Well, nearly 2 years ago I decided to sell my turbo Maxima and get an MR2 Spyder. I sold a bunch of parts I had for the Max but never did sell the Maxima. Well, just a couple weeks ago I ended up selling the MR2. I bought my dream car, a Z32 300ZX (n/a, don't want a TT), but I still have the Maxima. After I pretty much decided to keep the Maxima I've been collecting parts and working on it off and on for a while. Here's a small peek and update to what's going on.

On the left if the new turbo, a Holset HX35. Its somewhat comparable to a Garrett GT35 in size but is very different. Its designed for a diesel engine (came from a Dodge Ram w/ Cummins 5.9 diesel). It actually is supposed to have a much wider compressor map than the GT35 allowing it to opperate over a very broad range so to speak.

As you can tell, the compressor is massive next to that Z31 T3 turbo. It should support upwards of 600 hp or so (hey... maybe I can reach my 600 hp power goal that I was spouting off when I was a noob... oh man that was so funny and now embarassing to see. ). Anyways... the reasons I wanted the HX35 are many.

1. They are very affordable. I got this thing for less than $200. It will need a rebuild but is in excellent shape. Even after the rebuild it'll be less than $300 or so.
2. The compressor map is supposed to be very good and, from what I can find, should work out very well.
3. The dual scroll turbine housing is hard to find on newer turbos. Reason I wanted it is I'm planning on making a valve that will spool this thing up much quicker than running it normally. It should spool even quicker than the smaller HY35 that many people use. I'm fairly confident that I can spool it upwards of 1,000 rpm sooner than if it were to be run in a standard configuration.
4. Extra perks like the anti-surge compressor housing, designed to be heavy duty (larger shaft than most turbos use), etc. etc.

I also bought an aftercooler quite a while back when it was still running and with very slight work will be ready to mount. I just recently bought some 370 cc injectors so those will be going in as well. Do some tuning with the romulator and finally, I might have a fast car.

I also bought a brand new Miller welder yesterday so maybe I can finally do some quality welds. Our p.o.s. welder, even though MIG, didn't really get the job done. With only 4 positions for voltage control and many other design issues it made for some tricky welding. I bought the new Millermatic 140 with auto-set so I just select my wire size and metal thickness and weld away. It'll set voltage and wire speed automatically making for a quick and easy process. I can't wait to give it a try and see what I can finally accomplish on my Maxima. More to come very soon!

Anyways... on to the pictures:



More:

http://www.machzracing.com/Maxima/Holset/hx2.jpg
http://www.machzracing.com/Maxima/Holset/hx3.jpg
http://www.machzracing.com/Maxima/Holset/hx4.jpg
http://www.machzracing.com/Maxima/Holset/hx5.jpg
http://www.machzracing.com/Maxima/Holset/hx6.jpg
http://www.machzracing.com/Maxima/Holset/hx7.jpg
http://www.machzracing.com/Maxima/Holset/hx8.jpg
http://www.machzracing.com/Maxima/Holset/hx9.jpg
http://www.machzracing.com/Maxima/Holset/hx10.jpg
http://www.machzracing.com/Maxima/Holset/hx11.jpg
http://www.machzracing.com/Maxima/Holset/hx12.jpg
http://www.machzracing.com/Maxima/Holset/hx13.jpg


Now all I need is a Stillen front lip... anyone selling one?

 

That sounds like a great plan you have there! I can't wait to see what kind of results you get. It's an interesting concept to put a diesel turbo in a gasoline car, do you have any links to other setups that use that configuration? Also, wouldn't it take a larger engine producing more exhaust to get this thing spooling up easy? I'm not sure, but I think that a deisel turbo is set up to run with a very high compression engine, so a lower compression engine (maxima) would make it difficult to spool up the turbo.

Oh, and where can you find a turbo rebuild kit for under $100?

 

Most VG guys using this turbo are spooling in the later 3,000 rpm range if I remember correctly. There are quite a few using an HY35 so I can't remember for sure off hand.

Basically the way they put it is you're putting the turbo on an engine half the size, but spinning two times as fast. The Ram has a 5.9 liter I6 diesel that only spins up to around 3,000 rpm. I'm putting it on a 3 liter V6 that'll spin upwards of 7,000 rpm. Granted compression ratios can make a big difference as well... they still perform very well.

Its also kind of interesting to note that the power ratings of these turbos on diesel engines are pretty much half of what it would do on a gas engine. Say the limit is 300 hp on a diesel, it'll be 600 on a gas engine. Its pretty cool.

You can get rebuild kits for these turbos on ebay all of the time in the $70-$80 dollar range. One place on there will even rebuild it for you if you send it to them. I'd have to do some checking around to see how good they are before doing that though.

 

What's the compression ratio on a diesel? (look it up, then do all that math again).
that 6L diesel at 3000rpm will be sucking twice as much air than your car will at 7000rpm.
I also highly suggest you get a compressor map for that thing and actually do the math instead of take other people's word that it works. been there, done that, have three "these *should* work perfectly for your car" turbos on the bench collecting dust.

 

They work, and they work very well. Many people already use them so I have no doubts.

The compressor maps are very hard to get. Holset keeps them very secretive so chances of getting one from them is nearly impossible. The ones I have seen floating around show that its a very good compressor. Either way though, like mentioned above, they're already being used on many cars (quite a few Z31's even) and they work very well.

 

Haven't got much done turbo wise but I did get a different intake manifold setup. It will match my piping a little better and will probably flow better than the stock manifold.

2nd gen Maxima upper manifold, Pathfinder lower manifold, 240SX throttle body, 3rd gen Maxima throttle body linkage stuff. I put some 370 cc injectors in the Maxima fuel rail but the rail is just barely off on the Pathfinder lower so I need a Pathy fuel rail. Anyways... so far it all fits up pretty well and it should perform pretty good. It will probably have a little more top end than the stock intake but it'll still be fun.

I do still need to port match the upper intake to the throttle body but other than that its pretty much ready.

Here are the pictures:



http://www.machzracing.com/Maxima/Intake/intake2.jpg
http://www.machzracing.com/Maxima/Intake/tb1.jpg
http://www.machzracing.com/Maxima/Intake/tb2.jpg
http://www.machzracing.com/Maxima/Intake/tb3.jpg
http://www.machzracing.com/Maxima/Intake/tb4.jpg

 

I wanna hear about the 300zx, as its on my list of next cars. What year did you pick up and why not a TT?

 

isnt' the tb sticking out there going to take up some much needed space for that bigger turbo?? interesting none the less, injectors will be easier to get to.

 

Miller > *

 

I got a 91. I didn't want the TT since I'm swapping in the VH45. The N/A is slightly lighter but more importantly, it has an R200 differential. I want to use the Q45 differential as its a 3.54 so it should fit the engine real well once I get some boost. Nice broad gearing to match the broad power band. What's really cool about the Q45 R200 is it actually uses the TT style output flanges and axles... monster axles. I don't think I'll be breaking it but if I do... I'll just skip right to the Armada differential. Its like the TT diff, but even bigger and with a lower ratio than even the Q. 230+ mph gear limited top speed anyone?

I'm actually moving the turbo forward a little bit. It'll basically be sitting parallel with the radiator, compressor side pointing to the driver's side and the turbine exiting towards the engine with the exhaust going under like the normal exhaust setup. Before I start placing the turbo, I need to make my "quick spool valve"®©™∞ . Once I get that done I can start mocking up the pipes and such.

Injectors are definitely easier to get to. I put them in and put the manifold on and I could easily access them.

I forgot to note that this manifold has been flow tested and it outflows the Pathfinder manifold at lower lift (.1" - .3") and if it were modified like so: http://www.mgpautoparts.com/guttedPl...ttedPlenum.htm it would definitely outflow most of the intake available for the VG out there.

 

a 6L at 3000 rpms is technically like a 3L at 6000 rpms.. compression ratio has no effect on how much air its moving just how small it compresses the air. That thing will spool good. Compressors have a very little effect on spool time. Its all the exhaust side. That exhaust side is a lot smaller than the one ive got, and i spool by 3000-3500. Ive seen that turbo work well on 2 liter and smaller hondas. Its a rather nicely sized turbo for a VG. Make everything exhaust wise as high flow as you possibly can, thats my only advice. A turbo is only as good as the setup its bolted to.

Also.. I believe that Quest/villigar Fuel rails will bolt onto that lower plenum... They use the newer style Nissan injector.. which you can buy from deatchwerks for a rather good price.

 

Show me that in engineering terms.
there are SOOO many things that change when you start altering compression ratios, displacement, and engine RPM. a 6L diesel at 3000 rpm often runs much more efficiently than a 3L gasoline engine at 6000rpm. also think about the velocity of the air going through the tubing. Those things make much more difference than you'd believe, and that's why you pay the good shops big bucks to PROPERLY build and tune a system. anyone can bolt on a 'it should work' turbo and make boost, but to make good power with maximum reliability and minimum hassles, then you need to make sure you've got a properly sized turbo.
and yes, the compressor makes a big difference in how the thing spools. the exhaust flow makes it spin, but if you have a huge, heavy compressor wheel, then it'll take longer for it to spool up. for a smaller, more responsive engine, you'll want a smaller, more responsive turbo. If you're going to stick the car wide open and hold it at a certain RPM (like a diesel or airplane at cruising speed), then a huge turbo is just fine because you're not having to spool it up constantly- it just stays moving. that's just simple physics- not rocket science.

 

Really, this turbo is a lot like the GT35 but with an even better compressor map. They say the a/r is comparable to a .80 or so. The big difference is the Holset turbines are flat and wide compared to Garrett's being tall and narrow so the conversion won't be exact but anyways... The thing to keep in mind is that on a diesel, having a narrow power band, they need to spool pretty quick so the turbine will likely be on the small side for the actual size of the engine and such.

Either way, due to Holset's advanced wheel design, they spool very quickly. On top of that, I'm making a valve that will make it spool even faster. I found a compressor map for the HX35 on Garrett's website of all places. It fits up very, very well.

 

about the 6L to 3L, yes there is a lot that alters it and changes it, and yes .. a diesel is more efficient.. but that is because for one, diesel fuel has more energy in it, and its higher compression. That doesn't mean it moves twice the air per displacement. Besides Compared to the turbos that alot of other manufactures use on there diesels, that cummins turbo is REALLY small. a 7.3 liter for turbo is Huge compared to it. Im not really sure why Cummins used such a small turbo. Boost instantly i guess but that sacrifices top end.

Im just curious matt.. how many cars have you boosted...? ive turboed my fare share (counted at least 10 in my head). and what i speak from is experience. About the spool up and compressors, if thats entirely true, then how is it that when i installed a MUCH larger compressor on my turbo (from a to4b 60 trim to a 62-1) it actually hits boost faster. yes wheel weight will effect how fast the shaft speed increases, but.. a larger compressor doesnt have to spin as fast in order to move the same air, there for canceling it out if not even inproving on spool time.. and besides , what would a compressor map tell you about spool time anyways..

Yes in order to fit a turbo to an engine to have the "BEST" over all power band requires alot of research,(there really isn't a "best" its all based on preference. mid-high power, low-mid power..) But when you actually try some stuff, you will have much better luck than you think. Most of my turbo selections, are based on how ive seen it perform on similar sized engines with similar flowing heads and setups and how that person wants it to perform. Ive said it many times.. The numbers say my turbo wont work, but one ride in it and i will prove you otherwise. Unless your building a complete race car.. don't over think it. Dont just slap any turbo on, but for a setup like marks doing.. he doesnt need to search and search for the "best" possible turbo. I Personally think that its a bit on the small side.. but thats just me, i just like the top end power of the larger turbos. Most people would love the power band of that turbo.. Good luck mark.

 

the big one compared to the small one hmmm

 

Thanks. I think this turbo will be a mid to high range turbo. I know of a Z31 guy off the top of my head that spools his HX35 to 18 psi by 3,600 - 3,800 rpm. I'm fairly confident with the valve I'm making that I can get to that point by, at the very least, 3,000 rpm basing off of his setup. With some other ideas I have I believe I can get this thing to be fully spooled by 3,000 rpm or much less yet still retain all of the top end. It will definitely be a blast with this turbo.

The perfect turbo should hopefully be coming out soon, though it will likely be too expensive initially. Honeywell/Garrett is working on a variable compressor finally. We already had variable turbines, which really helps out spool times however the compressors were still an issue since you could still essentially spool too quick and cause surge or have a low surge line and not have enough top end. Having a variable turbine and compressor would literally make for the perfect turbo. I can't wait to see what those things will accomplish.

 

Alright, I have the valve about 3/4 of the way done and I'll have some pictures of it up very soon. I'm just waiting on 3 T3 flanges I ordered and I'll start welding it up the rest of the way. Its looking surprisingly decent at the moment for using mostly hand tools. The only decent fabricating tool I have is really the new welder... and maybe a cheap drill press from Lowe's. I still need a lot of stuff. I'm looking into getting a band saw very soon as that would help out so much. The cut off saws just don't do precise enough cuts for this kind of work so I've been doing it by hand to be sure it doesn't go crazy. From there I just hand file it down to get it exactly where I want it.

While in the process of working on that though I've considered pulling the engine and throwing the heads off of it onto my stock block I have laying around. I took apart my other engine for some reason so will use the parts from this one to put it all back together. Reason to do this is to get the 9:1 compression back plus the euro cams are supposed to be in the JDM engine so I'll hang onto those. Woohoo for ~10 extra horsepower...

Anyways, there are quite a few other good reasons for doing it but the compression ratio change is the biggest. That'll help out the low end power a good amount plus could potentially get be a tiny bit more gas mileage, not that I was doing all that bad on the highway... with a absolutely ****ty *** redneck setup and a bad tune I still managed an avg. of 29.5 mpg at one point. I know I can get it well into the 30's with a much more efficient intake and exhaust setup and a solid tune.

Alright... so this is what is going on:
Finish "quick spool valve"
Make new exhaust piping fore and aft of turbine
Finish hybrid intake manifold setup (which only consists of getting a Pathy fuel rail)
Finish up aftercooler setup and route piping
Run new battery cable to trunk as 4 gauge will not cut it
Install and program Romulator (most of the hard stuff already done really, mostly just plugging in and tuning)
And lastly I really should get a Stillen lip to fit the aftercooler so I'm looking for one of those

Possible changes:
Put old engine back together with new heads for some more power and potential efficiency
An even crazier intake and possibly exhaust setup for even more efficiency... it may be a while down the road though as I just want this thing running

 

Here are some pictures of the valve. I have it a little more complete right now with some modifications done to one of the T3 flanges. I'm getting read to go take some more pictures after dinner and I'll get those posted. I should also be finishing the valve tonight so I'll get those pictures on here as well. (yeah, that work table is an absolute mess... I don't recommend working on multiple car projects at once... )

http://www.machzracing.com/Maxima/QSV/P1020113.JPG

http://www.machzracing.com/Maxima/QSV/P1020114.JPG

http://www.machzracing.com/Maxima/QSV/P1020115.JPG

http://www.machzracing.com/Maxima/QSV/P1020116.JPG

 

i would really like to see how this works out.... i am very interested...... i'm learning more and more as you guys go on..... i want another maxima, and i have plans, but no money....

 

Looks like headgasket destruction waiting to happen

 

Alright, got some more pictures. I almost have it finished but messed up a few things (fixable) so I'm probably going to finish it tomorrow.

Welds are decent, could be better. I didn't want to get too close to the side so that it didn't weld the pieces together.
http://www.machzracing.com/Maxima/QSV/P1020155.JPG

Took the welds down a bit to hopefully assist in making it flow a bit smoother
http://www.machzracing.com/Maxima/QSV/P1020156.JPG
http://www.machzracing.com/Maxima/QSV/P1020157.JPG

Got the other side tacked on
http://www.machzracing.com/Maxima/QSV/P1020158.JPG
http://www.machzracing.com/Maxima/QSV/P1020159.JPG
http://www.machzracing.com/Maxima/QSV/P1020160.JPG

Here I basically matched one side of the flange to the valve assembly to try keeping flow decent and turbulence down. Its not the straightest match but should work pretty good.
http://www.machzracing.com/Maxima/QSV/P1020161.JPG
http://www.machzracing.com/Maxima/QSV/P1020165.JPG
http://www.machzracing.com/Maxima/QSV/P1020166.JPG

I hit two corners but it shouldn't be too bad. Since I'm not really sure if this will work or not I'm not working too hard to make it absolutely perfect.
http://www.machzracing.com/Maxima/QSV/P1020171.JPG
http://www.machzracing.com/Maxima/QSV/P1020172.JPG


http://www.machzracing.com/Maxima/QSV/P1020174.JPG

Here's what it'll basically look like:
http://www.machzracing.com/Maxima/QSV/P1020175.JPG
http://www.machzracing.com/Maxima/QSV/P1020176.JPG
http://www.machzracing.com/Maxima/QSV/P1020178.JPG

The valve open for top end
http://www.machzracing.com/Maxima/QSV/P1020182.JPG

Closed for faster spooling
http://www.machzracing.com/Maxima/QSV/P1020181.JPG

 

lol, good times, good times where had here

 

Naaaa... he will be just fine...

 

As long as I keep the fuel delivery there, I think the head gasket will last a very long time. I think they've been proven to handle upwards of 30 psi on a VG pretty well. Those 13 head bolts per side really make a difference.

 

How many does my VQ30DE (soon TT) have?

~Alex

 

I believe most of the DOHC V6's have 8 per head.

 

WTF are you 2 yammering about??

 

Head bolts... the VG30E(T) has super duper head clamping capabilities.

 

I know only jokin'

 

Oh well my engine has 10:1 cr and still loves boost

Get any more done on the project? I cant wait to see it finished...

~Alex

 

I finished the valve tonight then stared at my car for about an hour or more trying to figure out the best way to mount the turbo and such. I still can't decide on a good spot for the turbo so I may even change the design of the valve to give me some more room but I can't decide. I'll be sure to get some pictures of the finished valve up asap.