"Parmas" Motor

[Blown_xa]

Originally Posted by Tamago

positives for top mount
1. less than half the piping
2. cleaner engine bay by simplifying piping and routing
3. puts that gnarly scooped hood to actual use
4. does not block radiator (engine runs cooler)
5. can be thicker than front mount because of Euro NCAP (more room under hood)
6. because of the shorter piping, you see less pressure drop and quicker throttle response
7. because it sits horizontally in the engine bay, it can be sprayed with water easily for quick cooling
8. not damaged by road debris

negatives for top mount
1. if improperly set up, will be less efficient at cooling than a front mount
2. it's not "cool" looking. many ricers equate turbos with front mounts, and if you don't have a front mount, you obviously aren't making any power (this really should be a POSITIVE THING not a negative thing lol)


Positives for front mount:
1. looks cool
2. can be generally longer than a top mount (however, short fat intercoolers are more efficient [less pressure drop] than long thin coolers

Negatives for front mount:

1. silly piping running all over the place (in the case of rear mounted turbos, which is what this is about.. in a longitudinal engine, i.e. supra, front mount is perfect because the exhaust is on the passsenger side and intake is on the driver.. obvious routing is obvious)
2. less efficient because of all the extra bends and charge piping bends. every time you go WOT the turbo has to fill the entire length of charge piping AND intercooler before you actually see boost. this can exascerbate turbo lag
3. attracts unwanted attention (law inforcement comes to mind)
4. susceptible to road debris
5. blocks radiator and AC condenser
6. safety may or may not be compromised (bumper beam hacked) to make the IC/piping fit


that's all i have folks.

good points. A top mount will never provide the efficiency of a front mount though. The main reason WRC Subarus use a top mount is so the intercooler doesnt get ripped off landing crazy jumps. And WRC cars im pretty certain don't run on pump gas, so they don't need the cooling efficiency to supress detonation.

There is a forumula to calculate temperature drop vs. pressure drop. The benefits of temperature drop far outweigh pressure drop. And also the general formula to see the benifits of temperature drop in the charge stream. For every 10 degree drop is a 1% gain in hp. That may not sound like much, but a good example is my car... I ran no intercooler but with WMI. My MAF sensor temp probe was reading up to 280 degrees @17psi (Blow through set-up, before meth).

I just dropped in a Evo intercooler, The charge temps are now the same as ambient, in fact on a few dyno pulls during my last tune the temperature DROPPED a few degrees when boost hit. That's over a 200 degree drop...
At the same boost with the same timing I gained 25whp and 32ft.lbs. of torque. Also my spool up is within 200rpm as before, that isnt even noticable.

I have installed many front mount kits on STI's and Mazda speed 6/3's. Tuning past 250whp (with top mount) on our dyno is like pulling teeth for gains because of the heatsoak. To prevent risk of detonation more timing needs to be pulled. Any good tuner would agree to that. Even the Cobb base maps for the MS3 are specified for either a top or front mount(more conservative timing for top mount).

One thing I constuctively dissagree with is that the engine bay is cleaner with a top mount... I don't think so. Especially with the yaris and Ms3. Just about the only place for the top mount would be on top of the engine cover. I always found it to be a pain to have to remove pipes to service the car. They are routed to where you have to remove them to check spark plugs( which is something to be checked often on a aftermarket boosted car). And on the Subie you have to remove the intercooler to service the transmission /turbo/downpipe. The newer Subies have a smaller sized top mount with composite casing which makes life easier for working on the car, composite casing is for less heatsoak.

I say front mount.

good build, and whp numbers yet?

[advocate]

So if front mount creates huge turbo lag and top mount spools faster but hotter (and thus less boost), how the hell do you pick which one you want? Sounds like very big drawbacks on both parts.

I would think a larger engine, which creates more overall exhaust, wouldn't suffer as much from excess lag from a front mount versus a Yaris which burns much less overall fuel. Correct?

[Parmas]

Job finally finished although it came dark for a good photo... Will get some good photos with all completed...

Next -> lots of tuning and increasing gradually some boost :)

Still not dynod car so I don't want to throw numbers until finished

[Blown_xa]

sweetness

[Blown_xa]

Originally Posted by advocate

So if front mount creates huge turbo lag and top mount spools faster but hotter (and thus less boost), how the hell do you pick which one you want? Sounds like very big drawbacks on both parts.

I would think a larger engine, which creates more overall exhaust, wouldn't suffer as much from excess lag from a front mount versus a Yaris which burns much less overall fuel. Correct?

read my above post. There is no noticable lag.

[rob323]

Originally Posted by advocate

So if front mount creates huge turbo lag and top mount spools faster but hotter (and thus less boost), how the hell do you pick which one you want? Sounds like very big drawbacks on both parts.

I would think a larger engine, which creates more overall exhaust, wouldn't suffer as much from excess lag from a front mount versus a Yaris which burns much less overall fuel. Correct?

You are over simplifying it a fair bit. Both setups can be made to work as good as each other and it depends on what purpose you want to design it for. There's alot of variables to be taken into account though to get it right (eg. piping diameter, bends, pressure drops, turbo sizing and efficiency ranges, gear ratios, cam design/ duration/ timing, engine timing, bov design etc etc).

And if all else fails, turn the antilag on

[cali yaris]

ha, true! just do it my way, that's the best. (just kidding!)

[Parmas]

Some recent pics...

Damn the camera got low battery when I was taking a video. Better luck next time....

[mario98c]

Post Videos!!!!!

[yaris-me]

It looks mean. Does it sound mean?

[cali yaris]

awesome hood, very aggressive.

I would like to see (when you have time) a closer pic of the BOV flange, it looks interesting.

Also interior - any gauge set up?

[blacksandiegovitz]

Originally Posted by cali yaris

awesome hood, very aggressive.

I would like to see (when you have time) a closer pic of the BOV flange, it looks interesting.
Also interior - any gauge set up?

Look like a standard HKS bov flange to me , ie the bov sits in the circle flange and is held in with a C-clip .

Amazing project man I've been following your build and am stoked to see you finally got it all together in the car and running I can't wait to see the dyno #'s

[changchewsoon]

wow parmas, your car looks great!! its a job nicely done! the intercooler is so sexy!

[Parmas]

Thanks guys I appreciate your comments and these are what keep me updating!

The BOV flange is the standard HKS weld on flange as described blacksandiegovitz in his post.

RE: Yaris-me post... well it sounds awesome as described by many here although I need a good camera for you to enjoy the sound

I don't think of dyno it for now but will not miss a video on street.... Please let me enjoy it a while !!!

BTW here is a shot from inside incl. my lovely girl

[Parmas]

Today I went up to a drag race to check how all is working out. Well it was noticed that injectors are maxing out at (about 98% inj duty cycle) 9psi 6000rpm with an average afr of 11:1.

Well although the car runs fine I am sure I will not get a good time with this low boost (thinking of 14s blehh). What do you recommend about the injectors, Brand? ***cc? Type?

I think garm can help me on this :)

Also engine gives startup problems when cold or when not using it for a half an hour or so? Sometimes needs 3 starts to ignite, is this normal or the plugs are too on the cold side?

Thanks!

[cali yaris]

what plugs, and what gap? The gap can make a difference.

11:1 is on the rich side, you'll get a better result around 11:7

sorry, what management again?
Is your car using the ECU's stock cold-start program?

[Blown_xa]

nice. I am curious about final results.

These injectors should work well... http://www.ptuning.com/html/search-r...nd=dw&cmbYear=

they will drop right in and use factory plugs.

Do you have the stock fuel pump?

[Parmas]

Originally Posted by cali yaris

what plugs, and what gap? The gap can make a difference.

11:1 is on the rich side, you'll get a better result around 11:7

sorry, what management again?
Is your car using the ECU's stock cold-start program?

Plugs are Denso Iridium power IK series. Gap is 0.4mm with 5Kohm resistor. Part no is IK22#4

Management is Gotech PROX full standalone, stock ecu not used. Ecu has a map for startup fuelling appropriately adjusted by tuner. I just want to assure that problem is not coming from plugs heat range.

RE: Blown_xa injectors link... why you say "should work fine" are they tested before on a 1NZ?

RE: Air to fuel ... can anyone tell me the appropriate range the afr should be at :

- Idle 1200rpm
- 2Krpm until boost
- above 3500rpm after boost?

Also, since I am considering replacing the injectors to above 600cc, does the engine will startup up rich or lean with a fuel map tune on 340cc inj?

See attachment from a log run at first gear @ 6Krpm ..injector duty are 98%