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The mkiv Supra Owners Club

N/A power (auto)


Toytown

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No not another "should I buy one" thread, I done that a year ago ;)

 

After reading various posts about the NA-T conversions, everybody seems to say that a standard N/A has a nice flat torque curve, which as I understand it, the car should pull well throughout it's rev range (3000 - 6000 ??)

 

My N/A Auto is the total opposite !

 

From 2000 - 4000 it feels a bit flat

 

4-5000 it wakes up considerably

 

5000 - 6500 it pulls really strong

 

The only way to make it go for it, is to bury the pedal & hold it there & when I do it can be quite impressive for a "lesser" model

 

Now it's got me wondering if there's something wrong, or if it has been messed around with ?? Doesn't feel *so* quick to me, but it's the only MK4 I have ever driven, so can't compare it.

 

What's YOUR N/A like ??

 

 

 

For the techies ........ this post got me wondering ....

Its a two-mode tuned plenum. Probably close to state of the art when the engine was designed.

 

Could it be that the valve on mine is stuck open or closed ?

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Thanks for the replies, but now it's bugging me :shrug:

 

 

That said, I got a WRX sorted last night (had all sorts of "engine check" problems), then took it out a few times on tests & thought it felt a bit flat -- asked my son to try it & he said it went well (same son that says my supra is flat).

 

 

Faye - NO mods whatsoever, I always thought it was a bit of a waste of time with an N/A ????

 

It's always surprised me that a 3L 24V with no turbo is such a "cammy" engine to drive, the best i can compare it to is a 16V GTE or Fiat Twin cam type power ....... like flicking a switch at 5000 rpm

 

I really don't want a noisy exhaust, I love the car just as it is (plain & simple), but is an induction kit a worthwhile option ?? I thought I had read on her etht mods on NA were for noisy effect only & that's really not my aim.

 

 

Could it be this valve thing that's the problem ?? :complain:

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  • 8 months later...

best mod u can do is a full decat and if you want it to fly use the manu button and change gear manually i have an apexi induction kit fully sheilded with two cold feeds on the filter .now ive done the decat it sounds great on full chat .

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best mod u can do is a full decat and if you want it to fly use the manu button and change gear manually i have an apexi induction kit fully sheilded with two cold feeds on the filter .now ive done the decat it sounds great on full chat .

 

what the "manu" button really do?????

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No not another "should I buy one" thread, I done that a year ago ;)

 

After reading various posts about the NA-T conversions, everybody seems to say that a standard N/A has a nice flat torque curve, which as I understand it, the car should pull well throughout it's rev range (3000 - 6000 ??)

 

My N/A Auto is the total opposite !

 

From 2000 - 4000 it feels a bit flat

 

4-5000 it wakes up considerably

 

5000 - 6500 it pulls really strong

 

The only way to make it go for it, is to bury the pedal & hold it there & when I do it can be quite impressive for a "lesser" model

 

Now it's got me wondering if there's something wrong, or if it has been messed around with ?? Doesn't feel *so* quick to me, but it's the only MK4 I have ever driven, so can't compare it.

 

What's YOUR N/A like ??

 

 

 

For the techies ........ this post got me wondering ....

 

 

Could it be that the valve on mine is stuck open or closed ?

 

 

 

Sorry anly just seen this. I woudl put money on it your Air intake control valve is either sticking or not working. Basically its a butterfly that opens at 4500rpm to let more air in for high rpm rev range, but below is shut to increase torque. It sits between teh V section of the intake manifold on your engine, you cant miss it.

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Sorry anly just seen this. I woudl put money on it your Air intake control valve is either sticking or not working. Basically its a butterfly that opens at 4500rpm to let more air in for high rpm rev range, but below is shut to increase torque. It sits between teh V section of the intake manifold on your engine, you cant miss it.

 

Its a distinct possibility. :)

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  • 1 month later...
Sorry anly just seen this. I woudl put money on it your Air intake control valve is either sticking or not working. Basically its a butterfly that opens at 4500rpm to let more air in for high rpm rev range, but below is shut to increase torque. It sits between teh V section of the intake manifold on your engine, you cant miss it.

Martin how would i know if this is sticking/not working cos mine is the same very flat below 5000rpm it feels a diff car in the mornings when first driving after warming it up at idle for 5mins very responsive and pulls well from 2500rpm??

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WOW.....Martin you may very be getting a big sloppy kiss on sunday:kiss:

Went and had a look at the butterfly valve and to my amazement there was a vac pipe just lying next to a steel vac pipe :idea: What if i connect them together and hey presto an na supe with power below 5000rpm :woot:

The kick at 5000rpm is not as violant anymore but only because i have power throughout the rev range.......RESULT

Gonna wait till the hks ti is fitted and then i may even keep it as its a completly different car to drive now

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Just got back from a bit of a run and cant believe how much difference a small vac pipe could do!!! Its a much nicer car to drive now,you dont have to ring its neck to get any performance out it,for some reason gear changes seem smoother now??:) :) :) :)

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Went and had a look at the butterfly valve and to my amazement there was a vac pipe just lying next to a steel vac pipe :idea: What if i connect them together and hey presto an na supe with power below 5000rpm

 

is it really obvious when you're looking for it then? i may take a look at mine just to see it all working as it should.

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Sorry anly just seen this. I woudl put money on it your Air intake control valve is either sticking or not working. Basically its a butterfly that opens at 4500rpm to let more air in for high rpm rev range, but below is shut to increase torque. It sits between teh V section of the intake manifold on your engine, you cant miss it.

 

Does anyone have a picture of this for the numpty's amongst us?

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