So long story short I built a 9.5 compression, truck manifold setup. I used a t4 1.32ar comp ball bearing billet wheel 80/79. Put it on the dyno at speed inc and it had 4:1 back pressure.

Comp has helped out alot and have stood behind their product. I sent that one back, they replaced the compressor wheel with an updated one. I put it back on yesterday and can already see a huge differance.

Before it could only do 11psi due to high back pressure. Now on the street spinning the tires it hit 18psi no problem with an almost instant spool.

I'm set up in the beginning of january for a retune and il post back up. But so far so good, and it sounds like a rocket in boost, shut the car off and it spins for about 30 secs after.

Alex

 

Thanks for sharing the intial results. I know a few are following the Comp updates........

Why would they change the compressor wheel if it was backpressure that was holding you back? Or did you mean the exhaust turbine wheel was replaced??

 

Honestly I had the same question. I kinda trusted them on this one even though it didnt make much sense that the compressor wheel would help. Maybe they did update the turbine also and didnt want to tell me for some reason. All i know is that what ever they did in there helped, alot. They dyno will be the first real test.

 

This doesn't make any sense. Was the bearing assembly in the old turbo tight?

 

Im going to send him an email to find out exactly what was done just out of curiosity. Bottem line is if you order a 80/79 now it will be the updated one.

 

What is the 80/79? What are the specs on the turbine wheel?

Does the 80 part mean an 80mm inducer on the comp wheel and then the 79 means 79mm exducer on the turbine wheel? Because 79mm on the turbine wheel is pretty small if the comp wheel is an 80mm inducer.

For example, my BW has a comp inducer of 75mm with an exducer on the turbine wheel of 83mm. Lots of guys here consider that hot side to be too small for that setup. 80mm comp wheel with 79mm turbine would be even worse.

EDIT: Just got done looking on Bullseye's website. They say my turbine exducer is 83mm but the inducer is 74mm. Everyone knows that on a turbine wheel the exducer is smaller than the inducer. But that's how they have it listed... Oh well.

 

It is a 100 trim turbine (isnt it?) so it cant be compared to other turbines

 

It is a 100 trim

 

80 mm compressor wheel 79mm turbine wheel, 100 trim.

 

I have two of these, older 8079 & new 7679, best street turbos out there for the money and physical size. I knew there was something wrong with the turbo you had IE: bad bearing or something.

 

my money is still on a bad bearing in the turbo, but its good they took care of the problem.

 

Code4, what did you have the 80/79 on? Any dyno or track times?

 

I agree! I have been selling Comp Turbos since they opened the doors and they have always provided great customer service.

 

I thought they upgraded you to an 88mm turbo? Something had to have been up with your old turbo.

 

They did but it was physically too big and not water cooled so I sent it back. It was a badass piece

 

Just did a couple highway runs. With the 11psi spring it did 10psi spinning the tires at 65mph. I'm thinking my back pressure issue is fixed. Can't wait for the dyno.

 

What did they do?
I have an 8079 already and it's going on a 6.0 also so I'd like to know what they did if anything for when I call. They may have just put the cast compressor wheel back on it.