not what I expected, 13.42 et

[turbowrenchhead]

I thought for sure I would get into the twelves last weekend. I had run a 13.52 with no i/c earlier this summer when it was hotter out. Now I added the ford i/c and get no improvement. I think that higher boost levels and 110 octane it doesn't matter to the engine much that the intake charge is hot or cold. I know the car is alot stronger in the lower boost levels. I am wondering what the problem is. I still have the stock turbo and I know I need to upgrade. I am thinking a TA 54. Could this be the problem. The stocker just instant suppling enough air to the large i/c? I also have to get a larger fuel pump. I can't supply enough fuel at WOT. O2's are around 730 mv's. But I have to rebuild my motor fircst becuase I had too much knock over the summer and my rods bearings are s**t. Looking forward to yanking the motor for the 3rd time in 3 years.

 

[national84]

How much boost are you running on the stock turbo? Maybe that's the prob.

 

[crazygn]

My guess is the stock turbo wont feed her with the inter cooler , maybe the intercooler is a little big for the stock turbo.

When i put my sperco on with the stock turbo , not much more power there . But with the ta33 i got a big power gain.

you have a lot of mods maybe you need more air

 

[cool 84]

What was your mph before and after? What about boost level, timing, and knock retard?

The turbo was the last mod I did and it was an unbelievable difference. I've said before that I belive the stock turbo is maxed out ~105mph.

 

[national84]

I haven't had any personal experience with maxing out a stocker, but have been told that it kinda feels like worn out valve springs. Huffin and puffin, but no go.

 

[turbowrenchhead]

I ran 20 pds of boost before and after the i/c. My mph is 98, that did not change either. The only thing that change was my 60 ft time. I could only get a 1.9 before, last sunday I got a 1.77. That is when I had my best time. I had the same 25 degree timing chip. I had relatively the same knock. I would always get 2 degrees at the end of the track if I kept it in 3rd. But if I let it shift into overdrive I won't get any. I also had my best run when I let it shift into overdrive. It is really screaming if I leave it in 3rd. I'd be willing I will see 12's if I put a bigger turbo on it. Just not made out of money. Plus I have to rebuild the motor again before I do anything.

 

[JDEstill]

Now that you are intercooled you definitely need more turbo...

You say you are running 20 psi boost? Making some assumptions about your max rpm, volumetric efficiency, etc... before the IC you were probably pulling about 430 cfm of air into the turbo. Give or take. That's a SWAG, probably good to plus or minus 10% or so.

Now making all the same assumptions, but changing the air temperature going into the intake to about 125 deg F, you should be pulling 570 cfm. A huge jump, and probably a lot more than what the stock turbo can handle from what I understand. To get that same amount of air flow without the intercooler, you'd have to run well over 30 psi boost.

Not sure exactly what is happening to slow you down, it could be a number of things. My educated guess (and it is just a guess) is that your poor little turbine is working extra hard trying to supply the power to the compressor to move that air. It is probably choking your exhaust system (it'll need a lot of extra backpressure to help provide the power it needs), and the high backpressure is hurting your power. Not a good situation whatever the case.

Did you have to really crank down on the wastegate to get it to make that much boost?

My advice to you: since you are now intercooled, you should get a turbo similar to what your '86/'87 brethren use for a similar setup. You probably need something in the TE-44 range at least, maybe a TE-60. Or with the newer models, maybe a PT-51 or PT-52. Something like that. It won't be money wasted in your case.

John Estill

 

[turbowrenchhead]

I think your right on the money John.