Garage Storage Organization and Garage Cabinets

ILIKESHELBYS · **How does a VNT perform when the 'V' quits working?**

I am wondering if a VNT car will exhibit turbo lag just like a regular turbo if the 'Variable' part of the turbo is not functioning. All the vacuum lines are hooked up BTW and I've gone through all solenoids, no fault codes either.

I have an 89 Shelby CSX VNT with 58K miles on it. For the last 5 years it has been driven a total of 150 miles and was not driven at all for about 2-3 years before I bought it. I also have a 90 VNT/CP Shadow that has a LOT more off-line pep than the CSX does. The CSX seems to have quite a bit of lag but once the turbo spools up and there is boost, she comes on good and hard at about 4,000 RPM. The Shadow has almost no lag but does not pull as hard on the top end. Seems like the performance for the cars should be more similar since they have virtually the same engine.

Is there any way to test for a dead variable NT....and if the variable part is frozen from sitting several years, can it be worked free with just a carefull disassembly/reassembly?

Thanks to all in advance.

**Will Martin** · 03-27-2005, 08:32 AM

How is your timing? My old '89 CSX #228 used to do what you're describing, along with overheating. Turned out to be a cracked head.

Is there a bigger turbo on there by chance? Like a TEC S60 VNT or a VNT 28? (I have both, and I've driven a S60 VNT car-little lag).

Or maybe a clogged cat.

So I'd first check the timing, double check all the lines, then the cat. I just recently (1 week ago) removed the exhaust housing off my S60 VNT to swap with a brand new one, and man was there carbon build up in there. You could see how the carbon was making the vanes stick a bit. When I moved the variable 'switch' with my hand, there was a bit of friction. On the new one, it moved smooth as silk.

ILIKESHELBYS · 03-28-2005, 11:22 PM

Yep, checked all that basic stuff. Timing as I recall was set at either 12 or 14 degrees advanced, no knocking and good power after the lag is overcome. It is a totally stock 58,000 mile CSX. No overheating, no smoke from tailpipe, no coolant in the oil. This car has no cat to clog so don't think that is it also great power in high RPMs so couln't be problem there. You did mention something I was curious about, opening the case and checking the movement of the vanes. I have two other rebuildable VNT turbos, one of which was brand new so it has all new vane assembly, dont know if I can just swap them or not. If I don't find an external problem I may open it up just to confirm that is not or is the problem. From experience, it might be better to just buy a new VNT outright rather than mess with trying to fix one myself.

**Will Martin** · 03-29-2005, 02:40 AM

Hmmm.......wow, sounds like you do have a hard one here. Okay, hows the clutch? I know it's a low mileage car, but are there any signs of the clutch slipping? Since you've checked all the other things off your list, then it's probably the turbo. Anyone else want to give a stab at this?

ILIKESHELBYS · 03-29-2005, 11:57 PM

Good clutch. I can dump it on dry pavement anytime if I rev it up a bit to get over the spool hump. Not a clutch thang'

steve911 · 04-07-2005, 08:46 PM

if the vanes are stuck wide open ther will be little boost and alot of lag as the vanes arent directing the exhaust at the proper angle and there will be alot of blow by across the vanes too. I believe you get the idea though.

Turbo Charger · 04-07-2005, 10:48 PM

Quote:

Originally Posted by ILIKESHELBYS

I am wondering if a VNT car will exhibit turbo lag just like a regular turbo if the 'Variable' part of the turbo is not functioning. All the vacuum lines are hooked up BTW and I've gone through all solenoids, no fault codes either.

I have an 89 Shelby CSX VNT with 58K miles on it. For the last 5 years it has been driven a total of 150 miles and was not driven at all for about 2-3 years before I bought it. I also have a 90 VNT/CP Shadow that has a LOT more off-line pep than the CSX does. The CSX seems to have quite a bit of lag but once the turbo spools up and there is boost, she comes on good and hard at about 4,000 RPM. The Shadow has almost no lag but does not pull as hard on the top end. Seems like the performance for the cars should be more similar since they have virtually the same engine.

Is there any way to test for a dead variable NT....and if the variable part is frozen from sitting several years, can it be worked free with just a carefull disassembly/reassembly?

Thanks to all in advance.

It's not the V that quits working..it's the 'T'.

Are you sure your Shadow is a VNT and not just a normal 2.5L Turbo 1? I guess you'd be able to tell by the tag on the bottom side of the hood. It would totally make sense if that was the case.

ILIKESHELBYS · **VNT seems to have too much lag**

Yes, I am quite sure the 90 is a VNT car, VIN# confirms it's 1 of only 27 Shadow VNT/CS cars built that year. The CS option was the same concept as the CS option on earlier Daytonas. Power nothing but a Turbo IV engine with stiffer shocks and rear disk brakes. It's a fun little ride, a lot like the 89 CSX/VNT but does not handle as well.

steve911 · 04-08-2005, 09:47 AM

Send me you phone number.... As a long term 89 CSX owner (2 in fact), I can probably explain it easier than I can write it.

steve911@charter.net

thanks
Steve A.

89 CSX 003
89 CSX 474

DirectConnection · 04-08-2005, 09:42 PM

If your *CAM* timing is right on, and you used the proper procedure for timing the base on your distributor, and you don't have a clogged cat, and your vacuum line sare on correctly and/or NOT leaking/cracked.... then I will say that your pnuematic vane controller is bad.

Have someone start the car up with your amr carefully behind the intake manifold and touching the lever/actuator arm and see if it moves down. When the actuator sees vacuum at startup, it pulls the rod down which opens the vanes in the turbine. If it doesn't, then the car will run really horrible like mine did. Possibly your's is leaky and acting weird as the one I replaced it with years back acts real goofy when the engine has only been run/boosted for the first few times. (It's like an on/off switch)

DirectConnection · 04-08-2005, 09:49 PM

Quote:

Originally Posted by ILIKESHELBYS

Yes, I am quite sure the 90 is a VNT car, VIN# confirms it's 1 of only 27 Shadow VNT/CS cars built that year. The CS option was the same concept as the CS option on earlier Daytonas. Power nothing but a Turbo IV engine with stiffer shocks and rear disk brakes. It's a fun little ride, a lot like the 89 CSX/VNT but does not handle as well.

Where did you get those #s from? I ask, because it was I that contacted Chrysler a long time ago for them. They gave me a letter stating 30, but over the phone, the % I had based off total production 2 door P bodies came out to actually 27. Their computer shows 30 as that's what they entered.