Pic of J-boot delete.

[wild man]

There was a thread that I can't seem to locate now, about replacing the stock air box with a behind-the-intercooler "cone" filter and an adapter on the AFM. I had mentioned that I once used a setup that deleted the air box AND the J-boot, in favor of an MAF style intake routing. I think it was cold-running 924 that requested a pic of the setup. There is no pic of it while it was on the car, but Igrabbed as many pieces of it as I could find, and put it back together for a pic that I took today. Here it is:




What is not visible in the pic is the 2 holes in the AFM-to-turbocharger rubber coupler (formerly a charge-pipe-to-throttle-body coupler). The holes were for the various (4, I thinK) small-diameter hoses that feed into the intake. I used 2 T's to reduce the # down to 2, from 4. This was the most difficult, ugly, and problematic part of the setup, as these 2 connections stuck down into the intake a mere inches away from the compressor wheel. I also had to flatten the charge pipe somewhat, for the AFM to fit under it. All of the issues I had with this setup were due, in fact, to space/fit issues. This setup might be feasible if the small diameter hose issues could be properly addressed. I do recall sweating 2 1/2" copper street elbows together at close to 180 degrees, to get one of the hose angles right. Like I said, it was tight, and ugly. But it did work.

[running_cold924]

ah, cool, thanks for the pic. i just needed a little idea of what to do and how you did it

[wild man]

No problem! Just remember that you will need a 3"hose adapter on the front side of the stock AFM. The one on mine is DGT part #1-285-703-007. Most likely german, I would presume, because it was bosch OEM, on an 88 T-bird turbocoupe. And I think that only 1 of the 90 elbows that I soldered together was a street elbow.

[vanosman]

I sold my MAF and went back to steady OEM flapper with cup chips.











any idea about these configurations by Broadfoot using stock flapper AFM ?

[TThom]

I see little point deleting the factory airbox when running a stock K26, which doesn't create enough vacuum to be restricted by the rectangular section of the stock AFM/airbox.

Looking at the pics above, and still considering the small rectangular section of the AFM through which intake air goes, I just don't understand the effort - if people have to keep the stock AFM they may as well keep the stock airbox as it provides the most fresh air possible to the turbo.

[vanosman]

K26-8 Garrett hybrid, straight 3" pipes.

How would one use a "Larger turbo" with stock flapper AFM ? ? ?
Please explain how that works , a 3" turbo with stock AFM ??


My old MAF cone relocated did respond better than in stock area, sold the piggyback thinking someone would have the old Lindsey relocator config, seems that old design was thrown in scrap yard with Apollo Moon hardware and Saturn rockets.

other folks that swear the ambient air is cold don't consider that first thing it hits is a heat soaked paper filter in a box you can fry an egg on, making IC work that much harder. Behind each headlight is very cold air.

I also have 3stage DEI intercooler spray kit installed with CO2 tank.

I plan to relocate my cone behind LR headlight duct if I can find someone brave enough to reply with some details how to get pipes to align.

[vanosman]

Originally Posted by TThom

I see little point deleting the factory airbox when running a stock K26, which doesn't create enough vacuum to be restricted by the rectangular section of the stock AFM/airbox.

Looking at the pics above, and still considering the small rectangular section of the AFM through which intake air goes, I just don't understand the effort - if people have to keep the stock AFM they may as well keep the stock airbox as it provides the most fresh air possible to the turbo.

I'm going for cold air velocity with ported head. A big flow 3" turbo is NOT what i have, nor a stock k26-6 and pipes.

A stock 951 in winter is MUCH faster than it is in summer FASTER THAN heat soaked intake at stoplights. (NOTHING TO DO WITH CFM FLOW or VACUUM)

getting ambient air from stock config is swell, but the box and filter inside is roasting, once its cooked the box enclosure keeps it cooked for awhile, even after you pull onto highway.

If Porsche designed that same box in the nose then its no problem with heat sink.
And the box traps water from wheel fender, oiled cone will get wet, yet will not puddle as stock snorkle or box (FACT)

Those chopped wide snorkle mods is neat mod, but it won't address the AFM restriction (THAT IS CFM FLOW problem, I don't care about this restriction, since my old MAF barely made a flow increase seeing that the IC has stock inlets and IC hard pipes same ID and kinks, I would think to increase flow one would have to change IC inlets first, manifold intake, then rest of the pipes and meter.

A MAF won't do, sinks resell value like most tuning kits and race parts. My friend make a bit more HP with big flow head and turbo, but he lags behind in 0-70, drinks gas with 55lb inj and costs was + $4000 to crank out maybe 30hp at top end 70mph -170mph with less reliability, less MPG, less resale appeal.

I rather have +30hp in a Millege CF intake manifold and larger intercooler, a turbo wrap, and a spare C02 bottle, a Quaiffe LSD, etc

[TThom]

Originally Posted by vanosman

other folks that swear the ambient air is cold don't consider that first thing it hits is a heat soaked paper filter in a box you can fry an egg on, making IC work that much harder. Behind each headlight is very cold air.

Why should they even care about actual intake temp if the engine doesn't knock under WOT at 18psi with generous amounts of timing advance?

I never had any issue when using good chips (MaxHp) and the stock AFM/K26#8/airbox on the 2.5L engine, never got any water or whatever in the airbox, though the car used to see pretty poor weather back then.

[vanosman]

Originally Posted by TThom

Why should they even care about actual intake temp if the engine doesn't knock under WOT at 18psi with generous amounts of timing advance?

I never had any issue when using good chips (MaxHp) and the stock AFM/K26#8/airbox on the 2.5L engine, never got any water or whatever in the airbox, though the car used to see pretty poor weather back then.

With that logic, just remove the intercooler and advance the timing even more ?


Does your V8 951 have forced induction ?

I'm using burned CUP chips from Porsche matched to the K26-8 .

How do you know if you got moisture in stock snorkle and airbox, did you open it up after driving in the hard rain ?

[TThom]

Am I even supposed to reply to this?

[vanosman]

Originally Posted by TThom

Am I even supposed to reply to this?

so you have an 8valve 951 3.0L , not a v8 LS1 conversion ?

I thought all 951 were 8v, including 968RS.

You say don't worry about cooling to reduced detonation or make power, just advance the timing ?

How does one advance timing with Cup chips and stock AFM ? Chips are already advanced. I don't have knock.

So you believe the stock air box is cold as ice and has little heat sink, just advance timing to reduce knock and forget CAI config with AFM because factory is best ?

Having had a CAI cone MAF before, I would have to disagree. I never bothered to measure the heat, but many have claimed behind radiator is +165.

behind headlight duct and turbo heat wrapped, maybe header wraps would cool things down enough to help the stock IC and sprayer.

It gets +107 here in summer, power drops about 30hp

[TThom]

Originally Posted by vanosman

You say don't worry about cooling to reduced detonation or make power, just advance the timing ?

So you believe the stock air box is cold as ice and has little heat sink, just advance timing to reduce knock and forget CAI config with AFM because factory is best ?

Did I really say that? I don't think so.
I was saying that a cone filter won't make a difference knock-wise with the airbox/snorkel with chips such as the "Cup 290bhp" which, unless you know already, feature a very agressive timing curve in higher RPM compared to stock or even aftermarkets such as Guru/MaxHP (etc).

Originally Posted by vanosman

How does one advance timing with Cup chips and stock AFM? Chips are already advanced. I don't have knock.

...and you wouldn't get any more knock running the stock airbox/snorkel.
The original "290bhp" Cup fuel/timing mapping done by Snobeck for the 1990 Cup series in France are knock-safe, even in very hot weather, but that is when running a stock K26/8 turbo, not some Garrett/KKK hybrid with, I assume, a different compressor map, which seems to be your case.

[vanosman]

Originally Posted by TThom

Did I really say that? I don't think so.
I was saying that a cone filter won't make a difference knock-wise with the airbox/snorkel with chips such as the "Cup 290bhp" which, unless you know already, feature a very agressive timing curve in higher RPM compared to stock or even aftermarkets such as Guru/MaxHP (etc).



...and you wouldn't get any more knock running the stock airbox/snorkel.
The original "290bhp" Cup fuel/timing mapping done by Snobeck for the 1990 Cup series in France are knock-safe, even in very hot weather, but that is when running a stock K26/8 turbo, not some Garrett/KKK hybrid with, I assume, a different compressor map, which seems to be your case.

CUP K26-8 is NOT same as K26-8 1989, this is confirmed that the hot side has bigger wheel, yet my 1989 cold side has larger milled to fit Garrett, true mine is not exactly Cup Turbo with my Cup Chips.

290hp seems low with 111oct, 18psi . The goal is making torque with velocity rather than big flow with Lindsey Stage II head, my 3" test straight pipes, 3bar AFPR, cup fly, cup clutch, KEP pressure plate and Quaiffe LSD, 18" twists, to put that torque down to rear wheels.

I'll get a dyno before and after C02 sprayer.

Now the stage 1 C02 fuel bar would reduce detonation ? Drag racer cheaters use soup can and copper lines and dry ice to cool the petrol.

Also have stage 2 CO2 section between oiled cone and AFM witch measures ambient temp unlike my old MAF 3.

I saw some guys with big IC install temp guage on the IC pipes.

I think the IC inlets is the major CFM restrictor. But with all that changed, the TB is still stock and is said to be 130% as big as it needs to be already.

I think I'm squeezing nearly all I can from this hybrid k26-8 and flow matched stock Bosch inj.

So I'm focusing on the intake reconfig and IC.
Curious what C02 would do to engine, since the cone is behind radiator and IC sprayer, I've never sprayed at WOT for this reason, it would prob like Nitros but that stuff is combustible and cost 3x more than C02 from a welder and uses different tank flange. Would it just rob HP or choke the motor if 5 second C02 blows over the cone @ WOT ? PCA guys debate inert gas and physics all day, many opinions, I rather just relocate the cone behind the LR headlight duct so I can hear the spooling whistle again, or would the flapper silence that in any location ?

How were your physics grades in school ?

[Pete R]

sorry to jump in on the fight, but some thoughts. You could use paintball gun canisters for your Co2 supply. fairly easy adaptation. I rent a 75 lb "welding tank" and fill 16oz paintball air off it. Given that Co2 is also used in fire extinguishers I'm thinking it may suffocate the "fire" if enough was sucked into the airbox. What about using a water sprayer on the ic like Subaru sti's. You could proably adapt that real easy therostats and all.

[TThom]

Euro Cup cars and later turbos (250bhp) always had the same K26/8.
The "290bhp" was the official figure for 90' Cup cars though most produced slightly more than 300bhp.
I'm not discussing Canadian Cup cars as I have no experience with them.

I was pointing out that the airbox/snorkel has always been a proven and effective solution on Euro Cup cars, since they were tuned with it yet with a high amount of ignition advance in higher rpm for the ones for the 1990 trophy.

Since some seem to be dragging my point out of focus it's quite tempting to think that my physics grade in school were probably higher their grades in literacy and text understanding.
However, I'm willing to try again.
The airbox was obviously shaped to accomodate the rectangular flow section of the AFM, which has been a Bosch offering on VAG cars well before the 944 turbo came out.
It is also a documented fact that a stock K26 (6 or 8 regardless) doesn't create enough vacuum pre inlet to justify using a flow section larger than the AFM's.
It is also a documented fact that using the airbox/snorkel in place of a cone (regardless where it's located in the engine bay) will provide fresher air to a stock K26 turbo than a cone filter set up.
So basically : cone filter + AFM + stock turbo = some work and expense resulting in IAT increase.

Now let's replace the stock K26 for a turbo that flows a lot more. There we are limited by the AFM flow section which results in increasing the vacuum pre turbo inlet, thus affecting turbo performance (and possibly increasing oil suction out from the AOS line)
So, basically : turbo flowing more than stock K26 + AFM = some work and expense resulting in counter productive vacuum increase pre turbo inlet, regardless of cone or airbox since the rectangular flow section of the AFM remains the restrictive part in the pre turbo part of the intake line.

[vanosman]

Originally Posted by Pete R

sorry to jump in on the fight, but some thoughts. You could use paintball gun canisters for your Co2 supply. fairly easy adaptation. I rent a 75 lb "welding tank" and fill 16oz paintball air off it. Given that Co2 is also used in fire extinguishers I'm thinking it may suffocate the "fire" if enough was sucked into the airbox. What about using a water sprayer on the ic like Subaru sti's. You could proably adapt that real easy therostats and all.

$15 for 10lb tank at welder

Paintball guys cheat people, I weight the tank before and after.

[vanosman]

"Lindsey Racing felt that it would be beneficial to retain the ceramic liner if possible so Lindsey Racing has been testing different combinations on the 951 head to try and increase the port velocity without significant loss to the flow numbers. The problem is that the ceramic liner that is inside the exhaust port on the Turbo head cannot be altered, so porting the exhaust cannot be done. There is an alternative and we have discovered what that is. We now have found a combination that the exhaust flows 185 CFM with the velocity increased from a miserable 390 to an impressive 566 FPS! That is a 45% increase in velocity with only a 3% loss in flow rate!
Imagine what will happen to the Turbo when you hit it with hot exhaust gases that are moving so much faster"


I'm NOT concerned with a little loss in flow as I can keep my hybrid BB 52 trim Garrett K26-8 and Bosch inj and pump, keep cup chips w/o a piggyback MAF.

If I spent $5-6k replacing those performance parts for more top end flow, the car would be less likely to sell fast. 951 would be a "DYNO QUEEN TUNER CAR" like your monster 3.0L .

In distant future, I'm looking at Cayman S and their $7k turbo stage 1 kits making 11.9@1/4m & 11.2 on a stroker. I don't want to be stuck with a Monster 3" turbocharged 3.0L 951 30yrs old that won't sell fast with some MAF tuner or $2k MAP with 72lb inj and 3" inlet turbo with some welded custom manifold intake.

+400rwhp on 951 = tranny repairs & head gaskets

Some Cup guys i know call them K26-9 because the hot side is bigger than 1989 stock, as the Cup Chips are diff than 1989 stock. ( PCA Tech, Panorama Mag)
I sat my hybrid next to 3 other K26 and K27, he has a cup car with magnesium wheels.

I also explained that 1989 was same as cup as well, seems hot side wheel is bigger INSIDE i learned.

[Pete R]

Originally Posted by vanosman

$15 for 10lb tank at welder

Paintball guys cheat people, I weight the tank before and after.

yeah, some are sneaky... but if you have a 16oz tank you only fill to about 15. Once the co2 warms and expands a bit it take out the burst valves pretty easy if topped right off. If you use enough co2 it would propably be most cost effective for you to rent a 75lb tank ($4 a month for the tank and $50 a fill), buy a cheap fill station, and fill your own smaller (paintball)tanks to use in the car, but anyway. have you done a co2 set up in a car? I'd be interest to here how it worked out. sounds interesting

[vanosman]

Originally Posted by Pete R

yeah, some are sneaky... but if you have a 16oz tank you only fill to about 15. Once the co2 warms and expands a bit it take out the burst valves pretty easy if topped right off. If you use enough co2 it would propably be most cost effective for you to rent a 75lb tank ($4 a month for the tank and $50 a fill), buy a cheap fill station, and fill your own smaller (paintball)tanks to use in the car, but anyway. have you done a co2 set up in a car? I'd be interest to here how it worked out. sounds interesting

I disconnet kit in late Fall, it gets cold here then traction is issue and more cold air = more tire spin . Only spray IC in spring and summer

[TThom]

Well vanos, I understand your point of view.
I suppose "you pays your money and you takes your choice", and I'm happy with my two 944, they are now "old" cars but they are pretty uncommon these days and I can do most of the work mysef, which is important to me.
The turbo is no dyno queen, it's a relatively pragmatic set up and I rack up 12k miles per year in all weather as I see little point drowning loads of money in these cars and not using them.

I'm sure you will enjoy the Cayman, they are great cars.