totally stock 87gn with ta-49 boosting slow

buickshake87

Member
Joined
Sep 25, 2010
I have just installed a TA-49 turbo on a totally stock 87 grand national. It boost's much different than when the stock one was on. I'm not sure why or if this is a normal thing but I felt like I had a much stronger boost with my factory turbo. Can't get the new turbo over 11 or 12 lbs of boost standing on the floorboard... any help would be awesome, thanks homies...hahaah
 
First thing to do is double check for exhaust leaks and vacuum leaks, and make sure you reconnected the vacuum lines correctly.
 
Is the puck lined up on the turbo? maybe the accuator lines are backwards?the y is smaller on one side.
 
I believe the lines are on correctly and this came off another buick that only used it for about 5k miles. I will check Y vacuum lines. Just wondering what holds back boost cause seems like the turbo is harder to get spooled than other 1 and stops at 12. Like its governed by something. I'm completely new to turbos might I add.
 
I believe the lines are on correctly and this came off another buick that only used it for about 5k miles. I will check Y vacuum lines. Just wondering what holds back boost cause seems like the turbo is harder to get spooled than other 1 and stops at 12. Like its governed by something. I'm completely new to turbos might I add.

Did your 49 come with its own wategate actuator or did you use the old one off of the stock turbo??

BTW: 12 psi is the stock boost level for these cars, with a non adjustable wastegate, etc..
 
Slow Spoolin TA-49

What exhaust housing do you have....Garrett or Precision?

Reason I'm asking is that the Garrett .63 Exh Hsg will spool much more quickly with a stock D-5 Convertor than the Precision.

You may find that you'll need to change over your convertor to one with a higher stall....say mabye a 10" - 2800 stall to spool the Precision quickly.

Also, as others have suggested...make sure you have no exhaust leaks or vacuum leaks as this will also kill your spooling.

Ensure that your waste gate puck is sealing the exh housing properly too.
 
Is the CAT gone .if not and it is not a high flow cat that will make a 49 feel very sluggish
 
Cool thanks guys, I spoke with the guy in my area that's pretty good with these cars and he said that there are many variables that can cause my boost to be a little slower. Also they are gonna help me adjust this. Thanks for the reply's and ideas. This site rocks cause of good people
 
turbo

Did you have a new chip burned for that turbo? or have a adjustable chip already in the car now for fuel and timing.that will also make a difference.
 
No chip but seriously considering it. Just wanna make this car able to be little over stock dependable driver cause I love driving it. The suggestions from my buddy where- hotwire kit, upgrade fuel pump, injectors, adjustable fuel regulator and wastegate, probably exhaust and intake then burn the chip to those specs. Maybe I can come into 1 million dollars and really blow the motor right :)
 
the list

Oh " the list" lol! It's never ending. There is never enough money or it's not fast enough.I've had three 1gn 2 T's.and I still haven't learned to leave them alone.every year the motor,trans or something has to come apart or be removed, to be improved upon. I guess that's what winter is for can't drive them take them apart. Sorry it must be a Buick thing!
 
You need to figure out whos TA 49 turbo you have.....example the ones we sell use the stock Garrett exhaust so low end torque is not lost. Some of the others use a different exhaust housing and on normal street useage low end torque may not be as strong as it was. For race applications it may be great

That is why we have a core charge as we need original turbos in order to use the original exhaust housing so low end torque is not lost.

denniskirban@yahoo.com

in other words not every TA49 turbo is the same.

While all the above advice is good, you need to figure out who made the turbo you have.
You can do other modifications to overcome the loss torque you are experiencing if indeed the issue is related to the turbo. I don't want to give the impression the one we sell is better only that the one we sell does not require any other upgrades in order to maintain the low end torque aspect.
 
Thanks guys. Dennis, I'm not sure who built my turbo but a good friend bought it for his basically stock GN. Wasn't enough and he sent the car off to Cotton to build. The exhaust housing says Precision on it and I still have my factory garret 1. Sounds like I need to swap them over from this advise. I'm very happy with the power just want that low end back. I did find that I had so many vacume leaks that it was causing my old turbo to overboost constantly. I could get 15+lbs at half throttle then it would start knocking. Guys around here said I'm lucky I didn't blow the motor already. I didn't know any difference, thought that's how they ran. Got the car 6 months ago when Dad died and poor guy didn't fix anything haha. He would be happy now. Thank you.
 
Is that Jay's old turbo? Precision housing you are probly looking at a new convertor may be cheeper then getting the housing changed I may be wrong but I think the stock one needs to be modifed to use it.
 
I have just installed a TA-49 turbo on a totally stock 87 grand national. It boost's much different than when the stock one was on. I'm not sure why or if this is a normal thing but I felt like I had a much stronger boost with my factory turbo. Can't get the new turbo over 11 or 12 lbs of boost standing on the floorboard... any help would be awesome, thanks homies...hahaah

the same thing happened to me when i went from a stock turbo to a ta49. the wastegate hole was larger than the stock puck and had to get a 3 inch downpipe. take off your elbow and measure the hole and the puck
 
If you have a Precision housing, you do need to do other upgrades to recapture the low end torque your car once had.

I do not know for certain if switching the stock exhaust housing into a Precision TA49 will work as far as everything fitting properly.

This is something you would have to check with Precision or as others have suggested make other upgrades to regain loss low end torque.

The TA49s we sell utlitize the stock exhaust housing so they do not need additional upgrades to retain the low end torque.

denniskirban@yahoo.com

Obviously fixing any other problems such as vacuum leaks etc will get you more improvements.
 
No chip but seriously considering it. Just wanna make this car able to be little over stock dependable driver cause I love driving it. The suggestions from my buddy where- hotwire kit, upgrade fuel pump, injectors, adjustable fuel regulator and wastegate, probably exhaust and intake then burn the chip to those specs. Maybe I can come into 1 million dollars and really blow the motor right :)

First mod should be a scantool to verify everything is setup properly. Scanmaster2.1 will do this. Use the search button.

Slower spool is because wheels inside the turbo are larger, lower boost more than likely has to do with your actuator.

Finally.. if the exhuast housing is a Precision piece, then you'll need a looser stall converter. If not it will feel very sluggish until it gets over 5 PSI boost.
 
Yeah that's Jays old turbo. Thanks guys. Wish there was some way I could help you guys. Maybe just post a picture of me burning the tires off after upgrades will be sufficient:)
 
Oh also, what fuel pump are you guys running? I've heard mixed opinions on brands. I don't plan on having the car modded much more. Just want my torque back out of this turbo and then it could possibly be a daily driver not that I wanna rack up the miles but I'm never selling it so miles aren't a factor to me. Was my Dads and that's why I won't part with it. Anyway guys thank you very much for your help.
 
I need to get over there and see jays car Im going to be in the buro for the holidays. I wondered What he did with his extra parts. Most guys are running a Walbro and Alky Im running e-85 so im doing something a little diffrent.
 
Top