Top speed 95?

[Denny]

I was trying to push the SHO to 100+ last night and no matter how hard I tried I couldn't get past near 95. In third the car just had no balls after 80, then in forth around 90, then in fifth 95 was the best I could do? What's killing my top end? Fuel spark? 60K in need???

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1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[sdpatt]

You are missing at least 100 hp to not be able to break 95 mph. It takes more than an old timing belt to reduce the output by that much. Have you seen any CHECK ENGINE lights lately?


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Scott

1991, 254K miles, glass hood, police grill, SVO shifter, Catz fogs,
K&N, 73mm MAF, Superchip, PP Y-pipe, Borla cat-back, 190 lph pump
Eibach/Tokico/polyurethane, SHO Shop front & rear strut braces,
16x7.5" Moda R1, 225/55ZR16 Bridgestone RE730, -1 deg camber x 4,
Class II hitch, Silver award at the SHOklahoma Car Show

[This message has been edited by sdpatt (edited 01-13-2002).]

 

[RStalveyARFF]

WTF?? Ok, run the KOER test for the car, and follow the instructions of how to run a cylinder balance test. You have to be running on 4 cylinders or less, as when mine was on 5 I was cruising at 125 on the highway while spanking the crap outta a GAGT ram air(yes, 5 cylinders) That will spit out which cylinders are dead, and you can work from there.

 

[GaryH]

sounds to me like a seriously clogged cat or a really plugged up fuel filter if your car doesn't skip at idle then you are rinning on all 6 cylinders

 

[drivinhard]

I think if it was a fuel related problem, if it's that severe, then it would manifest itself in poor running even at low speeds/revs.

It's very possible (and common) to have a plugged cat, or cats in the yipe and to end up with this result. I've seen 2 SHO's do this. low end and mid range torque is good, but you loose all airflow above 5k or so and the car just makes no torque. I couldn't hit the rev limiter in 3rd gear in one SHO like this. Replacing the ypipe with a good one resulted in correct performance.

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White 92
SR71SHO - racer '89

 

[pjtoledo]

East lansing??? That's your problem, try running your SHO around Ann Arbor, it will run much better there!!!!!!
Perry Toledo,Ohio
Buckeye by birth, WOLVERINE by choice.

 

[Denny]

sd, yes I have had the light come on at three times since I've had the car, but they don't stay on permanently, I got the lean code from that.
SHO91MTX, cylinder test eh? I'd like to try that and see what happens
Gary, I'm looking at the fuel filter, have a new one purchased, just haven't had a place to be able to install it. I hope it's that. But I do hear some noises from the exhaust area, I think it's a loose heat shield though.
Drivin, well the only thing is about low end is that I'm having a frequent stalling problem if I don't use the gas pedal correctly. But you're right, low and mid feel awesome, especially when the secondaries open. But in the higher revs it just doesn't want to do it anymore in second or third.
PT ahahahahah lol! You really cracked me, well I was by AA today as I went to the Auto SHOw in Detriot.

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1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[Denny]

Sorry I meant to type PJ not PT!

------------------
1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[drivinhard]

"But I do hear some noises from the exhaust area, I think it's a loose heat shield though"

Get the pipe off there asap before you trash your motor, and check/replace that thing. "loose heat shield rattle" is classic sign for a trashed cat. Blip the gas, and listen for the rattle afterward (as the revs fall).

Take the pipe off and inspect, I'm going to bet it's the cats.

If you end up needing a good one I have a good used stock one for sale.



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White 92
SR71SHO - racer '89

 

[sdpatt]

The rattle in cats after blipping the throttle was the sound that tipped me off that the SHO Shop Y-pipe was about to choke off my engine. The loose heat shield sound is a tinny metallic rattle. The crumbling ceramic sound is more like rocks or marbles shaking around inside a tin can. My cats plugged so effectively that the engine wouldn't pull past 4,000 rpm in any gear.

Scott

 

[Denny]

Bad cats?!? EEEP! Uhhh if I just gut them off wouldn't that be a pretty quick and easy solution :-D with some hp too! Hehehe

------------------
1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[fredhurderjr]

I used a piece of metal conduit, bent at strategic areas to gut my old SHO-Shop unit off the 91. MAKE SURE YOU WEAR A MASK. The ceramic dust is a no-no with your lungs. Bad stuff, man. It is a time consuming process, and you can't count on passing an emissions inspection later on. If you pull the pipe & tip it upside down & sand comes out, that's probably your culprit. Good luck Denny.

 

[Denny]

Ok I tried testing for this blip? After I rev the only thin I really hear is like sputtering? It's like when you put your lips together and like plbtttt like that. Is that a blip?

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1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[Denny]

*bump*
So would a bad cat cuz a buzzing sound as the rpms drop?

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1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[Splitz]

not always, sometimes the exhaust will smell strange, oh and you should keep you cat they, if you have them removed you may make more HP but you'd lose torque

 

[93SHOCOOL]

That sucks I was having problems breaking 200mph the other day!! Just kidding I had the same problem and the fix was new plugs and wires, new fuel pump and fuel filter. (I am not sure which one was the fix, b/c i had them all done at once)

 

[Denny]

93, did your fuel pump whine and such before you replaced it? My pump doesn't make any unusual noises, but I bet the filter is the original one from 1990. Going to change that soon

------------------
1990 SHO
Stock

1992 3.8
16.9@81
RIP

 

[93SHOCOOL]

Denny, actually it just took a $hit! I was driving one day this past summer and it just quit. It never made any noises or gave me any warning. In my opinion replace the fuel pump before it goes bad if it is the original. (just a little FYI)

 

[Tommy the Greek]

Would'nt the engine shake when it runs only on 5 cylinders? I mean it would be noticable - right?

 

[Rich92forSHO]

I had a problem once on my 92. During the summer with the engine warm and crusing at higher than normal speeds, sometimes it would start to act like it was running out of gas it was stumbling and I tried getting errors codes out of it to no avail. It would also stall out on me at a stop especially with the a/c on. I tried to fix it by replacing the fuel filter to no avial and eventually just replaced the fuel pump. I haven't had a problem like that since.
So if you can't get and error code on it start thinking about the systems on the car not covered by computer control that could cause that problem.