Where’s the torque?

[BFlat]

’87 Ltd. 39K miles. No speed parts. Replaced vac lines, plugs, ignition module, coil pack, IAC, trans & diff fluid, oil, waste gate, fuel filter & O2 sensor. Added Gen2 pump, hotwire, Scanmasetr, boost gauge, LT1 MAF & translator, TT chip for 91 with stock injectors. Car runs great. Just doesn’t have any real zip in the low end. It pulls okay once it gets going, and the boost gauge reads 15-16 lbs. Do a launch with brakes on & 4lbs. boost & the tires break loose for maybe 5 feet and then nothing. Acceleration is kinda “poochy”. Definitely not a tire-shredder. I don’t expect it to be a rocket ship, but something isn’t right. What to check? If there was an exhaust leak would it still be able to make 15 lbs. boost? Thanks.

 

[BRAD_PADGETT]

Check your valve springs. Put the car in third gear and floor it. Does RPM go above 5K on scanmaster?

 

[mblum]

Hows the transmission feel? Possibly slipping?

With an exhaust leak it will still hit those boost numbers, but the turbo won't feel very responsive.

Stock valve springs yet?

Still have the stock catalytic converter in the exhaust?

What are your O2 numbers at wide open?

Post up your scanmaster numbers with the engine warmed up and in park..

There's so many little things that can cause this. My WE4 has the same basic parts you listed, but does have exhaust and deleted cat. Its very responsive, much more so than my 86 GN that is way faster.

The stock turbo is quite good on a stock car. That is assuming the turbo is healthy.

 

[BFlat]

Thanks for stuff to check. I appreciate it. Tranny feels okay. Chirps tires pretty good on 1-2 shift. Probably stock springs, but only 39K verified miles on the car & it seems to keep pulling at the top end. Will do the RPM check Brad suggested (is that from a standing start or when it hits 3rd at WOT?) Dual exhaust with no CAT. One more thing to add to the mix: I get pops out of the exhaust when I let off the throttle. Nothing violent.

 

[BRAD_PADGETT]

Thanks for stuff to check. I appreciate it. Tranny feels okay. Chirps tires pretty good on 1-2 shift. Probably stock springs, but only 39K verified miles on the car & it seems to keep pulling at the top end. Will do the RPM check Brad suggested (is that from a standing start or when it hits 3rd at WOT?) Dual exhaust with no CAT. One more thing to add to the mix: I get pops out of the exhaust when I let off the throttle. Nothing violent.

Test springs at normal speed. The stock springs were garbage, and the valves float around 3900 rpm. This limits your power. My car with 33K milege had failed springs. Replaced springs with Comp 981 and the car woke up.

 

[GNVYUS 1]

Many possible things as listed above but...

Wastegate change?
Adjustable rod, base pressure 12psi or 15 (forgot the 2 number options).

You might need to confirm DP puck is seated flat and turn in the rod etc and/or ditch factory solenoid and go manual.
This is just 1 category of a possible issue here.

 

[BFlat]

GNVYUES 1; New waste gate. Not heavy duty. Rod backed off to approx. 1/8”. Still get 15 lbs. of boost.
Brad; How do I test valve springs at normal speed?

 

[TexasT]

Stock injectors probably need cleaned at the least, but If I'm pulling em out I'm going to a 42 or 60 and matching chip. As above valve springs are junk. Make sure you are getting the fuel pressure and it is rising with boost. I use a gauge taped to the windshield with a line to the end of the rail.

Next is some tires and a torque converter.
And if you are trying to put the exhaust through the stock cat you are wasting time. Gut it or test pipe.

 

[Pronto]

Weak valve springs...

 

[BFlat]

Stock injectors probably need cleaned at the least, but If I'm pulling em out I'm going to a 42 or 60 and matching chip. As above valve springs are junk. Make sure you are getting the fuel pressure and it is rising with boost. I use a gauge taped to the windshield with a line to the end of the rail.

Next is some tires and a torque converter.
And if you are trying to put the exhaust through the stock cat you are wasting time. Gut it or test pipe.

42's and chip are on next on my list, but not until I get what I have working. Unless the originals could be causing the popping when I let off the gas. Maybe they aren't closing? Thoughts?? No cat on the car. No need for stickier tires since it can't spin the new Coopers (those on the car when I got it were 24 years old) I have to break loose now. That's the rabbit I'm chasing. Thanks

 

[John Larkin]

Don't mess with 42s, go straight to 60s. It won't hurt at all and they are proven good. Unless you put a higher torque converter in the car to let the engine rev and spool the turbo down low, you are going to have lag. Pops out the exhaust is rich. Pops out the intake is lean. New chip and injs will fix that. Stock turbo won't need much converter, maybe a 2800 at most. As long as it is a lockup converter it will be perfectly streetable and easily reversable.

 

[TexasT]

If those injectors are stock they are 37 yrs old. They are tired and only flow 28lbs. This is not to say a 28lb injector isnt big enough, but they are tired and as stated need cleaned at the least. If you are buying new the 60lb are the way to go. This is a proven way. I went 42lb because I am cheap and bought them used with the matching tt chip for substantially less than new.

If that fuel filter is over a yr old it need replaced too. WIX 33481 HASTINGS / BALDWIN GF111 No telling what you have swimming around in the tank after this long either.

What abought plugs and wires? Brand, gap, and such? ohmed the wires? I gave up on autolite and have been using the ngk.