long 5. Performance is down -> what to do???

'I'm having this problem... I installed the longer 5th gear (0.681 ratio) in my ALH Leon (with 216 injectors and a software tune, resulting in 165 hp). Now, instead of 181 km/h at 4000 rpm, it actually reaches 202 km/h. The goal of this modification was to utilize the 165 hp to achieve a higher top speed. However, it hasn't really worked out that way, as it's only slightly faster than before, and it struggles at lower RPMs (which I can live with), but also struggles above 4000 rpm. With 165 hp, I should be able to achieve a real top speed of 215-220 km/h at around 4300-4400 rpm, but it seems like I'm lacking power in that RPM range.' I have to mention that I still have the original ALH turbocharger, which still provides 1.2 bar of boost above 4000 rpm, but it's certainly working inefficiently and close to its limit. What can I do to achieve more power, especially in the higher RPM range? Would a larger turbocharger (like the one from the ASZ 130 PS PD-TDI) be sufficient, or would 11mm pump plungers be better? Alternatively, could the software be adjusted so that the 51mg/H injection rate isn't reduced starting at 3850 rpm, but is maintained up to approximately 4500 rpm? Currently, for example, at 4200 rpm, it only delivers about 45 mg/H. I actually didn't want to replace the injectors again... And it should ideally remain within a reasonable budget. Thank you in advance for your ideas!

In your tuning, the long 5th gear wasn't taken into account, right? Maybe you could make the torque limit a bit more generous at the top end, and install a larger turbocharger (e.g., a GT1749VA from an ASZ/AWX engine). It makes the engine much more responsive and works well up to 1.5 bar (provided the engine block and components, such as the head gasket and screws, can handle the pressure).

Keep in mind that your engine is designed to deliver its maximum performance at 4000 RPM, and if you don't reach 4000 RPM, you won't reach the maximum power (pmax). Take a look at the performance curve of any TDI engine. (You can find them on the websites of many tuners, including on eBay.)

SeatLeon wrote:

Would a larger turbocharger (the one from the ASZ 130 PS PD-TDI) be sufficient, or would an 11mm pump plunger be even better? Or can the software be adjusted so that the 51mg/H is not reduced starting at 3850 rpm, but is maintained until approximately 4500 rpm? Now, for example, at 4200 rpm, it only releases about 45 mg/H. . .

Hi.

just a side note:
A 4-cylinder TDI engine producing 165 horsepower cannot achieve 4000 rpm with an injection rate of 51 mg/stroke.
The BPX already produces 57.5 mg of particulate matter at its (nominal) 160 horsepower at 3750 rpm, if I recall correctly.

The actual Pmax value you achieve therefore also depends on how much your tuner has modified the pump characteristic curve. And through that door, he can also give you more power at the top end (= more diesel), without VAGCOM showing even 1 mg more.

@ulf

So, I only read the 51 mg/H value using VAG Com, so I don't actually know the real injection amount. Do you think it would be sufficient to only modify the software as described above, or would you recommend a larger pump or piston?

What surprises me about the BPX is the fact that it reaches its maximum power (Pmax) at 3750 rpm, but its maximum speed (Vmax) is achieved at approximately 4350 rpm. This means that at that speed, there should still be a significant amount of power available... By the way, the BPX is only slightly shorter in its gearing compared to my current long 5th gear. 'Gang' is almost comparable.

SeatLeon wrote:

Do you think it would be sufficient to only modify the software mentioned above, or would you advise me to switch to a larger pump or piston?

Definitely a larger turbocharger; just that alone will free up a few horsepower at the top end.
I'm opting out of the piston pump project because I don't know enough about it.

Quote:

What surprises me about the BPX is the fact that it has its maximum power (Pmax) at 3750 rpm, but its maximum speed (Vmax) is reached at approximately 4350 rpm. Therefore, at this speed, there should still be a considerable amount of power available

.
The 6th. The design of the BPX's gearbox is, in my opinion, simply a flawed design when it comes to maximum speed.
The Ibiza forum has endless discussions about this, because no (single) Cupra TDI can actually reach the claimed top speed of 220 km/h, because the torque drops sharply above 4000 rpm, which is typical for TDI engines.

Your actual Pmax value therefore also depends on how much your tuner has modified the pump characteristic curve. And through that door, he can also give you more power at the top end (= more diesel), without VAGCOM showing even 1 mg more.

@ulf: It probably has to do with the fact that his EDC doesn't allow for more than 51 or 52mg max?! And maybe the tuner couldn't find the pump control unit, or didn't know what to do with it - it's not strictly necessary, though .

But a real 51mg dose at 1.2 bar is quite a lot.

Hi,

Just a random thought. I drive a tuned Volkswagen Golf III with a 1.9 TDI engine, producing approximately 130 horsepower. Last week, I also installed the longer 5th gear because I do a lot of highway driving, and the high RPMs were annoying (140 km/h - 3000 RPM / 160 km/h - 3500 RPM).

Although the software isn't optimized for the long 5th gear, the engine easily revs past 4000 RPM. The speedometer then shows something around 220 km/h or more. Before, the limit was around 210 km/h and 4600 RPM.

I can't entirely confirm the reported issues with the lower part of the vehicle. The only thing you need to be aware of is that you really need to rev the engine up to 2000 RPM in 4th gear, otherwise the connection won't work properly.

I think there might be something wrong with your car, because with that kind of power (even if it's only 150 horsepower), the long 5th gear shouldn't be causing any problems.



Sure, here's the translation:

'Best regards, bb'

Hi Bluebear,

Where did you get the number 5 from?
Have you found a good, affordable source?
Which one do you have: 0.70, 0.681, or something else?

I also want one because my Trekker stops working at 195.

m;

hi,

Well, unfortunately, I haven't found anything cheap either. I initially tried to find a complete transmission, but that was impossible and, even if I had, it would have been very expensive. I also contacted a transmission repair specialist, but he didn't have that particular gear pair in stock.

Okay, so I went to Volkswagen... there was no other option.

I got a value of 0.681. I calculated everything carefully beforehand, and I believe that the costs, effort, and benefits don't justify a value of 0.7.

I didn't want to go with a smaller sprocket, especially because I wasn't sure if it would still be compatible with the engine's power output, and because someone had mentioned that you might need to modify the shift fork with an even smaller sprocket.

but tell me, 195? how many RPMs does it reach then?? I need to use a GPS to find out what's really happening, but the problem is, I can't find a highway that's long enough and, most importantly, straight. damn mountains

You can still think about it, but if you decide to do it, I can definitely give you some tips.

Sure, here's the translation:

'Best regards, bb'

I drive a Golf III AFN, slightly tuned, with approximately 130 horsepower.
The software is not tuned for the long 5th gear, so the engine easily revs past 4000 RPM. The speedometer then shows something around 220 km/h .
(ANF 81kw BJ98)
I've never actually considered adding a fifth long hallway.
to have something built, because each time, this endeavor is immediately associated with...
was has been associated with significant costs.
If you could tell me more about your renovation, especially regarding the costs, that would be helpful.
The more detailed you are about the part number, the better I can understand what you're referring to.
make.

Perhaps this question isn't appropriate for this thread, or maybe it's already been asked elsewhere.
'has been discussed, and doesn't necessarily need to be answered, but it would be helpful to me if...'
I am very interested to know whether this gearbox/transmission component replacement (aside from the...
The replacement of the coupling cannot happen at the same time as the procurement of the HW components.
Since the transmission needs to be disassembled, and this results in a certain cost-saving effect?


Thank you in advance for your understanding & best regards.
Peter.

neubaupe wrote:

I would be very interested to know if this gearbox/transmission component replacement (aside from the hardware procurement) could not be done at the same time as the clutch replacement. Since the transmission needs to be disassembled, and this results in a certain cost-saving effect?

Ideally, the clutch should be inspected whenever the transmission is removed (or you need to know its exact condition). If the transmission is already out, replacing the clutch is almost just a matter of labor costs. The labor cost for a clutch replacement is based on the cost of removing and installing the transmission in over 90% of cases.

Depending on the condition of the clutch and the vehicle's mileage, it can be determined whether (and what) needs to be replaced.

Conversely, if you have a slipping clutch, you can use the opportunity to engage a long fifth gear. Install gang

Regarding the actual topic (5. I have nothing to say about that.

I don't know how it is with Seat, but with my Golf, I didn't need to remove the entire transmission. I just had to take off the cover that's on the back of the transmission, and behind that is the 5th gear. That's all there is to it.

Price: 185 EUR. Part numbers can be found here in the forum.

roughly speaking:

- Place the bowl under the gearbox.
- unscrew the cap (using a 11mm wrench)
- Collect the transmission fluid.
- Loosen the two Torx screws (Torx T60).
- Jack up the car and remove the front left wheel .
- Remove the shift fork (multi-tooth size 'eight').
- If the claw puller is too large (for a standard claw puller), then pull down the attached gear (very large) by hand. Be careful that the three parts, which are held by two retaining rings, do not fall out. Pay close attention to how the parts fit together. Once you understand how it goes together, you can simply reassemble it. Everything fell apart for me too, but it all became clear how it fits together. This is to remove the pressed-on gear with the puller.
- Simply pull the gears down from the two shafts (by hand).
-and put everything back together.
- Fill and top up the gearbox oil (17 mm Allen key).

Unfortunately, I don't have any pictures, in case that's what you were going to ask .

Please find an overview and calculations attached.

Sure, here's the translation:

'Best regards, bb'

ONLY 185 EUROS???

Where did you get that for such a cheap price?

Can you please list the parts again, roughly?
2x gear
Synchronization ring.
Switch reluctance.
2 feathers.

That comes to over 300 euros.

m;

stop stop stop


I only meant the two gears when I said 185 euros. I didn't replace anything else... why should I replace the other parts?

Does the rest fit?

I thought that because of a different number of teeth, the entire gear would be different (with a different diameter), and therefore the synchronizing ring, etc., wouldn't fit.

We had a lot of fun messing with that T4, trying to give it a really long fifth gear.

No... everything fit perfectly again... we really only changed the gears.

I was also thinking about whether to replace the needle bearing right away... but it doesn't matter... I'll do it when it starts to whistle .

Did you have to replace all of that on the T4? That's strange, because those gears are from a T4 transmission. Well, I guess you don't have to understand it.

The gear itself is only different in diameter compared to the second gear, which also needs to be replaced.

Where the synchronizing ring is located, everything is still as it was before. At least, everything is working perfectly for me .