Author Topic: does a vnt gt22 have a waste gate? (Read 5213 times)

oldskool rich · « **on:** November 10, 2008, 05:44:11 pm »

i just came to put drill a hole for a waste gate and my mate said why isnt there already a hole for one? im used to improvising that the thort never even crossed my mind that it might not need one because of the controlable vains, can anyone help?

i know that sum cars dont even hav waste gates, help me please, time is of the essense, i need this car running by the end of the week cus my truck runs out of MOT :cry:

im so stressed, and then my pump decided to start leaking too :cry: :cry: :cry: :cry:

oldskool rich · « **Reply #1 on:** November 10, 2008, 05:58:28 pm »

sum progress

jimfoo · « **Reply #2 on:** November 10, 2008, 08:25:26 pm »

No, a VNT doesn't need a wastegate as long as you have proper control of the vanes.

Tintin · « **Reply #3 on:** November 11, 2008, 06:49:22 am »

Dont know for sure, but if you convert the turbo into a wastegated one, you will not be able to make spool the turbo properly, the design is not built to run with wastegate.

oldskool rich · « **Reply #4 on:** November 11, 2008, 06:28:28 pm »

thanx guys, thats all i needed to know :wink:

jtanguay · « **Reply #5 on:** November 11, 2008, 08:23:14 pm »

i think some people have added wastegates with some success, but as stated above using the vanes is the way to go.

Tintin · « **Reply #6 on:** November 12, 2008, 07:34:25 am »

Maybee if someone stick the vanes permanently in the middle position, it could control the boost with an external wastegate.

shortysclimbin · « **Reply #7 on:** November 12, 2008, 03:14:01 pm »

you could stick the vanes in any point to get the turbo to spool differently. Overall rule of thumb for vnt turbos is to use the vnt mechanism to control it. I have an Idea that with dual or really large vnt turbos that at really high rpms an EMP bleed would be nice to keep the turbo spooled up and no choking. I have yet to find an engine in the usa that needs this though. You would also need to first find out how much you would need to bleed and at what rpm to do so.

PS if you use just gt22 it could be both a wastegated turbo or vnt unit. your best bet is to use the full wordings like "gt2256v, gt2360v, (both vnts) or gt2260 wastegated..."

oldskool rich · « **Reply #8 on:** November 12, 2008, 06:00:57 pm »

sorry my bad, it not gt22, its a gt2052

i got confused with my other car :roll:

diesel central say that if you keep ur vnt closed for max boost too often that the turbo wont last very long

Tintin · « **Reply #9 on:** November 13, 2008, 07:13:21 am »

Thats normal, if you keep completely close the VNT vanes, you will get a lots of turbo surge at low rpm, probably 35psi boost and up at mid range and very very very high EMP, especially at high rpm.

The best is to stay the vanne just close enough to reach 30psi when you reach 4000rpm, and with the help of the wastegate you bleed for 26-27psi.

I think it's more easy to simply operate properly the vannes.

oldskool rich · « **Reply #10 on:** November 13, 2008, 05:19:12 pm »

well my plan was to have the vains operated by the throttle, so wen i accelerate they close up until it hits about 30psi and then i will use a waste gate pump to open the vains at 30 psi so that it will hold the pressure all the way through the revs

sound like a plan?