Too much lag and only 5psi of boost! Please help!!!
Yes, I pulled the air filter and put a plug on the inlet to the turbo. I did not find anything leaking on the turbo. I could only get up to 13psi and my plug would blow off 
.
As for the turbine, I do not know what the turbine wheel sepcs are. I bought the turbo from a member here. All I realy know is it is a GT-88 T-6 flange and the turbine housing is either a 1.06 or a 1.08 AR. I am going to get out there today and lift the car up and see if it has a data plate on it. I called Garett the other day and they had no idea what to tell me because I did have the info off of the data plate. When I get that i will post it here.
. As for the turbine, I do not know what the turbine wheel sepcs are. I bought the turbo from a member here. All I realy know is it is a GT-88 T-6 flange and the turbine housing is either a 1.06 or a 1.08 AR. I am going to get out there today and lift the car up and see if it has a data plate on it. I called Garett the other day and they had no idea what to tell me because I did have the info off of the data plate. When I get that i will post it here.
Ok, I could not find a tag on it like most garreatt turbos we use at work.
This is what I did find on it:
Turbine Housing; AR 1.08
Compressor Housing has several markings; AR .75, M=24 B.O. 1 Garrett U8408
Compressor Wheel has a ink stamp on it of 31
Center Section has two different stampings on it 12 and 4087
I dought any of this will mean anything except the 1.08 AR. I am going to try and contact the memeber I bought it from to see if he has any data from when he ordered it.
This is what I did find on it:
Turbine Housing; AR 1.08
Compressor Housing has several markings; AR .75, M=24 B.O. 1 Garrett U8408
Compressor Wheel has a ink stamp on it of 31
Center Section has two different stampings on it 12 and 4087
I dought any of this will mean anything except the 1.08 AR. I am going to try and contact the memeber I bought it from to see if he has any data from when he ordered it.
Stock manifolds, DIY cat delete wich was symply cutting the cats out of the factory piping and using @.5" exhaust pipe to replace them, from there it goes into a SLP 2.5" Y-pipe. Then it goes into a 3" mandrel bent I pipe over the axle to the turbine housing. The exhaust is heat wraped from the manifold all the way to the turbine inlet. From the turbine outlet it goes into a 5" wide radius mandrel bend exhaust pipe. Once the exhaust is pointing to the rear of the car it goes into two separete 3" exhaust pipes, the left side going straight out on the drivers side exhaust port and the right one goes over to the passenger side then straight out the passenger exhaust port. this section after the turbine is not wraped.
With the car loaded on the dyno and under boost we looked all over it and found no leaks in the exhaust. I did also pressure test the entire system as well.
With the car loaded on the dyno and under boost we looked all over it and found no leaks in the exhaust. I did also pressure test the entire system as well.
I did speak with the member that sold me the turbo. He told me who he bought it from. I will contact them tomorrow to get all the details on it. I will post the info here.
Ok, here are the specs on the turbo. It has a 88mm Inducer on the compressor wheel, the turbine is a 93mm and it is either a 56 or a 60 trim, it is supposed to flow 135 lbs/m. I talked with the supplier and they said they do rear mounted GT-88's all the time on smaller displacement engines like 370ci and they are building 15psi of boost by 4000rpm.
So I obviusly have a piping problem or maybe a camshaft issue. I am running a 230/240 .600/.600 114 cam. I do have the air filter off now, so if the weather holds out goo I will put the car back on the ground tonight and make a pass without the air filter to see if it is causing too mch restriction.
If that does not work I will test all the piping again.
Any one know what else I can do?
So I obviusly have a piping problem or maybe a camshaft issue. I am running a 230/240 .600/.600 114 cam. I do have the air filter off now, so if the weather holds out goo I will put the car back on the ground tonight and make a pass without the air filter to see if it is causing too mch restriction.
If that does not work I will test all the piping again.
Any one know what else I can do?
What kind of stall do you have in the car? Is it made for boost? One problem could be your just blowing throught the stall. I have a t6 flang and a gts78mm on a 4xx and have no issue making boost. I would look at the stall converter
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That unit has a 1.08A/R housing. We have several customers running these turbos on rearmounts and they are flying. Spool up is not a problem. Heck here is one with a 402ci motor and rear mounted.....
https://ls1tech.com/forums/forced-in...158-video.html
https://ls1tech.com/forums/forced-in...158-video.html
I bet you have a cold side leak. The method for testing the cold side that you used doesn't sound right. You have to have the air source on a regulator so that you can hold it at a steady, lets just say, 10 psi. You also need to open the throttle and check to make sure that you arent leaking out of the intake between the heads or around the injectors. How much vacuum at idle?
Sorry dude, did that, 13 psi regulated, pulled the intake rockers and pulled the air filter off and plugged it before the turbo. presurized the cold side from the turbo inlet to the intake valves, no leaks any were.
That unit has a 1.08A/R housing. We have several customers running these turbos on rearmounts and they are flying. Spool up is not a problem. Heck here is one with a 402ci motor and rear mounted.....
https://ls1tech.com/forums/forced-in...158-video.html
https://ls1tech.com/forums/forced-in...158-video.html
I have tried it from 11 to 19 degreees. I am wondering if I should switch to a revers split cam like 240/230 on a 117 or maybe the LS9 cam like Lingenfelter speced me. This cam I have was not intended for FI.
If your going to switch cams I would pick a cam that someone else has shown works in your combination. Eliminate as many variables as possible.