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IS38 APR tune?

Ironshade

Go Kart Newbie
Location
Atlanta Ga
Is38 with a 5MT would be a killer roll race combo. Reasons here
5MT long gearing 2nd 72mph 3rd 113mph 4th 148mph

Now.. even tho is38 more lag. It also has capibility to hold boost and still blow cold on our motors at 7K rpms. 7k shifts on the is38 would make it one hell of a roll car. There wouldn't be a problem from 2-3rd shift turbo lag problem at all. Car will rape most things tbh. spool would probably be ~3500 but when you hold power past 7K thats one serious powerband.
 

toledospeed

Go Kart Champion
Location
3rd rock
I can see why some would want to chase more power, but personally I would not want more lag. The IS20 is a perfect fit for me, I really an enjoying it thus far. The lag difference between the IS20 isn't very recognizable and I don't spend much time above 5500 RPM. I would like to understand what characteristics a hybrid IS20 would bring to the table. Was reading about GLI with a beast of a hybrid and the IS20 would be even more impressive. Too bad we are still in the early stages of those developments, especially in the US, or it would have been very tempting if this was offered in my area.
 

TwinDad

Autocross Newbie
Location
Fort Lee, NJ
I think with more and more IS20 1.8s showing 26psi peak and holding on to over 20 at redline, it isn't helping the IS38 case for this engine. I really think the top end power you pick up will come at a greater sacrifice to the low and midrange. Purpose built roll racer could be nice. The longer gearing of the 5spd isn't anything great though. It just means that it will take that much longer to wind out each gear. The auto would probably be a better bet. I think the ideal car for it would be a 4motion S wagon with either the 6spd manual or the dsg.
 

MeltedSolid

Autocross Newbie
Location
San Francisco Bay Area
Car(s)
'15 Golf, e36 328i
I agree with Ironshade. Under ideal conditions one could never drop below 4000rpm with our 5mt, and even if the IS38 would only spool at 3700rpm that's a non-problem for roll racing. Additionally with that much power the amount of time it takes to shift begins to outweigh the benefit from shorter ratios so I could see an IS38 TSI taking down stage 2 GTI's with ease in that situation. The problem with it is it wouldn't work for anything but roll or drag racing because anything short of always being in the lowest gear possible would be nothing but turbo lag. If you found yourself at 30mph in 2nd gear or even 55mph in 3rd gear it would be crippling. I even experience this a bit with the IS20 while autocrossing, where if I floor it at 25mph in 2nd gear I pretty much have to wait around until it gets over 30 then it builds boost and takes off. I personally don't think I would ever pair an IS38 or bigger turbo with a 5MT unless I was building a dedicated race car.
 
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