mystique

I am reading all this info on sites about Japanese cars that have been turbo'd, and it makes me wonder. I am no expert on the subject, but how can something like a Honda or Toyota push 500-700HP when they have turbos, and the Audi's are in 300-400 range, for A4's and S4's? I love my A4, but I guess my question is this - are there limitations on the Audi engines that limit their max HP compared to some of the Japanes cars. Why is this the case between the Audi's and Japanese cars? What are the differences in engineering, whatever, that allow for this craziness? I am looking at a Supra in particular(not to buy), but also looking at Honda. Some of these cars are like rockets...Any explanation on this would be enlightening and much appreciated...thanks...

Bollinger

You need to spend a lot of dough to make 500-700HP. Here's why so many Japanese turbo cars make 500-700HP. Because many ricers lie.

An Audi S4 can be made to make 500HP approximately as easily as a Supra. Both are very difficult.

A little over 500HP should be no problem on an S4 with a Stage III and nitrous. Of course you need a new fuel regulator, all kinds of new piping and some way to trick the ECU into dumping more fuel in when you turn the nitrous on.

Bottom line, don't believe everything you read. High HP figures like those do exist, but require significant aftermarket modification. And this has plenty of reliability downside.

Mike@Ikon Motorsport

The two Japanese engines that run 600HP and can be driven on the street are from the Toyota Supra and the Nissan Skyline. They both have very strong bottom ends, and can hold a LOT of boost without any internal work. Another factor is displacement. Lets say you manage to squeeze out 200HP per liter. That equated to 600HP in a Supra and 360 from the 1.8T in an A4. Now, compare the S4 2.7 to a skyline. First and foremost the Skyline 6 has been around for a long time and was designed as a turbo engine. Basically the 2.7 was a de-bored 2.8 with lower compression and tacked on turbos, thus only 250HP stock.

Also take into consideration the acura integra vs. the A4. Install a turbo in a VTEC integra and you get anywhere from 220 to 260HP at the wheels with just a bolt on kit. Impressove but nothing absolutely stunning. Install a larger turbo on the audi 1.8 and you can see over 300HP on stock internals. What gets tricky is that, the integra is ALOT cheaper. Therefore you can rebuild the engine and etc for a lot less money than you can the 1.8T. If you pay close attention to the the Integra 1.8 and A4 1.8T is that the both create nearly the same HP with stock internals. It is just that there are cheaper parts for an integra. Plus the GS-R only weighs 2600lbs and doesn't have quattro sucking power away from the ground. Long rant, but anyone with more info care to expound on that.

Mike

Mike@Ikon Motorsport

The 2.7T can be made to have 500 HP, it has been done. There is an owner in the S4 claiming that. But, that requires serious money, upgraded turbos and etc. In the end though the supra and skyline will have more potential than the 2.7.

Mike

mystique

Thanks for the info....Unfortunately, my knowledge of engines is not that great yet. I realize some of the people(probably a lot) inflate HP numbers, but I know these cars are out there. Anyways, I was just curious about the subject. Thanks again...

sony

There are many modified Japanese cars in Japan that has more than 600hp. Supra and GTR are not the only. You can push as much as you want. It is up to your $$$$. For example, I saw Aristo (Lexus GS)650hp, NSX, Lancer EVO and Toured V with 700hpetc....you name it. Well, let's say Supra and GTR are the stereotype of heavily modify Japanese cars.

Bollinger

A Nismo will make 600+. Nismo's are few and far between. Not that there aren't non-Nismos making 600. But the numbers of cars making that much are still quite small.

There is an excellent turbocharged Aristo (like a Lexus GS) available in Japan. I believe there is also a turbocharged Altezza (like a Lexus IS) too.

Honda even makes a turbocharged car (micro van) in Japan. Only one though I think. But I can't imagine they can compete with the WRX in the future without a turbo.

Dr. Mike

Hiya,

From Integra experience, the 1.8L VTEC block (aluminum), rods, pistons and crank will reliably handle ~240hp. Any more and you must replace the rods, pistons and crank in that order. These engines are optimized for high rpm, lightweight components and excellent oil and coolant flow (VTEC & Type-R 1.8s have oil jets directed at the rods, for instance). This job on this motor will cost upwards of $2-3k depending on what kind of deal you get on labor. Secondly, this motor features a short stroke (again for high rpm, high hp) and will match up well to a high flowing turbo at high rpm (read here-unbelievable lag). Last off, I use to race (Auto-X and drag) a GS-R with only ~200 flywheel hp and it was real pain keeping torque steer in check and good traction (Type-R has that nice Torsen). Wheel hop on the strip was also difficult to manage.

Now the Audi 1.8T is a different animal altogether. It has origins as a diesel motor (overdesigned block and crank compared to gasoline motors) and a nice long stroke. Perfect for high torque, low to moderate rpm useage. The 5-valve cylinder head on the face of it looks like a good high rpm setup (and it is, but it has been abandoned in F1 in the name of simplicity vs. actual benefit) but Audi uses it to increase fuel/air mix in the long stroke motors, again, high-torque. That $2-3k you used on the Honda motor to get it ready for a $3-4k turbo job is unecessary as the block, rods, pistons and crank will all take up to 400hp. You just need the $3-4k turbo job.

Over 400hp from 1.8L? (not talking GT-R or Supras here) These cars are COMPLETELY different than the normal street cars in both the German and Japanese examples. You will see them at the dragstrip and in magazines only.

Michael

Bollinger

great post, great info

jasyn³

hearing a turbo spool on that little van slapped a big smile on my face. .heh