Don't buy an IS38...but should I?

[roystr]

One of the most common reasons people shun the IS38 these days is because there are a lot of good hybrid options that don't cost that much more.

A new IS38 can be had for $1250 from FCP Euro and ShopDAP. In the ~2k range, you have the EQT Vortex, the IHX475, the Littco L450, and (for a little more) the DBV2. All 4 of these turbos require a fuel system upgrade though and it seems like people are moving away from simply upgrading the HPFP and instead doing LPFP and MPI. That adds about $1300. So, you're looking at about 2.5x the cost vs an IS38 which can be run with E30 and "not ridiculous" boost and still make good (and hopefully) reliable power (say 380-400whp). I get it that you have to pay more to get more, but it seems like with these 4 turbos, you have to pay A LOT more and the $ per HP return is significantly worse.

Check my math?

 

[jimlloyd40]

Decide on your goals first. If you decide to go with an IS38 get the Littco L380 which is an IS38 with upgraded beaings and balancing for pretty much the same price as an OEM IS38. I believe EQT and TPC have similar ones also that don't cost too much more. You won't need upgraded fueling with any of those.

 

[Jovian]

Here is my opinion and why I’m sticking with the IS20. https://www.carworklog.com/2017/07/03/should-i-go-is38/

 

[Hoon]

IS38 has become very underrated. It's an exceptional daily setup, and to fully support bigger turbos gets a lot more expensive.

Many people will disagree, but all things considered a good IS38 setup is the sweet spot for a GTI. Cost effective, quick and reliable.

 

[jimlloyd40]

Here is my opinion and why I’m sticking with the IS20. https://www.carworklog.com/2017/07/03/should-i-go-is38/

IS38 has become very underrated. It's an exceptional daily setup, and to fully support bigger turbos gets a lot more expensive.

Many people will disagree, but all things considered a good IS38 setup is the sweet spot for a GTI. Cost effective, quick and reliable.

Completely agree with Hoon. That's what I have. And that link that was posted is typical of the reason people say to stick with the IS20. Properly tuned it's not true. My IS38 would blow away my IS20 that I replaced 0-60 and that's supposed to be where the IS20 has an advantage. Sure the peak torque is about 500 RPM higher but where the IS20 peaks my IS38 already has more torque.

 

[Jovian]

Completely agree with Hoon. That's what I have. And that link that was posted is typical of the reason people say to stick with the IS20. Properly tuned it's not true. My IS38 would blow away my IS20 that I replaced 0-60 and that's supposed to be where the IS20 has an advantage. Sure the peak torque is about 500 RPM higher but where the IS20 peaks my IS38 already has more torque.

Sure the is38 would definitely do better than the is20 in 0-60 but is it that much better to warrant a $1300 turbo and $600 protune? Never mind anything else you want to change to support it.

Now that I’m in that much money I might as well go EQT Vortex for just a bit more.

I still prefer as much down low as possible and any larger turbo typically moves the power up the band. I know I’m very outspoken on this and that fine, to each their own. I’m surely the minority

 

[GTIfan99]

I'm personally looking for a used IS38. Unless I can find one for a decent price that's in good shape, I'll stick with the IS2. Now if I have to replaced the IS20, it'll be IS38 time.

 

[jimlloyd40]

Sure the is38 would definitely do better than the is20 in 0-60 but is it that much better to warrant a $1300 turbo and $600 protune? Never mind anything else you want to change to support it.

Now that I’m in that much money I might as well go EQT Vortex for just a bit more.

I still prefer as much down low as possible and any larger turbo typically moves the power up the band. I know I’m very outspoken on this and that fine, to each their own. I’m surely the minority

Yes the power band moves up about 500 RPM but it still has more torque than the IS20 at any RPM so yes it's that much better. But I posted that for the OP who was asking for suggestions.

 

[sprinks]

Is38s are below 1k on fcpeuro and shopdap right now btw.

 

[MyGolfMk7]

One of the most common reasons people shun the IS38 these days is because there are a lot of good hybrid options that don't cost that much more.

A new IS38 can be had for $1250 from FCP Euro and ShopDAP. In the ~2k range, you have the EQT Vortex, the IHX475, the Littco L450, and (for a little more) the DBV2. All 4 of these turbos require a fuel system upgrade though and it seems like people are moving away from simply upgrading the HPFP and instead doing LPFP and MPI. That adds about $1300. So, you're looking at about 2.5x the cost vs an IS38 which can be run with E30 and "not ridiculous" boost and still make good (and hopefully) reliable power (say 380-400whp). I get it that you have to pay more to get more, but it seems like with these 4 turbos, you have to pay A LOT more and the $ per HP return is significantly worse.

Check my math?

I'm using the Shuenk IS38+ which is a direct swap for an IHI IS38, no additional tuning required. It is supposed to be a bit more robust than the stock turbo. Price is competitive vs a new IHI IS38.

 

[roystr]

@Hoon I actually though you'd be in the anti-IS38 camp since you blew yours! Got any thoughts on max boost to prolong longevity. 29 psi doesn't seem to be it.

@MyGolfMk7 Looks like you've have the Shuenk for about 6 month now? Thoughts? How is it tuned?

Thanks! Great discussion so far.

 

[El_bigote_AJ]

This looks like a really good options for one wanting to keep the lower tq curve of the is20 and keep stock fueling.
Impressive number...

https://www.turbopartscanada.ca/collections/audi/products/mk7-golf-gti-golf-r

 

[MyGolfMk7]

@MyGolfMk7 Looks like you've have the Shuenk for about 6 month now? Thoughts? How is it tuned?

It has performed as advertised, very similar to the IHI IS38. I started using the Eurodyne IS38 tune but based on the Shuenk turbo having more robust internals decided to have a custom tune made to push the turbo a bit more. I'm on 93 only so that will be a limitation.

The data on the TPC20 dynos looks like a typical hybrid with a drop in low end TQ but more top end.

 

[Twist1]

Buy a used is38 for 600$ and you can't really beat that value.

But it needs ethanol to be fun.

And there is pretty much no perceivable difference in lag if that is what youre worried about. The low down tq difference is a non issue.

 

[SugarMouth]

a good IS38 setup is the sweet spot for a GTI. Cost effective, quick and reliable.

Don't remind me.