JLT Big Air for Roush TVS install help

[QTR]

Hi guys,

I installed the intake on my car along with an off road X. I updated the tune, the old tune was from JDM and the new tune from a reputable tuner here. It feels really sluggish and gutless, way slower than before.

I datalogged the car as best as I can. It wasn't easy since it was surging and wouldn't let me rev smoothly, when you ease the throttle it feels like it's gonna stall, it doesn't though but it feels really weird and unresponsive. When you mash the gas for a WOT pull it hesitates for a second before shifting which is something it didn't do with the old tune. Also it's really unresponsive most of the time.

I had a shop do the JLT 123mm roush intake install and I wanna make sure they didn't **** it up. There are 2 hoses on the roush air box, on the JLT there's only 1 connection on the drivers side so he plugged the one that was on the yellow port here in this pic to the JLT port and the other one was plugged. I don't know if that's the correct way to do it or not. I just wanna eliminate the possibility of a bad install before I blame the tuner.

This is not a pic of my car, this is just to see if you guys can tell me where that other hose should be plugged or if it need to be omitted.

So, can you guys tell me if the other line was supposed to be plugged off or not. Because it has been plugged off by my installer.

I contacted Jay and he was really helpful. He said that the Roush SC should use that line and that I might have a leak. How do I check for that ?

I did not understand the instructions as they say "Plug in the PCV, Vacuum and MAF connections. If your set up does not utilize the vacuum port on the driver side of the tube, use the supplied plug to omit the fitting."

This is step 8 on the install instructions. Which can be found here.

Please let me know what I did wrong guys. The car feels like utter crap at the moment and I don't know whom to blame.

 

[WHITEMACH]

you have to drill a hole and hook up

 

[sambandit]

You definitely told the new tuner which CAI your were having installed, yes? The MAF curve on the CAI is totally different than the stock one.

 

[QTR]

My car is an auto yes. You hook the trans to the CAI ? I don't think I understand what you mean, I am completely new to all this. Please elaborate buddy.


Yes, I told the tuner which CAI I'm using, along with all the other mods.

 

[grnenvy]

How much boost are u running? Did u go with 82 or 85mm pulley first?

 

[WHITEMACH]

yes the auto has a different cold air from the factory than the stick shift!

 

[SILV03MustangGT]

thats got to be exactly whats wrong. I dont believe the JLT big air has a port for the trans kick down.

 

[QTR]

The car came with 90mm, I then upgraded to 82mm, CJ tb and JDM tune. Then I installed this JLT, off road X and the new tune.

Whitemach, I don't see that mentioned in the instructions, are you sure you're talking about the Roush supercharger CAI and not the regular one ?

 

[SILV03MustangGT]

The car came with 90mm, I then upgraded to 82mm, CJ tb and JDM tune. Then I installed this JLT, off road X and the new tune.

Whitemach, I don't see that mentioned in the instructions, are you sure you're talking about the Roush supercharger CAI and not the regular one ?

QTR I would email JLT. I dont think they offer the Big Air for an Auto car hence why there is no kickdown port to plug that line into. your're probably going to have to modify the CAI to hook that in.

 

[QTR]

How come this is not mentioned at all on their product page? You'd think something like this would be mentioned, right?

I just emailed them and will see what they say.

 

[WHITEMACH]

thats why in the above pic you see i modded my sound tube to fit mine.

 

[QTR]

But I see you don't have a roush supercharger, or do you mean that it applies to both?

Does anyone have the JLT installed on a Roush TVS A6 car? How should I connect this?

 

[WHITEMACH]

i was only told it was for the trans??????????

 

[SILV03MustangGT]

But I see you don't have a roush supercharger, or do you mean that it applies to both?

Does anyone have the JLT installed on a Roush TVS A6 car? How should I connect this?

you may have to drill into it, add a fitting and attach it.

 

[wbt]

Trans kickdown? Lol! This is not the 80's. The trans is electronically controlled. That port has nothing to do with the trans.

 

[QTR]

So, wbt, are you saying the installation is the same for both the A6 and M6 ?

I'm just trying to find out if I installed something wrong or not.

 

[SILV03MustangGT]

Trans kickdown? Lol! This is not the 80's. The trans is electronically controlled. That port has nothing to do with the trans.

so why is there a difference in CAIs for auto vs manual? I don't own an auto. What would his issue be then?

 

[wbt]

so why is there a difference in CAIs for auto vs manual? I don't own an auto. What would his issue be then?

Because Ford decided to use a different brake aspirator setup on the auto.

OP - locate your Roush install manual for the auto and you will find what that port is for. Also, do you have a pic where this line is supposed to plug into?

BTW - that CAI is a PITA to tune for. Based on what your are saying, the MAF signal isn't clean causing the car to use a different load value which impacts your shift schedules. Once the MAF curve is fixed, you will be back in business.

 

[SILV03MustangGT]

Because Ford decided to use a different brake aspirator setup on the auto.

OP - locate your Roush install manual for the auto and you will find what that port is for. Also, do you have a pic where this line is supposed to plug into?

BTW - that CAI is a PITA to tune for. Based on what your are saying, the MAF signal isn't clean causing the car to use a different load value which impacts your shift schedules. Once the MAF curve is fixed, you will be back in business.

interesting. I know Shaun said the new JLTs are alot better now, smoother interior and the screened filters have made a world of difference for tuning. (thats my car in the pic) that port is hooked up to the boost bypass IIRC. the roush install instructions said to leave the other port with the nipple on it alone. nothing hooked into it, so its probably the brake aspirator as you say it is.

 

[wbt]

interesting. I know Shaun said the new JLTs are alot better now, smoother interior and the screened filters have made a world of difference for tuning. (thats my car in the pic) that port is hooked up to the boost bypass IIRC. the roush install instructions said to leave the other port with the nipple on it alone. nothing hooked into it, so its probably the brake aspirator as you say it is.

I have all of this stuff sitting in my garage BNIB. If I had to guess, that plugged fitting on the Roush tube is for the vacuum booster. This can be eliminated by using a manual trans brake aspirator that is a direct replacement and replaces the non-check valve on the brake booster. I have no idea why Ford designed 2 different setups to achieve the same goal. I run a manual trans brake aspirator on my auto and it works great.

For the Big Air stuff yes it has helped however it is still a PITA to tune for. Goes back to having too much area producing turbulent airflow. If there was a better velocity stack design on the end of the tube, that would solve a good bit of that but I digress.

--Edit--
Found the link and it is what I thought it was:
http://www.roushperformance.com/par...r-Kit-with-Calibration-Automatic-10-10-11.pdf

This should have no affect on performance as-long-as there are not any loose ends disconnected.