Tial WG doesn't fit - need advice : UPDATE
#47
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
In your never ending quest for more - it may be time for a new turbo.
I spent 15 minutes last Monday chasing a GT2 around NHIS in a well driven '87 951 that was totally stock accept for the turbo, matching chip, and sway bars. It would have been 20 minutes but I was getting ready to toss my cookies and cried uncle.
Absolutely amazing what a different turbo did for that car.
I spent 15 minutes last Monday chasing a GT2 around NHIS in a well driven '87 951 that was totally stock accept for the turbo, matching chip, and sway bars. It would have been 20 minutes but I was getting ready to toss my cookies and cried uncle.
Absolutely amazing what a different turbo did for that car.
#48
Pro
Join Date: Sep 2002
Location: Montreal and Texas
Posts: 554
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
As you probably,already know, the reason why you have a boost roll off at high RPM, is simply due to the turbo (K26). It has nothing to do with your wastegate. No matter what you do, you will alway get that boost drop of on a K26/6 or k26/8, because it's simply out of it's efficiency range.
#49
UAE Rennlist Ambassador
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
MySwiss: I thought the K26/8 holds boost to redline due to the larger hotside than that of the K26/6
that is what i was told and knew.......
![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
#50
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
ITs my understanding that even the 26/8 will not hold 18psi right to the red line. Mine rolls off to about 15 psi above 5500rpm.
THats what most people are finding, but there are some who claim to be able to hold 18pis right to the red line. Maybe they just have a very very healthy turbo.
THats what most people are finding, but there are some who claim to be able to hold 18pis right to the red line. Maybe they just have a very very healthy turbo.
#51
UAE Rennlist Ambassador
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Slim_boy_Fat: Do you have the stock WG?
Maybe those with the K26/8 are using a Tial or a LR DP WG, but i sure know a bunch of people holding their boost to redline with that #8 K26....
Maybe those with the K26/8 are using a Tial or a LR DP WG, but i sure know a bunch of people holding their boost to redline with that #8 K26....
#52
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Givin my input into this discussion its should come as no surprise that i have the tial. ![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
Most of the stuff i have read suggests that the K26/8 wold struggle to hold 18psi at high revs. Maybe its just an issude about the accuracy of boost gauges.
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
Most of the stuff i have read suggests that the K26/8 wold struggle to hold 18psi at high revs. Maybe its just an issude about the accuracy of boost gauges.
#53
Addict
Rennlist Member
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Here's another test I did: I disconnected the line to the WG from the boost controller (Reliaboost) so the WG was running completely unregulated. (I plugged the hole in the end of the line so I didn't have an intake leak). I brought the revs up to about 5000 rpm, being careful with the throttle not to overboost. Then above 5000 rpm I added more throttle and watched how much boost I could develop. Above 5500 rpm I still saw the same boost drop (to 15 psi at redline), even at WOT. It was the same with both the Tial and Guru WG's.
There are 2 possibilities for this behavior: (1) the internal exhaust gas pressure is forcing the WG valve open at high rpm's or (2) the turbo itself can't make the pressure any more. Given that the Tial has a stiffer spring than the Guru WG, I should have seen a difference if #1 were true, but I didn't. That leaves #2 as the likely explanation. Both the Tial and Guru WG's have springs that are strong enough.
Still I find it interesting that some people, like tazman, can make 18 psi to redline with a K26/8. Maybe my turbo is just tired. Is there anyone else here holding 18 psi to redline with a K26/8?
There are 2 possibilities for this behavior: (1) the internal exhaust gas pressure is forcing the WG valve open at high rpm's or (2) the turbo itself can't make the pressure any more. Given that the Tial has a stiffer spring than the Guru WG, I should have seen a difference if #1 were true, but I didn't. That leaves #2 as the likely explanation. Both the Tial and Guru WG's have springs that are strong enough.
Still I find it interesting that some people, like tazman, can make 18 psi to redline with a K26/8. Maybe my turbo is just tired. Is there anyone else here holding 18 psi to redline with a K26/8?
#54
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by Jake951
Is there anyone else here holding 18 psi to redline with a K26/8?
Did you install an aftermarket boost gauge? I'm using a reliaboost as a mbc, bypassing the CV. Despite the claims that the reliaboost was set from the factory at a safe setting, I was getting 20 psi from it! Had to back it down. Sure ran like a scalded cat though.
#55
Addict
Rennlist Member
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by Red1
Did you install an aftermarket boost gauge?
#56
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Oh, nothing to debate about accuracy. I have an autometer too. I question it's accuracy, but a gearhead friend of mine was impressed with the vacuum at idle, so I'm hoping it's ok. Almost anything is better than the stock gauge.
#57
UAE Rennlist Ambassador
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Sheesh, now what is the most accurate gauge (boost) you can get?
I was ALWAYS told that a NEW autometer boost gauge is accurate.........
I was ALWAYS told that a NEW autometer boost gauge is accurate.........