M35 Vq25det Runner Spacer

[pixel8r]

The turbo will not spool later, as more air is getting sucked in, meaning more air is sent through the exhaust manifold which means it would be travelling at a slightly increased velocity and past the exhaust wheel of the turbo, please explain to me how this will cause extra lag? Also please note that in my original post I specifically noted that the turbo spooled 200rpm earlier. This is from experience and not theory.

Just thinking aloud - the speed of the air would be higher through a more narrow opening than through a larger one. If the overall pressure is reduced, then even though there is more air, it may well be flowing slower.

Of course, if the pressure is the same as before, then the air will be faster (ie. more air, same pressure = higher velocity)...but the point being made is that the turbo will spool later - which _could_ happen if there is less overall pressure due to the increased volume in the plenum. Does that make sense?

However.....IF this extra volume in the plenum helps the engine to breathe better etc, you may well find it revs FASTER, therefore getting onto boost SOONER albeit just higher in the revs...

Just throwing some ideas around - I'm sure you've already done the same while you were thinking about it

[andy65b]

Fitted my "IAMHE77" M35 spacer special today.

The process is very simple and and requires a bit of dissembling of the motor but should be about a 3 hour job for those not sure what they are doing and if you are really good with a spanner, about 2 1/2 hours.

Net result is that the car definitely feels like it has more torque and on my car with the stock turbo felt a little stronger towards 6000 rpm.

I am not sure about fuel economy improvements.

It is hold each gear much longer without kicking down which is a big improvement.

Thanks Cam

Andy

[iamhe77]

No worries Andy, glad you like it.

Nice to be able to keep up with accelerating traffic without boosting, eh?

[scotty nm35]

Nice results Cam, I may be interested...

May I ask what price they are selling for?

Have you looked into making them from insulating material yet?

[iamhe77]

Nice results Cam, I may be interested...

May I ask what price they are selling for?

Have you looked into making them from insulating material yet?

Oh, I see... so Andy's word has more cred than mine, eh Buddy?

Full kit (including OEM gasket, spacer, bolts, bracket extensions) is $300.

No, I have not looked into it yet.

Edited January 18, 2010 by iamhe77

[iamhe77]

Okay, so after a fair while of running the aluminium spacers (and enjoying the benefits!) there will be kits with the spacers made from Phenolic which will eliminate the heat soak that the aluminium unit suffered from.

This will lower intake temps, which should provide a power and torque increase instead of just the torque increase of the original.

As for pricing/timing/pics etc.... I am sure Andy will fill you in as he is the catalyst behind the change

Edited March 5, 2010 by iamhe77

[zei20l]

very nice work guys!

whats phenolic again?? some sort of plastic??

[andy65b]

very nice work guys!

whats phenolic again?? some sort of plastic??

it refers to material that is a composite of resin and almost any other material and is set with heat and pressure.

Makes it very durable and extremely heat resistant.

we should be able to post up pricing next week.

Cheers

Andy

[Stinky Rooster]

Just thinking aloud - the speed of the air would be higher through a more narrow opening than through a larger one. If the overall pressure is reduced, then even though there is more air, it may well be flowing slower.

Of course, if the pressure is the same as before, then the air will be faster (ie. more air, same pressure = higher velocity)...but the point being made is that the turbo will spool later - which _could_ happen if there is less overall pressure due to the increased volume in the plenum. Does that make sense?

However.....IF this extra volume in the plenum helps the engine to breathe better etc, you may well find it revs FASTER, therefore getting onto boost SOONER albeit just higher in the revs...

Just throwing some ideas around - I'm sure you've already done the same while you were thinking about it

Close, but no cigar.

You have to think in terms of an NA vehicle, when you are this close to the cylinder. Air speed is king at this point, so a longer inlet tract allows the inllet charge to speed up at lower revs, allowing better cylinder filling, which allows much cleaner combustion, and ergo, more torque generated at low revs.

The offset of this, is as revs increase (and by default, airspeed) the advantage of a longer inlet tract becomes less of an advantage due to the pressure differential caused by the bottlenecks in the short turn radius, valve stem guides and even the valve throat itself. There is a certain RPM threshold for any motor when then length of the inlet tract and the extra air speed it generates become a liability. This is why manufacturers have played with variable length inlet tracts for years now (first one I know of is the EL-EF "snail shell" inlet manifold) -*warning - physics alert* because according to Charles Law, with excessive air speed, the added pressure generated at this point will lead to an increase in the temperature of the inlet charge.

Its for this reason that a phenolic spacer would make the most sense, by not retaining any of this extra heat being generated, although carby spacers were traditionally made from this material more for their ability to isolate the carb from vibration (which allows for much better fuel atomisation), as well as increasing inlet tract length,

As for the increased volume of the plenum, this would be a neglible percentage, and if it did affect the level of RPM that boost was acheived, it would be so tiny as to be uncalculable (we are talking microseconds here) Keep in mind that the boost limit is set by the efficiency of the turbo and its ability to provide a given level of boost at a given RPM. Its only when you put something with the volume of, say, a FMIC within the inlet tract would you notice any difference.

[iamhe77]

Cheers for that Dale

Well, I have been running around today with one if the phenolic spacers on my car and I can tell you that they are better than the aluminium one.

Car seems more "solid" and "together" than with the aluminium spacer, particularly in the lower rev range and after a rather spirited drive to work (winding hills, round abouts, 100kph zones) I could rest my hand comfortably on the plenum... which, if any of you have tried on a stock car is virtually impossible without getting burned.

Definitely recommended.... for any type of driving.

Edited March 9, 2010 by iamhe77

[scotty nm35]

Got mine fitted too, thanks Cam. Pity I can't start my car. Starter has died.

[QWK32]

are you guys worried about the phenolic material cracking or breaking under the pressure of being compressed by the plenum studs/bolt? i work on some equipment the uses phenolic material, and as hard and heat resistant as it is, i have found that after some time in use it can become quite brittle and pieces chip away or even crack through.

[Jetwreck]

are you guys worried about the phenolic material cracking or breaking under the pressure of being compressed by the plenum studs/bolt? i work on some equipment the uses phenolic material, and as hard and heat resistant as it is, i have found that after some time in use it can become quite brittle and pieces chip away or even crack through.

No not worried about it cracking or breaking under pressure. What type of application are you using it with? What type of Phenolic are you using....canvas? Heat rating?

Not being a smart arse either...just interested.....we've done a fair bit of research into the type we have used but we also welcome any further info that people might have.

Edited March 9, 2010 by Jetwreck

[mxfly]

Im keen as French mustard for the spacers, just let me know the pricing on them pls

Oh and Andy, thanks for the chat today mate

[QWK32]

No not worried about it cracking or breaking under pressure. What type of application are you using it with? What type of Phenolic are you using....canvas? Heat rating?

Not being a smart arse either...just interested.....we've done a fair bit of research into the type we have used.

I dont know the exact composition but it is some kind of material/canvas and resin mix. heat rating up in the 250-300 deg C range. Used for components in large industrial ovens. Granted they are constantly used in temps above 200c the better part of each day, which would be more extreme than an engine bay. But have found that if i'm not careful during installation it will damage easily. The most frequent failure i see is with phenolic wheels, sometimes only lasting a couple months before they fall to bits.

I may be familiar with a different grade of phenolic than what your using though, i don't know. I knew you guys would have looked into it, i was just interested in your thoughts/findings, as the phenolic i'm familiar with i would not be comfortable using anywhere on my engine.

Edited March 9, 2010 by QWK32

[Jetwreck]

I dont know the exact composition but it is some kind of material/canvas and resin mix. heat rating up in the 250-300 deg C range. Used for components in large industrial ovens. Granted they are constantly used in temps above 200c the better part of each day, which would be more extreme than an engine bay. But have found that if i'm not careful during installation it will damage easily. The most frequent failure i see is with phenolic wheels, sometimes only lasting a couple months before they fall to bits.

I may be familiar with a different grade of phenolic than what your using though, i don't know. I knew you guys would have looked into it, i was just interested in your thoughts/findings, as the phenolic i'm familiar with i would not be comfortable using anywhere on my engine.

Yeh our application is a little different....our temps will only probably ever get up to about 5C-30C on non traffic roads and 60-70C in traffic....the heat range of the 16mm thick canvas product we are using is good for 250-300 deg C and its a non moving part.

The Spacer has all been pretty much match ported to the intake manifold with a CAD drawing.

P.S. Correct me if I am wrong Andy/Cam

[andy65b]

Yeh our application is a little different....our temps will only probably ever get up to about 5C-30C on non traffic roads and 60-70C in traffic....the heat range of the 16mm thick canvas product we are using is good for 250-300 deg C and its a non moving part.

The Spacer has all been pretty much match ported to the intake manifold with a CAD drawing.

P.S. Correct me if I am wrong Andy/Cam

may be just get up to 80c but I would not think more.

[iamhe77]

So we installed another of these phenolic runner spacers on my mates stock M35, unfortunately he does not frequent this forum but this is what he had to say (cut and pasted from an email in which I asked him what difference, if any, he has noticed with the addition of the spacer).

Went to the airport and back last week, then to Leongatha (waved to your house on the way past) on good friday and up to Corowa (NSW border) for the weekend....

10.4 l/100km.. That is the lowest I have ever had, even lower than when I collected the car and drove back from Sydney like a wuss, because I had no numberplates..

688 kms range... Could easily have done over 700 as refuel was only 72 litres...

As stated, car holds 5th gear much better and there is off boost performance.. Very happy thanks!! And engine cover is happily fitted with just the rear nuts holding it on..

will try to get some longer studs for the front sorted out.

Thanks again.

So it seems that the recurring theme from this mod is greater off-boost performance, more torque and the car holds 5th much better while cruising

If interested, please either post in this thread or PM either Andy65b or Jetwreck.

Edited April 7, 2010 by iamhe77

[bbenny]

Really interested in this spacer guys.

Just curious if anyone has done any before and after dyno runs yet?

[scotty nm35]

I did but I changed injectors at the same time. Gained 16kw. I wish I had done one mod at a time but I needed the spacer due to the longer injectors.

The idea is to increase the speed of the airflow into the cylinder, especially in the midrange, filling it quicker, right? Smaller ports will help with this as well as longer runners. It just goes against popular belief unfortunately.