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Discussion Starter · #1 ·
I just recently replaced my TCV and the vacuum lines that go to it. The main reason was to fix an overboosting issue, but I was also hoping it might improve the turbo performance a bit.

This is my first turbo car, so I'm not really familiar with what it's like. The turbo lag with this car seems excessive. If I'm cruising at around 2.5k RPM in third and I put the hammer down, there is a solid second before the turbo spools up and I actually get going. Even at higher RPMs it takes a long time for the turbo to spool when you roll on the gas.

Is this normal?
 

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Mine was like that too.

When I had the transmission out, I had a local shop restall the converter. Now it will flash up to 3700rpm, a little higher than I'd like but I don't feel like pulling it and trying again. Lag no longer exists, just insta-boost.
 

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Discussion Starter · #3 ·
I have noticed over the past few days that the boost does roll on a bit smoother and earlier than it did. I was just hoping for a lot better response. I guess I will just have to get a downpipe for it. Really twisting my arm here, car.
 

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It's a turbo. A relatively large turbo for the Volvo world. It lags. It's just physics. I find the lag more noticeable in advanced mode. How much you notice it depends on where you're coming from. I didn't think my R had any lag at all before getting an XC90 V8 and a Corvette. Now I notice it.
 

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The turbo lag shouldn't be super noticeably bad in the R. The VVT should take care of most of it.

But this is coming from me. I drove an 80s Garret turbo 740 for a first car. I was born in the lag.
 

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I have to say compared to some of the 80's turbos I've driven the R is almost non existent as far as lag.
I expected some but it really is pretty well sorted in that department, and thats also considering it's a 15 year old car so not even cutting edge anymore
 

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Non-existent lag until you experience the huge, overflowing, instant torque of a high output naturally aspirated engine. Certainly true that it does far better than 1980's first gen turbo cars, but that's probably not giving it enough credit. Let's put it this way, the lag is on par with a second gen S60 or current gen VW. Purely physics. The turbo has to spin to generate boost. The exhaust gasses take time to spin it up. The bigger the turbo the more noticeable. This is part of the reason that Volvo supercharges and turbocharges their current engines. The supercharger provides a more instant level of response.
 

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The K24 is larger than the K16 in the C30. I honestly feel that the C30 has more turbo lag.

I'm just saying that Volvo's claim of max torque around 2k rpm is pretty accurate
 

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All things being equal a larger turbo of similar design will lag more. The R is not equal. It has a different/better exhaust manifold. The turbo design may also have some advantages too (not sure). My main point is that physical things that need to spin take time to spin. That time is perceptible and that’s what people notice as lag. Even if the R is better than most/all/every other turbo car does not mean that it has no lag.
 

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All completely correct, and then there is the Audi electric supercharger which can activate full boost in something like 0.15 seconds.
I've not even done any digging on newer turbo designs as frankly mines a daily and I don't want to throw $10k at making it faster given that I barely get the chance to use 50% of what it has already.

I find it very driveable, and more accurately I personally don't find the lag noticeable - and I came from big bikes so know naturally aspirated high output fairly well (and I liked it)
 

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The K24 is larger than the K16 in the C30. I honestly feel that the C30 has more turbo lag.

I'm just saying that Volvo's claim of max torque around 2k rpm is pretty accurate
It is if you wait long enough.

The K24-7400 is actually a little bigger than some K26s, if I recall right.

If you want lag, try an old no-compression Audi 2.1l with a K26.
 

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It doesn't bother me much either. Otherwise the car would be gone.

I had the misfortune of driving a Ford Fusion Hybrid. This was the laggiest car I have ever driven. You'd think that the electric motor would give instant response but this wasn't the case. When pulling out from an intersection I floored the thing and it just sat there for a second before doing anything. Scary and dangerous.
 

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I have noticed over the past few days that the boost does roll on a bit smoother and earlier than it did. I was just hoping for a lot better response. I guess I will just have to get a downpipe for it. Really twisting my arm here, car.
Do you have an automatic? My VR is stock. Reset your car, train your transmission on your driving habit and use the manual shift in your automatic.

When I go into corners I will put in manual, check the RPM’s, downshift, and punch it and then to next gear half way thru the turn. If you feel resistance and bogging, lay off the gas and let the car roll to 2k. Don’t touch gas and Then hit the gas lightly to adjust for the turbo and accelerate . When it kicks in punch it slowly, while you feel the engine pull. Play with the peddle for max acceleration. Keep doing this. Your car will then learn that you like to drive at a higher rpm.

This works. MY10c70t5 also goes into corners now in 2nd to 3rd with no lag. Instant change to 3rd.

Continue till you feel the car pulling in second gear and when third kicks in drop off the pedal quickly and wait for third to kick in. Remember 1st&2nd are restricted. Now punch it slowly till you feel the turbo spool and launch the car. Make sure you have good brakes. You’ll hit 60 before you know it.

Don’t drive your car hard all the time. Occasional do punch it so when the time comes the car will go. Just warm it up first.

I do live in PA with lots of hills and curves.


Sent from my iPhone using Tapatalk
 

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I had the misfortune of driving a Ford Fusion Hybrid. This was the laggiest car I have ever driven. You'd think that the electric motor would give instant response but this wasn't the case. When pulling out from an intersection I floored the thing and it just sat there for a second before doing anything. Scary and dangerous.
Interesting, I wonder if that is some sort of weird Ford thing. I had a '95 Ford Thunderbird 4.6 V-8 that took a full second to second and a half to downshift and go when I floored it. Very dangerous in traffic, especially on the highway. I found a paper by a Ford transmission engineer on how to reprogram the trans and that made it very enjoyable (and much safer) to drive.
 
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