KLT-MX3

Unless you're going for over 500 whp thats some wrong turbo sizing there buddy.

I made 400 whp on a holset HY35, and will be shooting for higher 400's.

How much power are you going for? If you plan to stay around 10-15 psi (on that little motor, I might expect 250 whp tops?) its just not right. You can get more streetability out of a smaller unit.

mkehler

Just curious, how come you went with maching the Garret housing vs getting a Bullseye housing? For the $140 or whatever they are, I can't see it being worth the headache and cost of getting another one machined. Unless maybe you had it lying around and got a buddy to machine it..

anyways, nice job.
Matt

unclepowers

economics....u just answered ur own question..

Tom-Guy

VIDEO PLS

NBLKID

sixsick6

Seconded, even thirded. That turbo is a waste of a turbo on your engine and the only thing allowing you to spool it is the .48 exhaust housing. Even if you're somewhat spooling it and getting a large amount of flow, it's still on the bottom end of the compressor map and you aren't getting anywhere near the potential you would if it were installed on a larger displacement motor. Why some of you install the largest turbo you can find on the smallest motor available is beyond me? (granted you probably bought the turbo cheap and the car is a throw away/fun project....but you would be much happier if you would have taken the time to suit turbo to displacement and actually taken the time to do the math and adjust accordingly for your application)

The compressor inducer in Holsets vary from 51 to 55mm to 66 on the 40 series. The compressor exducers are 77mm to over 80mm. Turbine wheels are 65mm (same size as the garrett t3 stage 3 wheel) The turbine housings generally have an a/r of somewhere between .63 (t3) to a .82 A/R. The HX40 compressor wheel is good for 75 lbs/min.

A good comparison for a map would be the T64:

Which chokes at 70 lbs/min

Dodge turbo diesels with these turbos are making 400-500 ft lbs on stock boost levels from 1700 to 2700 RPMs, but their enginess are ALOT larger than yours. They're passing right through the "island" while you're asking "How do I stop compressor surge?"

Simple answer, you're not going to. Too much turbo, not enough engine. With your stock bottom end and your no doubt "newb to boost" status, I'd give your stock bottom end 1 month if that if you can spool this turbo to any decent pressure ratio beyond 10 psi. When you're thinking in terms of boost, don't get lost in the Import Tuner "tech section" where they seem to believe 10 psi is the same with all turbos, it is not. You need to start thinking in terms of pressure ratio and calculating turbo to application based on your theoretical volumetric efficiency WITH said turbo and also factoring in density ratio as well. It doesn't matter if you can spool it if you're wasting the potential that you could have had you installed a better suited turbo for the application. Granted this is HMT and most of you are going to think along those terms and say something like "---- your calculations" but you have to use them whether you like it or not. They're correct just as I am correct in posting them. You can slap on turbos all you want but it doesn't mean that you're doing it correctly just because you managed to get 10 psi on a turbo thats good for 30~40 psi and have had surge the whole way asking yourself "why?"

I just said why and it's as simple as that.

Brandon's gonna love this:

QUOTE=SixSick6 "There are always tradeoffs when mating a turbo to a particular engine and this is why it is so critical to do it right the first time. Add the wrong turbo and you can make your car sluggish, peaky/spiking, or completely unstable under any boost level. Sure you can use any turbo for any application, but that doesn't mean it is CORRECT for the given application. This is why turbos are so magical and if you do it correctly, yes, you CAN find one that works BEST.

Engines themselves have varying amounts of flow required at various rpms and usually a turbo can benefit the engine more in a narrow operating range rather than a broad range due to the fact that the engine varies tremendously and is very complex throughout the entire rpm range. This is why dyno tuning is CRITICAL in "modding".

There are a couple ways to do things, the right way, the wrong way, and a way that works but doesn't work as good as it could/should. I group you in this catagory as you seem to have installed a turbo that is beyond your needs. Improper engine calibration is a great way to end up with a turbo that is way to large/ill suited for the intended application. Usually when you put the same amount of effort into actually planning rather than just bolting on, you can have 1) more power 2) better response 3) better driveability overall.

The trick is to use math and science along with some ordinary "ghetto tuning/streetknowledge as well. Sure numbers may just be numbers and if you use numbers only, you don't have any real word experience. Kinda like a guy who has a bunch of ASE certs but can't tell the difference between transmission fluid and a quart of oil because it isn't something that he see's in a book.

Seriously, forget about peak power at the highest revs and calculate air flow and pressure ratio numbers at the lower portion of the rpm range that are critical for good acceleration....this IS what you're trying do...go fast right? So, why not keep the turbo working within the most useful portion of the engines rpm range?/What good is a motor that gets peak power at 5,900 rpm on a 6K redline if you can only do it a handful of times before it breaks?....again...this is a good enough is good enough thing.

If you're trying to maximize power you need to think that a forced induction motor will almost always shift peak engine volumetric efficiency to a higher rpm anyways, which in turn will raise peak HP more than you could predict going by boost alone. As far as WHICH turbo? You need a turbine that will spin the compressor fast enough to make your target boost but still manage to minimze backpressure. As you know a larger turbine tends to make less backpressure than a smaller turbine, but, a larger turbine is also a larger turbine and you need to prioritze low end, medium or high tq from the get go but also realize that available tq at the wheels is isn't solely turbo but begins with the N/A engines tq itself enhanced by the tq multiplicationfrom the final drive ratio in that particular gear."

That being said, here are KLT-MX3's (Brandon's) rods after his insane 400 hp jaunts through the "Mile High City" in his teal egg:


Which are no doubt MUCH MUCH MUCH MUCH MUCH more stout than your rinkydink Honda Rods. Don't be offended either, I'm only telling you the truth as Brandon already has as well. Too much turbo, not enough engine/not enough stoutdog.

Here is a Holset HY35/HX35W as they are almost an identical map:


If you'd like, I can show you how and why you're getting nothing but surge on your HX40 which is quite different than the HX35...but I can still show you why on a smaller turbo.

Or on a more comparible map to what you actually have, the HX30:


Give me your exact displacement/redline/bore and stroke and I'll plot it on the HX35 map to show you exactly how bad of a decision the HX40 was for your motor. As said, the only thing thats helping you is the .48 exhaust side.

There is a reason the diesels they're installed on can spool them without a problem 1) displacement 2) they have 18, 19, 20, 21:1 compression ratios and spool them at 20~22 psi from the factory. Your 10 psi isn't doing jack bone beside giving you a boner because you managed to squeeze 200hp on a basketball sized turbo that you could have easily done with a T3 60 trim and a .63 A/R exhaust housing and still had time to turn up the boost and gotten a much stouter boner with, also with far less risk and much more streetability.

crx2fast

hummm.. very interesting, glade it worked out for ya. i vid would be nice

hotrex

agree with we need video verification.

Tom-Guy

And once again, sixsix6 doesn't quite get it.

Hello? This is HMT? Most of these guys install turbos that are way to small to make power.

Uh, newsflash? He said he corrected the surge.


You haven't seen the video of the 1.8 liter 4 cyl spooling the stock - no turbine housing swaps here - HX40, have you? The swedes are all up in the HX30-55 series on four cylinders.

A few points:

- given that .48 AR housing, makes sense the turbo should spool better than on the low CR 1.8.
- you are calculating compressor maps divorced from turbine maps, and shaft speed. A compressor map is not carved in stone and is at best a ballpark estimator. You need actual turbo housing/compressor/turbine/engine bolted to dynamics.
- why do you need bore/stroke for old boy's engine? Useless information. You would be better of asking for a dyno chart of a stock engine.

sixsix6, let's not discuss this guy Brandon's car. Let's discuss your car, and what you have done that makes you an expert on OMG WHY THIS TURBO ON THIS CAR IS RUINING YOUR LIFE. Sure, I can see it being too big to spool quickly, and makes for a horrible street combo. It's going to end up running about as well as a no-power-making IHI - so flame the 75% of HMT users that run D15/IHI combos while you're at it.

I have hands on experience with any number of cars, I have Holset experience, and given a wide variety of other experiences I'm not doubting the HX40 is spooling without surge on a D15. Sure, it isn't an ideal turbo for the car. So what?

Jcushing

i give this dude huge props cause he made a post asking how this setup would work, got no REAL for sure answers so he ------- went and did it. now hes out there actually running this combo on his car. so now i the innocent bystander will trust either the guy actually running it SAYING that it works or some homo bench racer e-hating on the guy that is actually running it.

heaven forbid anyone actually trys something in the real world to see what happens instead of just looking at some numbers and pictures and saying no.