TeamCapri
Tech, Repairs, Upgrades => Capri XR-2 89-94 => Topic started by: alldsben on February 23, 2017, 11:04:15 AM
-
So i have recently put on a cone filter and a boost controller. i have only done those 2 things and have not put boost over 10 psi. if i quickly go to WOT it will over shoot to 13-14psi then quickly drop down to 10. its not a huge problem for me to just be a little easier on it at first into gear but i was wondering if i could fix this in any way. within the next few days i have an intercooler and BOV to install and was wondering if anything can be done at the same time as that to solve this issue.
-
You could port the wastegate that stops boost spikes to a degree. Its not very easy to do ill put a link on it.
-
Stock turbo and exhaust?
-
Yes stock turbo and exhaust
-
What kind of boost controller?
You shouldn't be spiking at all with just a cone filter.
Spiking is usually an issue for those who open up their exhausts, it changes the pressure drop across the wastegate, and it can't keep up.
-
I lack enough experience to comment much, but I saw your response earlier and was wondering if you are having trouble with your boost controller. Did it come with several springs? You might want to try one of the other ones if it did. Also, where are you pulling your boost line that pressurises the controller from? Could there be some gunk interfering with the boost control line? Also, are there any pinch points or kinks in the waste gate actuator line from the boost controller?
-
Whoops, yeah, what kind of boost controller? I made my comments based on the simplest manual boost controllers, not a slave setup or electronic.
-
Spiking is usually an issue for those who open up their exhausts, it changes the pressure drop across the wastegate, and it can't keep up.
I apologize for a little hyjac here, but will a 2 1/4 cat back system cause a problem?
Thanks, Jack Byrd
-
im not 100% sure which boost controller it is but i can say i know its not a high quality one. i believe it is either a problem with a line somewhere in it kinked or that my boost controller needed me to use some adapters to make the hose small enough to go onto the controller itself. i now have an fmic installed but have not had any time to drive it yet beyond just to test if it leaks at all. will trouble shoot a bit more in the upcoming days
-
Spiking is usually an issue for those who open up their exhausts, it changes the pressure drop across the wastegate, and it can't keep up.
I apologize for a little hyjac here, but will a 2 1/4 cat back system cause a problem?
Thanks, Jack Byrd
Yep.
-
I have yet to trouble shoot it but im going to try just taking out the mbc for now with my intercooler and cone filter on. But i was also wondering how bad would it spike if i went with a full 2 1/4 turbo back but still put in a cat and muffler
-
It's hard to say. There's a tremendous number of variables there.
Some folks with moderate setups only have issues when it's real cold out, and the turbo is running at a higher efficiency.
Do your troubleshooting - see if the problem persists.
I will recommend investing the time to port the wastegate - its extra time and effort but also insurance against out of control boost.
If you're opening everything up (intake/exhaust), it will be necessary at some point.
-
Hmmm, bigger throat, bigger exhaust, seems like the delicate balance will be disrupted. i think you will probably need the waste gate ported. I went 2-1/2" cat back as my only mod for a few years and my boost would creep in cold weather. So when my turbo died I went all vj11 hybrid and ported the gate to 0.87" and said goodbye to spikes and turbo lag with the hybrid. Nice powerband even though I still have the stock intake otherwise. You don't have to go hybrid, but the bigger exhaust usually bothers the waste gate. If you are not planning to port the waste gate I would strongly suggest your exhaust stay under 2-1/2". I thought I could get away with it but it eventually got me.
-
Pleading ignorance here. XR2 has a factory wastegate?
Jack Byrd
-
Yeah, it's not like an aftermarket one that would mount in an exhaust pipe, it's integrated in the turbo housing casting with a cast iron cover plate.
(https://s18.postimg.org/8toyppmax/image.jpg)
(https://s18.postimg.org/phggs7os9/image.jpg)
-
Wow, that's cool. I guess porting it is limited by the size of the flapper door? Thanks SHO
Jack Byrd
-
Wow, that's cool. I guess porting it is limited by the size of the flapper door? Thanks SHO
Jack Byrd
Yep.
And I have seen people take off the stock flapper and weld in place the business end of an old exhaust valve to gain a larger area. Probably more than is needed for a VJ14 based turbo, but, ya know ;D
-
The way I got around the spike was had a 2" exhaust from the stock down pipe added. the larger exhaust just were the down pipe makes a bend under the motor. I really noticed an increase in power out put and no spike. I think this holds the turbo from spooling to quickly until the motor can accept the air flow.I hold a steady 16 psi.
-
Ended up finally fixing my intercooler leaks and boost spiking. the only way i was able to fix my spiking was by removing my mbc. i have a feeling that is because how restrictive it was but i do not know for sure.
-
Ended up finally fixing my intercooler leaks and boost spiking. the only way i was able to fix my spiking was by removing my mbc. i have a feeling that is because how restrictive it was but i do not know for sure.
So now you have no boost control? And you must have the oem fuel cut disabled if you are seeing 13-14 psi correct? I would be careful there.
-
It would cut out when it would spike that high
Ended up finally fixing my intercooler leaks and boost spiking. the only way i was able to fix my spiking was by removing my mbc. i have a feeling that is because how restrictive it was but i do not know for sure.
So now you have no boost control? And you must have the oem fuel cut disabled if you are seeing 13-14 psi correct? I would be careful there.