dizzyj

trying to think of everything related to engine:
balance shaft deletes
oringed head
carrio rods
manual boost controller
k27/8 turbo newly rebuilt.
3" exhaust

ok, i dont need 2k for sure. but not kicking in till 4 is a bit much. I've never had the car dyno'ed.
Does it matter if a turbo is put into a t40e housing? I'd like a direct bolt up, since i already have the LR 2 piece crossover pipe.

Can anyone quantify how much better something like that woudl be over a k27/8? again, its a bunch of coin. if it spools 100rpm earlier, then i wouldnt do it.

dizzyj

gotcha. glad i asked

mtnman82

FYI, I have a K27/6 and it reaches 15 psi at ~3100 rpm. It starts boosting about 1000 rpm sooner. There was a recent thread where people claimed the K27/8 spooled nearly as fast as the /6. Sure sounds like there's a leak or something going on if you're not getting full boost until 4K. If you can't find any vacuum leaks, I'd probably look at the crossover for leaks or blockage, or make sure your wastegate is up to snuff.

eman930

Yea something's wrong, I have a 26/8 and it hits 16psi at about 3000-3200rpm, that's with a 3" exhaust, stock DP, stock AFM, LR dual port, MBC, Late NA camshaft 4 degrees advanced.

INURGRL951

that looks like the car from an old shop in va that I had spent alot of time does it have delete balancing shafts? If so and im sure it is cause the logos or one of it had a solid 350 hp. have you changed anything on the car since it left va? and it was racing in the GTU2 class in va.

dizzyj

Ya that's the car. Bought it almost 2 years ago from va

Since then:
Gutted it
Rebuilt turbo (was shot)
New intercooler (was split)
Mtune
New mbc
Camnber plates
New clutch
New gauges
3 pc crossmember
2 pc crossover pipe
Countless bolts/bushings/etc

I'm racing it in pca gt3. It's definitely gettin loved

Paulyy

Check the crossover for leaks.
It makes a massive amount of differences.

fast951

A K27/8 should hit boost (in 4th gear) much sooner than 4000RPM. Check for exhaust leaks and revisit yor boost control.
The X-over pipe is double walls, I have seen the interior wall collapse restricting flow and slowing down the turbo. There is no way to tell if the inner wall collapsed, except to look on the inside. Or check back pressure at test port in the "Y" fo the X-over, then at O2 sensor, then after the turbo. The differential in back pressure will give you an indication of the integrity of the inner wall.

951_RS

I definitely agree with the recommendations to check your x-over pipe.

When my x-over pipe was leaking my spool time suffered greatly (to4e 50 trim - spooling at ~4k)

Once fixed it made a considerable difference.

dizzyj

ok, so what I'm hearing is fix my sh*t and keep the k27/8? im fine with that. much cheaper

333pg333

https://rennlist.com/forums/944-turb...-worth-it.html

Going off the description that this guy is having with his turbo you should be experiencing better response.

Paulyy

I don't think he has a 'normal' k27 compressor

dizzyj

bump for an oldish thread

6 months (and a new baby) later and I have rebuilt my engine. I definitely had some major exhaust leakage at the turbo hot side due to bolts backing out. I also had some major compression issues due to an extremely dirty head.

I had the head rebuilt (and ported and polished, cause hey, why not?) and replaced all the bearings at the same time. Only thing I did not do was new rings. I replaced everything with nord lock washers so hopefully the hot side wont back off again.

I also added an o2 sensor. The car had a a wbo2 in place of the nb02 spot with it run in open loop. I added a new location for the wb02.

She is spooling quite a bit faster now. hoping to get on a dyno soon to see some actual data vs the butt dyno.