So has anyone nailed down the specific failure point of the EA888.3? Assuming you have a turbo that continues to flow efficiently and the supporting mods to run it, what's keeping you from revving to 8k, or 8.5k, or even higher? I've been searching for the last half hour but haven't found anything.
7
EA888 rev limit
- Thread starter The Dude
- Start date
jimlloyd40
Autocross Champion
- Location
- Phoenix
- Car(s)
- 2018 SE DSG
The EA888.3 engine simply wasn't designed to rev that high. I've seen a few guys say they rev to 7500 RPM. Mine shifts at 7000.
I understand that, but I was pondering the specific reason. Valve springs? HPFP gonna pop? All available turbos run out of air past 7500?
jimlloyd40
Autocross Champion
- Location
- Phoenix
- Car(s)
- 2018 SE DSG
Valve springs and whatever other parts are necessary to rev that high. And if it could rev that high someone would build a turbo that would flow at that RPM. It would be laggy at low RPM's . A lot of the foreign exotic cars like Lamborghini, Ferrari etc rev that high but they have no low end torque. A very high revving engine isn't practical for street driving. A friend of mine used to have a Honda Prelude and that car revved over 7500 RPM but you had to keep it above 4500 RPM to have any power. It was fun to wind it out though. Had a little bit of Indy car sound at high RPM and the trans was a close ratio one that would keep it in the high RPM range.
Escape Hatch
Autocross Champion
- Location
- USA
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- Mk7 GTI
It is an intriguing question and I am curious to know the answer. Current fuel cutoff for me is 7250 and I make power all the way up to that point. I'm sure these larger turbos can carry the power a bit further but the valve springs likely are not up to task. Perhaps a valve train upgrade with a port and polish?
JerseyDrew77
Autocross Champion
- Location
- Virginia & NC
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- 2016 TR GTI S 6MT
Running it that high you risk valve float which can destroy your engine. The highest I've taken my stock block is 7400.
roystr
Ready to race!
- Location
- California
"Undersquare" (small bore + long stroke) engines typically don't like to rev as high as oversquare engines (big bore + shorter stroke). The EA888 is significantly undersquare.
There's more side load on the cylinder wall vs oversquare. There are exceptions, of course. The 1.8 liter B18C5 in the Integra Type R is undersquare (but not as much as the EA888) and revs to 8400 and they run forever. The F20C in the Honda S2000 is oversquare and revs to 9000 rpm.
Plus, I think from a design perspective, it was setup with cams and a cylinder head that was optimized for lower revs and a turbo.
There's more side load on the cylinder wall vs oversquare. There are exceptions, of course. The 1.8 liter B18C5 in the Integra Type R is undersquare (but not as much as the EA888) and revs to 8400 and they run forever. The F20C in the Honda S2000 is oversquare and revs to 9000 rpm.
Plus, I think from a design perspective, it was setup with cams and a cylinder head that was optimized for lower revs and a turbo.
It is more of a DI comuter engine design limitation with the waterjacketed exhaustmanifold limiting flow.
The 1.8t 20v loves to rev to 9000rpm+ when built with our bore and stroke for example.
Honda S2000 in a nutshell. NA and 7000 rpm was its powerband. Constantly felt like I was going to blow the engine
JerseyDrew77
Autocross Champion
- Location
- Virginia & NC
- Car(s)
- 2016 TR GTI S 6MT
What are you saying? Stock valve springs or aftermarket? You would buy the kit which is valve springs and retainers and that will allow you to rev high.
With aftefmarket springs and keepers
JerseyDrew77
Autocross Champion
- Location
- Virginia & NC
- Car(s)
- 2016 TR GTI S 6MT
Keepers, there really isn't that many aftermarket ones to choose from. You have Supertech and TRW, which is OEM. I went with TRW because what you really need are the upgraded valve springs and retainers, in order to rev high and not get valve float.