Torque Gone And Want It Back

Skyhawk_au · 02-08-2005, 05:22 PM

I have not posted in awhile. Over the holidays I had about $2200 worth of work on my car. List of repairs is long and there were no mods done. The gist is the engine was completly resealed, new clutch, exhaust leak fixed and other things where done b/c the engine was out.

As for the torque. I gutted the cat. My 93 t is stock. I do know that opening up the exhaust does affect the torque curve. I was going to put down pipe on it but am affraid o decrese the back preasure anymore and want performance gains. So how do i get torque back without replacing my cat.

Would ading more boost help I thought about anding a controler at this point.
Need some help what do you guys think.

JekylandHyde · 02-08-2005, 07:15 PM

Turbo cars love open exhausts.
Did you properly break in your new clutch?

MR2Driver · 02-08-2005, 07:43 PM

1st time i've heard of someone against a open exhaust

Im JDM Yo · 02-08-2005, 09:07 PM

I hear this argument all the time. "Turbocharged vehicles love backpressure because it makes torque" and "Turbocharged vehicles love the widest, straight exhaust possible because its forced induction, and it makes HP and TQ"

Im still to this day confused.

Skyhawk_au · 02-08-2005, 09:23 PM

First I appreciate the responses. I am not saying I don't like open exhaust. and am not quite sure where that came from. I was told that opening your exhaust without any other mod will change the torque curve on the low end but does increase increase hosepower at higher rpms. This information was presented by reputable individuals in the MR2 community. gutting the cat in my case, the info has proven true. I just want my lower end torque back without losing the gained upper end horsepower and am asking te best way to MOD my relatively stock MR2 to achieve my performance goal.
As for my clutch . I did drive easy for the first 100 or so miles but there was litle instuction on the "proper" way to break it in. not to divert from the question at hand what is the proper way.

JekylandHyde · 02-08-2005, 10:17 PM

Generally the proper way to break a clutch in is 500 mile of city driving ~ lots of "normal" shifting, nothing harsh.

Opening up the exhaust and not tuning for it, can cause you to lose a bit of low end. However, if you tune your car for an open exhaust, that would be ideal on a boosted car.

You said you fixed an exhaust leak ... then you should have gotten torque BACK.

Something does not sound right to me.

Skyhawk_au · 02-09-2005, 01:01 AM

I don't know if you remember or not it has been awhile. But I had an exhaust leak. While fixing that problem I gutted the cat therefore loose the low end which I want to get back without putting the cat back on. Yes I did loose boost during the leak period but now that it is fixed. I have noticed the torque loss due to the gutting. The leak was professionally fixed as with all the work. knew cap rotor and wires were installed aswell all were toyota. The car runs good with strong upper end but sluggish on the low. What is the best way to get a good full range of torque and power.

JekylandHyde · 02-09-2005, 08:36 AM

I have been playing the MR2 game for 15 years and I have talked to a lot of people that have gutted cats and I have never heard of one of them losing low end torque to any significant degree.

The only time I have experienced that was in the NA, which will have a more dramatic affect.

If you have a significant loss of low-end, I really think it is something else. That's just my $.02.

Skyhawk_au · 02-09-2005, 10:40 AM

Thanks Jeff, I had alot of work done but nothing that I thought would give a DECREASE in performance. I will take is back and maybe get it dynoed. There is a harmonic in the engine when it transitions through 4-5 k RPM. It shakes the petals and shifter a little. It is subtle. I am used to engines running like sewing machines. It has 128k on it so maybe I am expecting to much. Thanks again for all responses.

JekylandHyde · 02-09-2005, 10:43 AM

... change from 4-5 k????

That is when the TVIS is suppose to open.
I would check your TVIS system.
If all 8 valves are getting air below 4500 rpms, you would suffer a loss of low end torque. That is what the system is for.

The fact that you have a sudden change around that sweet spot indicates there may be an issue there.

Skyhawk_au · 02-09-2005, 10:52 AM

Well that sounds like a good start. Thanks again.
I have talked to a few of the guys at ATS before the holidays about the down that was in testing. I believe it was a three inch. Sorry i can't remember the name. I think I was talking to te owner of ATS. I was going to ship them my car from ATL to have some one that know my car but logistics where not practical.
Anyway, Is there knew down good for my stack ap or should i go with the 2 1/2 KO.

Im JDM Yo · 02-09-2005, 06:29 PM

What does TVIS stand for?

POST REPLY TO THIS THREAD