view.

If you want a torque steering, tyre frying monster, keep your existing manifold/gate setup and just have the warped flange replaced with a new and thicker one. Problem solved.
While your at it, you can have all those pesky pulled threads helicoiled in the head and a decent manifold support bracket made.

Next, look into the GT25 range of turbos (GT2560) or something sized like a KKR280. lightweight fast spooling turbos that will easily outperform a disco, psi for psi around town.
Forget the bigger, slower spooling turbos which will achieve nothing over what you already have if you are going to stick with sane boost pressures.

With a good manifold design and a small and hard spooling turbo set at around 15psi or so, the car will write a smile on to your face that will be harder to remove than the black cookers youll leave on the road behind you everytime you stand on it.

At the end of the day, numbers on a dyno printout tell less than half the full story and what at first glance appears a low revving and gutless motor, can result in a real road monster that easily accounts for the biggest and bestest mofo.

Oracle
Forcd4 wrote:Oh fuk no dude it's you a again, the oracle.
User avatar
panagiwtis N13
Posts: 99
Joined: Sat Feb 09, 2008 10:55 am
Location: Athens-Greece.

Post by panagiwtis N13 »

tassuperkart wrote: At the end of the day, numbers on a dyno printout tell less than half the full story and what at first glance appears a low revving and gutless motor, can result in a real road monster that easily accounts for the biggest and bestest mofo.

Oracle
true enough! +1
i don't care:
if you're black, white, straight, bisexual, gay, lesbian, short, tall, fat, skinny, rich or poor.
If you're nice to me, I'll be nice to you. Simple as that.
robbo
Posts: 115
Joined: Tue Jul 03, 2012 3:39 pm
Location: Sydney

Post by robbo »

tassuperkart wrote:Your not "downgrading" going from a Disco to a China T28. It will perform more or less the same. A disco IS a T28 with a BB core.
Discos are one of the best small engine turbos ever made but are a bit oversized for a 1500. You could change the rear housing down to the smalles available for that back wheel which will improve spooling.

The only downgrade would be the manifold. Almost anything would be an improvement over a stock shitter.
At the end of the day, your going to do a lot of work and come out more or less the same so you go nowhere. WOFTAM in my view.

If you want a torque steering, tyre frying monster, keep your existing manifold/gate setup and just have the warped flange replaced with a new and thicker one. Problem solved.
While your at it, you can have all those pesky pulled threads helicoiled in the head and a decent manifold support bracket made.

Next, look into the GT25 range of turbos (GT2560) or something sized like a KKR280. lightweight fast spooling turbos that will easily outperform a disco, psi for psi around town.
Forget the bigger, slower spooling turbos which will achieve nothing over what you already have if you are going to stick with sane boost pressures.

With a good manifold design and a small and hard spooling turbo set at around 15psi or so, the car will write a smile on to your face that will be harder to remove than the black cookers youll leave on the road behind you everytime you stand on it.

At the end of the day, numbers on a dyno printout tell less than half the full story and what at first glance appears a low revving and gutless motor, can result in a real road monster that easily accounts for the biggest and bestest mofo.

Oracle
if i get a new flange welded on, I'm afraid that if something goes wrong with it again it will be a pain in the arse to fix, so I'm still leaning towards the chinese turbo and stock manifold. has anyone here managed to fit a gt2876r on a stock manifold with a stock radiator?
robbo
Posts: 115
Joined: Tue Jul 03, 2012 3:39 pm
Location: Sydney

Post by robbo »

caved into the pressure from the gf, car is going into the exhaust shop tomorrow, they can fix the existing manifold and take on the manifold studs.
Post Reply