Jump to content
SAU Community

Recommended Posts

So we have a coupe of M35's that have been highflowed and tuned with Haltech Interceptor or eManage Ultimate and a few highflowed but running a stock ECU - like mine.

With a 3" turbo back exhaust, it would seem that 200awkw at 19psi (?) was the limit. So we started looking at what could be restricting it.

I looked into the possibility of purchasing the TEPS suction pipe, as their design seemed totally logical and was a direct route from the airbox to the turbo as opposed to the excessive OE design which has 3 bends and 3 different pipe sizes as well as a resonator. I, and a few others held the opinion that the intake was a restrictive factor and part of the reason that 200awkw could not be surpassed.

During this time, "Scotty nm35" decided that making a suction pipe was the only way forward for his car.

(You can find his first attempt HERE)

After a bit of discussion, we decided to make one up for my car as well.

Anyway, the first attempt with the "mk2" design started with the twisty bend from the turbo and, being aluminium, obviously required heat wrapping.

It also required gentle bends for easier airflow and the internal wall needed to be as smooth as possible, so a fair bit of sanding was done to ensure this was the case.

(so you think that C34 turbo's are in a tight spot? Also note that the a/c pipe needed to be bent out of the way - worrying while bending, but all good)

IMG_1550.jpg

Next up, we decided to experiment a little. I wanted as little disruption to the aluminium with smaller silicone joiners than the Scotty's original design.

We also decided to try to implement the OE A/F sensor pipe so the air would be a straight as possible over the sensor. Thought being that this would aid idle and possible stall concerns.

With the angles worked out, this was basically what the result was (3 small silicone joiners, the OE A/F sensor pipe and a "lobster" bend where the breather pipe (and later the BOV return pipe - see issue #2) connect in.

IMG_1555.jpg

Again, the internal wall needed to be as smooth as possible with the silicone joins as small as possible

IMG_1556.jpg

Connected to bottom section and heat wrapped.

IMG_1560.jpg

... and with the breather tube attached and the BOV return barb not yet hooked up.

IMG_1563.jpg

Lastly was the bend from the airbox to the pipe... again, this required heat wrapping as it felt like a radiator top tank while it was bare aluminium but also needed to be removable to get the airbox out for panel filter cleaning. (note. Heat wrapping was re-done after this pic)

IMG_1566.jpg

You can see the extension on the BOV return pipe in the above pic which allowed the lower half of the pipe to be maneuvered to connect with the barb on the intake pipe.

Not 100% necessary, but I much prefer it to flutter... and the wear that would have to cause on the turbo.

End result in a very, very dirty engine bay :cool:

IMG_1576.jpg

Issues!

#1 the first issue with the design was that the suction pipe, being aluminium, the size it is (76mm) and so close to the exhaust manifold, would get too hot to touch. Couldn't be good having the turbo sucking in scorchingly-hot air.... Hence all the heat wrapping.

#2 found that the OE BOV cannot be left venting to atmosphere. this leads to MASSIVE fuel consumption (4.3km/L over 2 days with mostly freeway driving) and also stalling problems when pulling up to an intersection. So I blocked it off which ended both problems but gave the car some very loud "flutter" and a pug that kept being ejected from the BOV pipe and stiting next to the turbo... which meant instant stall, and required fishing out.... which meant some very burned fingers :P

Benefits!

#1 Noticeable ease in which the car accelerates and builds revs (even with the OE dump pipe still on).

#2 More power. Definitely more power.

#2 Whilst the car does use more fuel when accelerating at a decent rate, economy has increased considerably. Particularly whilst cruising!

A/F ratio changes when the stock ECU finished it's "re-lean" period and is now 14.5, which is what most tuners aim for I am told.

So all up I am very, VERY happy.

My car makes power much more easily, I have MUCH better fuel economy thus far (will continue to test as the batch of fuel may have had something to do with it), not noisy (which is a plus for me), and my car no longer makes that annoying "wwWO!" sound that it did before, which I was told happened when the turbo doesn't get enough air and was the same sound as when GTR's such their intake pipe shut.

MASSIVE thanks to "Scotty nm35" who put in a TON of time and 99.999999% of the work ;)

Maybe you should price it up for others mate..... :)

Edited by iamhe77
Link to comment
https://www.sau.com.au/forums/topic/296472-fisher-mk2-suction-pipe/
Share on other sites

  • Replies 66
  • Created
  • Last Reply

Top Posters In This Topic

Kit would be a bit trickier.

Problem being that mine and Scott's turbo's are indexed differently to both the OE and each others!....so going off ours will probably not fit other M35's...

Damn, you posted this while I was excitedly typing!

If Scotty nm35 was interested, maybe it could be supplied with the turbo flange not welded on, clocked in, marked and finished welded by the fabricator of the purchasers choice? A single weld like that, would only be a small expense.

Just a thought.

Damn, you posted this while I was excitedly typing!

If Scotty nm35 was interested, maybe it could be supplied with the turbo flange not welded on, clocked in, marked and finished welded by the fabricator of the purchasers choice? A single weld like that, would only be a small expense.

Just a thought.

True. The difficulty is with the angles and the (very) limited space.

Even with my car there, it was difficult getting the correct angles... even when we did have the correct angles, the middle section moved slightly when the bottom clamp was done up!

Pain. In. The. Arse.

Having said that, if there is enough interest....

(not dobbing you in for anything Scotty :P )

I dont even remember you taking so many pics Cam. :P

I can definitely make more, although I am just a lowly backyard fabricator. There is a full 2 days work involved for each, which blows the cost out a bit.

No dyno run yet but there is definitely more poke, so it looks like the 200awkw limit may have gone. I will post up a graph of before and after fitting this week hopefully.

:P I forgot you were going to upgrade to the "mk2" design... or will you be improving the design it be a mk3?

Also wanted to post a pic with the stock intake lying on the ground next to the "fisher" intake... just to give people on here an idea of the difference between the two.

Think you could do it while you have yours out?

Got a few other pics, but I felt they were not required :D

Edited by iamhe77

Stockie and Mk 1 intake. I had an idle airflow meter issue with this one as it didn't use the standard airflow tube, and the meter was mounted on the bend.

Cam's intake had no such issues once the blow off valve was plumbed back in.

post-63525-1258363270_thumb.jpg

post-63525-1258363316_thumb.jpg

post-63525-1258363358_thumb.jpg

Thanks mate.

Quick update on economy.

Just filled up today with a week of around town driving (including daily hills for those curious Sydney owners and quite a number of "test" launches ;) ).

62.84L

558kms on the odo

= 8.9km/L OR 11.3L/100kms

Will see what the highway economy is like when I get a couple of hours to go for a cruise.

Edited by iamhe77

So all this is without any aftermarket ecu? you say the factory computer did this all by itself? I am shocked. I always thought that once you put an exhaust/turbo on etc that the factory computer would never be able to deliver good results...(due to the factory tune being so specifically customised to the standard setup) - I am glad to be proven wrong :wave:

So just by opening up the intake a little more you've achieved both more power and more fuel economy...I love it :(

Yes, yes, no.

Yes I am only running the standard ECU.

Yes, it did this all by itself

No, we did not open the intake a little. The hard pipe to the turbo is massively restrictive and going from a rectangular inlet of roughly 40x20mm (let alone the bottom bend) to a 76mm diameter pipe is a fair increase and one that we thought might play havoc with the A/F mixtures.

And yes, Steve. I love it too!

(and was probably more surprised than anyone :wave: )

Edited by iamhe77

The 80mm Mk 3 intake works fantastic, no stalling or mixture issues. Now to find some funds for a dyno run. :P

Cost me around $300 in materials and 2 full days. Each one is uniquely fitted so if anyone wants one they will have to drop the car to me, I cant fit off my car as it means mine is off the road for 2 days. (unless somebody has a spare motor lying around I can work off.)

post-63525-1258938543_thumb.jpg

Edited by scotty nm35

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...