Our Mk7 Volkswagen GTI now had a fresh suspension. What’s next? More horsepower!
And we know, we know: You’ve heard a million times that modern turbocharged cars can gain a huge performance bump from a simple tune. But it’s precisely that ease that has muddied the tuning waters in recent years.
See, if we stay true to our goal …
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I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Forte/1.6T gains with a tune alone are pretty impressive. Most net 30whp with a flash alone. Its insane
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
2023BD
New Reader
5/22/23 6:34 p.m.
Those are nice gains on the VW. These little turbo motors are fun with very little effort. The piggyback units you can buy for $300-500 are able to make big improvements in 15 minutes install time. Forte 1.6T went from 192-236hp at 6000rpm and torque went from 215-280 at 3500rpm (Dynojet numbers). All that just from tapping a button on a app, plugging into two sensors and filling up with 93 octane. These piggyback units don't even interfere with the ecu. I swore I would never buy a turbo car before the Forte GT but now I am hooked.
The 034 tune for the Audi B9 platform will be going on my 2018 S4. ECU and TCU.
Warranty is already gone, so the numbers are stupid compelling
Stock: 350 HP / 391 TQ
Stage 1 91: 397 HP / 491 TQ
Stage 1 93: 431 HP / 567 TQ
z31maniac said:
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
Agreed. That the best way to do it/ show actual gains.
ConiglioRampante said:
z31maniac said:
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
Agreed. That the best way to do it/ show actual gains.
Do more than one "after" test, though. I've seen modern cars that will show an initial power gain after being flashed, then they'll start learning around it and the gains go away. Vendors will usually chose to show the initial, atypical result but the real result is how the car works after it's stabilized.
Keith Tanner said:
ConiglioRampante said:
z31maniac said:
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
Agreed. That the best way to do it/ show actual gains.
Do more than one "after" test, though. I've seen modern cars that will show an initial power gain after being flashed, then they'll start learning around it and the gains go away. Vendors will usually chose to show the initial, atypical result but the real result is how the car works after it's stabilized.
Interesting. That's something I didn't know.
The Touareg responded well to a tune. +65 hp and +84 tq.
On the MK7 the stock IC is a huge bottleneck. And terribly inefficient.
For reference on track I was seeing consistent 120-130 IATs on a 78F day in my GTI.
A buddy with a Stage 1 APR Golf R was seeing so much timing pull at VIR that it was misfiring coming out of every corner. We threw my data logger in it and these were the results from a 15min session, ambient temp was 78F for reference:
With the intercooler added (APR) he's now seeing consistent 140mph at the end of the back straight, vs 130mph 2 laps+ in.
Does the transmission tune actually make vehicle emissions worse or is the lack of CARB approval just a paperwork thing?
In reply to CrashDummy :
That's exactly what the testing required for an EO is meant to prove, that it does not make the emissions worse. It is possible to get an "engineering evaluation" that will result in an EO, but only for certain classes of modification.
It is possible to go through the testing and not do the paperwork for an EO. That'll satisfy the EPA for other states. Kinda pointless, though.
You can't just wave hands and say "it won't have an effect" with testing or the third party evaluation though. So to answer your question, the answer is "it is not known".
In reply to flatlander937 :
Agreed; an upgraded intercooler is a "must" for track days.
Keith Tanner said:
ConiglioRampante said:
z31maniac said:
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
Agreed. That the best way to do it/ show actual gains.
Do more than one "after" test, though. I've seen modern cars that will show an initial power gain after being flashed, then they'll start learning around it and the gains go away. Vendors will usually chose to show the initial, atypical result but the real result is how the car works after it's stabilized.
This. The BMW motorcycle community learned this the hard way with those "booster plugs". On earlier bikes they worked fantastic by tricking the ECU into thinking the air temperature was colder than it was (or maybe I'm backwards). But after about 2005 the control strategy got more advanced and the ECU would calculate air temperature based on measurements from other sensors as well as measuring it directly. So when the measured value didn't agree with the calculated value it would declare the sensor bad and throw out its reading rendering the $80 plug useless. But they pulled like a freight train for a few miles.
To be clear, turning up the boost on a modern turbo car is almost definitely going to result in a power gain. Physics are on your side :) But the first dyno run after the tune may not be the most typical of the final result.
Opti
SuperDork
5/24/23 11:14 p.m.
In the same vein to what keith and flatlander said a buddy tuned an ecoboost mustang and said it ran great but IC would heatsoak quickly IATs would spike and itd be like stock in just a few miles.
A better intercooler completely changed the car after that.
We've documented pretty spectacular power drops in the Mazdaspeed Miata in stock form due to intercooler heat soak. I forget the exact numbers but it was double digit hp in 3 runs.
There are more updates coming about this. ;) But here's a teaser: The car is significantly faster on lap three with 100 octane vs. with 93 octane.
z31maniac said:
ConiglioRampante said:
I'm interested in seeing what the dyno shows. And yeah, usual disclaimer about dyno's differing from one manufacturer to another, are calibrated differently, altitude plays a role, as does ambient air temps & such. Still, it will be interesting to see some independent numbers...especially if the numbers are "at the wheels."
Should be pretty easy to dyno it stock, load up the tune, and dyno it again......same day, same dyno.
Air density changes constantly. Back to back will also change numbers. The second pull will be warmer than the first pull.
If we are looking at big differences. Fine! But a few horsepower? Too many variables for small differences to be valid.
More power seems like a good deal but is the additional power in the spot on the curve that helps or is meaningless?
I used to chase peak power and spent a lot of money in the pre computer era changing cams, heads mixture, timing. etc. to add another 20 horsepower. But since the gains typically were at PEAK RPM.'s my lap times either didn't improve or actually slowed down.
Then the variability of dyno pulls confused me. High air density pulls yielded gains that were based on weather. Not on actual improvements.
New chassis dynos help in that regard. EFI even more so.
wspohn
SuperDork
5/25/23 11:22 a.m.
People used to old cars that get X bhp from a specific power improver often get fussed when a modern car with torque calibration promptly learns down any power gain they temporarily got from an added mod. Probably feel that they lose anything but bragging rights about improving engine bay appearance
Retunes are mostly non approved by the powers that be, but some manufacturers indulged in it themselves. An untuned Ecotec turbo 2.0 gets 260 Tq and 260 bhp dead stock. Add money and tunes and you can get a very temporary bump that quickly learns back down to factory level. They issued a legal (IIRC, except in CA) factory retune that got you 290 bhp and 340 Tq (on manual trans cars) without changing any parts except the MAP sensors.
Interesting times when you can 'rent' that sort of bump up from some manufacturers . (see the other thread on that)
In reply to frenchyd :
Any good dyno operator can give repeatable numbers with a fairly small margin of error on sequential runs if the car is not suffering. The change in air pressure is basically irrelevant over that period. A dyno can be a very accurate tool if operated properly, and A-B testing is fairly straightforward.
This is a turbo car. We're not talking about a gain of 2 hp with a tune. The gains are not going to get lost in a small bit of noise.
You are absolutely right. In fact the dyno sheet should tell anyone if the gain is real or not. If the numbers on condition remain the same then the gains are real.
Yet if you do two back to back pulls. The second one will typically have more bottom end power and torque simply because the turbo is "up to temp" on the second pull.
In reply to frenchyd :
That last bit isn't true in a couple of ways. Turbochargers don't need to come "up to temp", and I can't imagine how a hot turbo would help torque. Probably the exact opposite as you'd be more likely to get detonation at torque peak.
But again, you need a good dyno operator who understands their equipment. Get the car fully warmed up, keep temps under control (as much as possible), eliminate as many variables as possible.