Tony D
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Posts posted by Tony D
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Considering option #2, consider the responsiveness of the engine below 3500 rpm before the cam starts working.
Why doesn't anybody complain abbout 'camshaft lag' in this case, yet 'boost threshold' is some sort of terrrible bugaboo...
You hit it on the head indirectly: because the power is so non-linear. When you hit boost threshold (and on a T3 it will more likely be 2500...) the power is so much more than an N/A's linear delivery.
The conclusion: the engine is being driven wrong. If you keep a turbo on the boil, same as a cammed engine in an N/A you end up with none of the 'non-responsiveness' that uninitiated drivers feel when driving a turbo in a lazy manner, below boost threshold two gears too high for the speed being driven.
The thing is on a turbo car it's easy to drive that way because of the torque available whereas the N/A will be a miserable, boggy dog till you get up on the cam.
Camming and flowing a Turbo car will result in power that pulls easily into the 7000+ rpm range on an L-Engine. It's just most take the lazy way out and boost a stock engine---and as a result end up with something that barely revs above 5500-6000 due to camshaft limitations.
Use the right cam in the turbo application, and your turbo masks the cam's inefficiencies below 3500 by adding massive torque compared to an N/A of even 10:1 cr, and when you come on the cam at 3500 the feeling is linear progression just like an N/A setup.
Problem is, most people over turbo their applications so that boost threshold is above camshaft torque peak---so you have 'mismatched components' that compound a poor situation. Get it set up correctly so the turbo is boosting before you reach a camshaft peak and simply bypass excess exhaust gas at the top end for the pull to 7K+.
Vote for Turbo, here, obviously.
But if the 5M is cheaper, and you already have it....logic dictates that is the way to go. Who cares what provides the motive power, just so long as it goes? It's a flattish Valvecover, grind it off and put some stick-on Nissan decals on it and get people thinking...
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The webbing acts as a heat dam to prevent heat from rising to the upper portion of the engine bay where the fuel components lie.
The early ones didn't have it, every later one did....ever think why?
I mean, would Nissan pay all that money to add aluminum to a manifold that didn't need it?
Before rethinking things for cosmetics sake, think about the practical rammifications of the modification and why it was put there in the first place.
If you want the exhaust manifold heat out, why not supply a proper duct to exhaust it out, using the webbing as it stands?
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You can do it in-place. Disconnect the wastegate rod from the actuator arm, and see if you can get the arm on the turbine hot-side to move. Sometimes soaking in Kroil or PB BLaster works to free it up, otherwise further disassembly is required.
It wouldn't be the first time a linnkage rod was bound up as well. Removing the actuator completely is a simple matter with two 13mm bolts and a needle nosed pliers for the clip on the hot side.
That little rusty arm should flop around pretty freely once disconnected.
If it does, the possibility of the flapper being broken off comes to mind, and as stated above, 'further disassembly maybe required at that point---if the popoff valve on the manifold is not leaking boost off.
So there are a few things you cna check before having to remove the turbo for inspection. Worth the time to check first, doesn't hurt at least...
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"I've never messed with carbs your right on that account but I have plenty of friends that do."
That was the whole gist of the post. Please don't make such statements and mislead people when it is clear from the statement the access is limited. The 'you don't know me' argument is moot. We are trying to foster an environment of cogent discussion of the topic, and not perpetuate myths.
Your post was just a tad on the 'heresay' side of the situation. I.E. not from firsthand experience, nor close firsthand observation. Try to limit that kind of commentary, as it's anecdotal, and not relevant.
I'm not moderating you, but if you think this board will let statements of limited technical veracity slide, you've a lot to learn. My statement was simply that I wouldn't consider 21+ psi as 'limited'...
If you want to talk about something with water or methanol injection, then the number is QUITE a bit higher.
I was talking about cars set up with a Holley Draw-Through, bolted to a turbo, blowing into the intake of the head. No water injection nor methanol injection supplementing it.
Hell, my 73 was running 17psi daily in SoCal for years without supplemental anti-detonant (which as you stated can be considered a poor-man's form of intercooling)....but then again so can excess gasoline. In which case ALL forms of draw-through are inherently intercooled...
And the statement would be then more true that blow-throughs are limited in boost unless they are intercooled.
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What I did on my 73 was use an Electrically Controlled Hayden Fan Controller. I waited for a HOT day (109F), and then got the car out on the highway---obviously the fan should NOT be running at that point on level ground and cruising. I noted where the thermostat was keeping the car (160 degree Chevy T-Stat). I then took the car off a frontage road, and put the car in fifth gear, and sloooowly let the car slow down till I saw the temp rise...then sped up slightly. This happened to be right around the lug-point on my car---around 35 MPH in fifth. I set my fans to kick on about 10 degrees above that 'low lug point'---it ended up being around 180 (even though it was a 160 t-stat!). Apparently that is the slowest I can drive and not have the car continually spiral up in temperature. So the fan kicks on at 180-185, and will shut off at around 170-175. I can watch this in traffic, and going down the road. Running on the freeway, the engine stays much closer to 160-165, when I pull down onto surface streets, the car will run 165-175, until I hit a stoplight. I can watch the temperature rise, and then the fan kicks in. As the fan does it's business, I can watch the needle on the gauge go back down to the cutout point, and can hear the fan shut off. It really gives me piece of mind that it operates in two distinct ranges. If it's climbing on the road I suppose eventually the fan may come on, but it hasn't done so thusfar. And in the stop and go of downtown L.A. the on-off keeps me from overheating.
To my choice of thermostat: I figured the cooler everything was under the hood, the better. I tried this same setup with a 190 t-stat, and the car would surge and buck from vapor lock or whatever. But with the 160 in there, everything is so much cooler to the touch (intake manifold, fuel lines, etc) and I don't get any of the surging I got when running the hotter setups. Basically, as long as I'm moving forward in clean air, I have never heard the fans come on, and the car stays cool within reason. But slow way down and stop, and the fan will cycle, just like an OEM setup.
Carbbed Car, btw.
hope that helps you with the setup. It has worked well for me since about 91 when I changed to the twin Hayden 10" fans, from the old 16" Japanese Refrigeration Condenser Fan I formerly had on there!
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Yeah, buy a Fairlady, they are out there and cheap enough.
The pedals on a 'converted' RHD setup bend the wrong way (towards the tunnel on the LHD, but when on the RH side, they point toward the door, and just don't line up correctly...)
All the bracketry regarding electricals is identical between Fairlady and comparable model LHD---the harness is longer for the insturmentation, but nothing big there to swap...
I'd still buy a Fairlady, it's going to be cheaper, and be right. They are lighter anyway, so Fairlady Z's make better starter vehicles for project racers anyway.
Matter of fact, if you are willing to travel, there are probably several Fairlady Z's in CA within a 6 hour drive.
The ZX is a much more involved conversion than the S30. For a ZX, I'd get a Fairlady DEFINATELY. For an S30, the parts are fairly easy to do the swap, but on a ZX, run away! Run Away! Fairlady Purchase is THE way to go in that case!
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I have to agree with lbhsbz, look at it as a kit!
My first Harbor Freight Tool finally took a dump last year...never oiled it, ran it with dirty air, ran water through it, finally gave up the ghost in 2006.
I bought it for $9.99 in 1986. 3/8" Butterfly Impact Wrench.
My Dad was buying their stuff when they were selling the tools separate from the motors (some import restriction, methinks) when they were having parts and machines made in TAIWAN. His stuff is of VERY good quality, and was all bought in the early 1980's. I'll probably get it when he passes away, gawd knows my bro isn't mechanically inclined...
Anyway, back to the "kit" comment. I noticed when they started getting stuff sourced from Mainland China, the quality started going south in external finish, etc...
I now disassemble everything when I get it home, and repack the bearings, etc. In some cases, I will replace the bearings with good SKF or NTN stuff I get from King Bearing. There WAS a time when the die grinders came with the SAME internals as a Snap-On Die Grinder (NTN bearings included!).
I also second the 'get a good chuck'---I knocked their chuck out and use the German Albrecht Keyless Chuck with my MT-2 Adapter on it. I can always stick the collet adapter on it when I need to use it in the Bridgeport.
For the money, if you take a few little preventative steps before you put it into service, or very shortly thereafter, you will be rewarded with something that will last a LONG time.
True, there was a time when you didn't HAVE to do this with their stuff, but they went from Taiwan to Mainland, and it shows.
I do work there (China) and that convinced me to not trust anything out of there just yet. Taiwan I trust a LOT more than mainland China at this point.
Now my Bridgeport: $1250 for a J-Model with complete tooling and a shaper attachment was NEW in 1975, and has been in a welding shop gathering dust and cutting slots in aluminum since he bought it from the original owner in 1980. For the price, nothing I could buy at HF could compare. My kid will get this when I die. It will still be tight and working great. If you can find old 3 phase American stuff and buy a conversion motor for single phase, it's the greatest deal on the face of the planet. I bought a 6" hydraulic horizontal band saw for $25 (scrap value) and spent $200 on the Frame 56 single phase motor for it's conversion and absolutely LOVE it! Big, heavy, and made in Kalamazoo Michigan.
Now, that Buffalo Drill Press.... Buying things intended for an overhead belt system may be more than most want to tackle. I figure it will look good painted up and just sitting there with the 1 3/4" drill chucked up in it! LOL
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i've see draw through work well but boost is limited by lack of intercooling (its impossible, not safely anyway)
Not that I disagree that a carburetteed turbo is a poor idea, but exactly how can you quantify that statement of "boost is limited"---what constitutes limited? 21 psi? Because I've seen plenty of Holley Drawthrough non-intercooled turbo setups on L-Engines run those kind of numbers (and run loooow 11's in a full bodied S130 in fact...)
So saying you are 'limited by lack of intercooling' is probably a bit of internet parrroting than speakingfrom firsthand experience, at least that's my guess.
I just want the record straight that at least in my mind, 21+psi of boost is not 'limited' by any stretch of the imagination!
EFI, that's the way to go for drivability.
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What I suggest people do is search out the research done by piston manufacturers and the OEM's regarding TBC Coatings.
Of particular interest, if you can find the stuff, is extensive experimentation and documentation of the results done by Keith Black Racing Piston's Chief Engineer John Erb. He has published several papers on the subject, some of them pamphlets for the KB Piston Customers, some through other sources. You may find him quoted on this subject, as well. This is regarding combustion chamber coatings, but he goes into pistons and piston crowns as well.
I spend time at this shop, that is where I got some contact with Erb and his propaganda on their behalf---
http://www.techlinecoatings.com
Their Tech Articles Section is worth reading.
These coatings are what we use in our Screw Compressor Overhaul Program, though the engineer in charge of that program formerly used them in his Top Fuel Blower Rebuild Business on the East Coast, as well as being a distributor for Swaintech (they are in NY).
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"but it did bring to light that the ceramic coating he used didn't hold up to the cylinder heat."
No, that is not what it showed at all! And that is my point entirely.
Poor Conclusion drawn from poor anecdotal evidence and miserably researched.
Like I said, an HKS Metal Head Gasket Blows Out under Detonation, and Conclusion: They're junk, they don't hold up.
Same type of statement being made about coatings from Austins post.
Bad Decisions made from Bad, Incomplete, Anecdotal "Research".
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TO solve this once and for all, run a wire from your fuel pump relay, and install the three-wire heated O2 sensor from a VG30 (Z31).
The car will be able to go into closed-loop mode after about 30 seconds, and will STAY in closed loop mode MUCH LONGER. The problem is the good flow will let the single wire O2 sensor cool off.
This is how I have my MS wired, and this is how I've wired many other ZXT conversions using the stock electrics. I realized long ago that a heated sensor makes for MUCH better fuel mileage in them and never realized why. Someone did some scoping and testing, and found that once the ZXT ECU goes into closed-loop mode, it will stay there at idle and low speeds until the single wire unit stops switching. This usually happens when it cools off. If you run the heated sensor from the 86 Z31T (I think that's the model I specified at Pep Boys) the sensor stays heated, and on closed loop much longer. It screws right in, no problem (same turboon the Z31, slightly different downpipe, but the O2 sensor screws right in to the standard O2 sensor bung like the OEM unit. I will also work the same as your single wire without the heater hooked up, but I'd not run it like that)
I know my MS gets a switching signal and I can read voltages at cold idle (er... .9vdc on cold start enrichment...heh!) almost from the time I start it up.
Pretty simple test, and only one connectro to swap from the Z31 to plug it right in, as well as a few feet of wire for the heater power and ground leg.
Works Great.
Godd Luck!
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I think Austin's thread shows what you'll get from the coatings the best.
I think that's an wholly innaccurate assessment of the situation, and of Austin's commentary. For Austin's experience, I can show you documented situations from my own experience that totally dispell his experience. The terrible situation here is people are using anecdotal non-scientific assessments of uncontrolled and haphazard situations and making decisions based upon them.
Bad juju? Bad Science. Detonation puts off ALL situational assessments. And Austin's engine clearly detonated, as shown in his photos. If a metal head gasket blows when you detonate, do you then condemn all metal headgaskets as 'The best you will get from them' based on that one experience of abnormal conditions?
Put some effort into research, and the plusses are there. For 20psi, do you need it? Who knows...what kind of HP is that 20 psi going to make?
I can tell you one thing: Swaintech will be one vendor I contact for coatings on my Bonneville Engine Build. There will be others as well. They work.
But to say one anecdotal story out of a sea of controlled studies and racing series where coatings are used...making a decision or drawing a conclusion from that is the Bad JuJu---Bad Science indeed!~
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Jeff's motor has a different turbo. SO the cfm he had with his old turbo at 28 PSI is probably about the cfm flow of his new GT35R turbo at 20 PSI.
Jeff is making well over 100+ more HP at a given rpm point than his previous build. 415 to the wheels at 5500rpm and 23psi boost, versus 585 at an aborted 6300rpm run (power peaks at over 7000 on this build) at less than 20 psi. With a full run, the number was well over 100HP more at 15psi (somewhere around 465hp @7250 with 15psi or something like that). The turbo would not flow any more at that point, he couldn't get 28psi from it. At that point he was still thinking he 'needed' 30 psi to make his desired power. (And remember, this was a car with about a 2500rpm boost threshold, hammer it at any speed above 2500rpm, and the boost was INSTANEOUS to 23psi.)
The power point has changed as well, it's not just the turbo. The previous turbo was outflowed... incidentally he had 23psi exhaust backpressure pre-turbine when there was 23psi in the intake plenum with the previous turbo. That is a pretty free-flowing environment as it is.
What was changed was the camshaft primarily, along with flow increases on the exhaust ports...then the new turbo was sized based on projected horsepower expected. The build has exceeded expectations.
And there is still over 30cfm per intake port restriction that is EASILY removed, making for the possibility of much more power potential. But that, as it is, will probably never be seen on the street.
Not one that is paved with black stuff...
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Best bet is the 3.54. The turbo engine has way more torque, with a 3.90 you will go through the gears so fast you will end up spending more time shifting gears than winding through them.
Well, that all depends on what kind of tire height you have, doesn't it? Start looking at some of the taller tires that will fit on a Z, and it becomes VERY easy to turn a 3.9 into a 3.54 gearset using a taller tire setup. Same goes for having a 3.36 in a car with wide, super-low-profile tires, in reality the effective gear ratio is more near 3.9 in some cases.
I know my 3.9 in the Fairlady was far enough out of ratio with some 215's on the back that a Motorcycle cop pulled me out of the carpool lane to have a talk with me, and I only thought I was going 120kph... In fact, it was quite a bit more...
Gear recomendations without asking about tire height is grasping at straws. If you use stock-height tires, then maybe yes. But generally people here are running something of a performance tire/wheel combination, and that can have a GREAT effect on the gearing.
Personally, I really like the 3.7 gearset in the turbo cars running stock tire height. 3.54 always seemed sluggish out of the hole through first to me.
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niiice...
I agree on the Alpha-N blend for ITB's. The TEC2 system we had on the Bonneville car was a DREAM off-idle with the PAFFZ-Blend software---used a blend of Alpha-N and MAP as the RPM rose. Much smoother than the pure-MAP based system we have on the thing now, but this one give us more power under the curve for whatever reason. Much more torque.
You think 7cfm per throttle is bad, try a Six Cylinder engine total displacement of 1998CC's breathing through 45mm ITB's...with a Bonneville Cam set up for shiftpoints in the 92-9500rpm range! Talk about no vacuum signal at idle....or off idle for that matter.
Alpha-N is the way to go in that situation, for SURE!
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what about the coates spherical rotary valve cam shafts/head =)
Coates was contacted and were uninterested in any development of the L-Engine head, regardless of who was footing the developmental costs!
"They stopped returning e-mails" is one way of saying it.
I worked with Coates-Valved Powerplants, mostly Cat conversions from Diesel to CNG. So I was very familiar with their operation and what they are capable of when put into service over-the-road. Unfortunately, even when dealing with people who know our company was using their product, they were unwilling to experiment with short-run stuff. I was very disapointed, and so was JeffP.
BRAAP has my thoughts dead on---I deal with large industrial centrifugal compressors as a daily bread kind of thing. The BIGGEST thing we do to save a customer money is debottleneck their system so they can get the air to where they need it. Our compressors will work fine at 110psi, but the FLOW MORE at 85psi, and if that is all they really need for their plant tools and instrumentation, pumping it up to 110 wastes horsepower. Same with a Turbo driven off the exhaust...if you pump it up, you loose efficiency.
Think about CART engines. They continually drop the boost (last I heard they were down to less than 7#) yet their horsepower stays constant... They don't NEED the boost. The more you depend on building pressure to make horsepower, the laggier the turbo driven car will feel. Taking a drive in JeffP's car will feel like an N/A 240Z on steroids. Boost comes on immediately (about 2psi) and like when a 240 comes on the cam around 3500, Jeff's car makes big power starting around 3200 with a rush to the rev limiter at 73 to 7500rpm. He's afraid of the stroker crank at this point...he'll get over it I suppose. But the camshaft profile is more like an N/A grind and so is the power curve...just waaaay up there.
Build for flow through the engine, then size the turbo for the flow you will need.
Braap mentions 20psi and 500HP. This is JeffP's case exactly. He WAS making 415 to the rear wheels at 23psi on his last cam/turbo/head. On the current cam/turbo/head he's making over 585 to the rear wheels on an aborted run to only 6300 at just under 20psi.
Flow is good, boost is bad. You just need a shove through the valve, no need to cram it in there. If it goes in and out easily, you will make more power.
I just get frustrated when I see someone stating they want to build to a specific boost level, instead of a particular horsepower level, or performance benchmark. So you make 20psi. Like BRAAP said, are you making 400 with that, or 500+? Personally I'd like to be the guy making the 500+. if you prepare the engine for the flow, you operate at parameters that aren't so high.
FOR INSTANCE: How much heat does your intercooler need to take out at 30psi to return it to ambient? If you make your engine that will flow, and you only have to boost to 15psi to reach that point, doesn't it follow that you will more realiztically be able to meet ambient conditions in a wider range of conditions only generating half the heat to begin with? No matter what, compressing air to 30psi will raise the temp a defined amount. And compressing it to 15psi will be half that (if your compressor is sized accordingly in each case.) Taking out twice the heat will be more difficult.
There's just so much that adds up when you mega-boost an engine. For survivability, the lowest boost you can run to make the horsepoer you need is the ideal scenario. The less boost you need, the less lag you should have, the less threshold you should have, and things should generally be happier all-around.
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JDM: The Kei Cars are limited to 600cc's, and many are 550cc's. There are all sorts of turbos, superchargers, and compound turbo/supercharger setups on the little beasts.
I had a Suzuki Alto Super-Turbo when I left Japan. DOHC with a turbocharged, intercooled, roots-blown 550CC two-cylinder that made something like 74HP. Yeah, the car was reeeeeally small, but for two people it was all you needed. It was larger than the Cervo I owned. That one had a big bore kit to 600CC's, and ran a 48IDA Weber and special reed valves....would rev (two stroke) like you wouldn't believe. Hoot to drive!
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Yes, all the S30/GS30/S31/GS31 model Fairlady Z's had R180's in various ratios from 3.70 to 4.37...
Where in Wisconsin? I'm in Steven's Point for a job this week, but alas, am heading out to Buffalo via the U.P. (long route...lol) tomorrow morning.
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Why 30#? Properly executed, the car will make more horsepower than you will ever be able to hook up well below 20#...
Ask JeffP about how the right cam and porting wakes up a turbo engine!
He thought he needed 30# to reach his goal, and in reality he has surpassed it to the rear wheels before 20# judging by the last dyno run...
And that is on a stock single-Throttle Plate turbo manifold that kills 30 CFM on each runner. Wonder what power would be available with that additional flow by opening it up? How much is too much?
Boost is only a reflection of restriction to flow. Big boost numbers making big horsepower isn't a sign of precise engine planning, just forced induction working really hard to make the power.
Open up the air pumping efficiency, and the same power happens at MUCH lower boost levels.
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Urgh...
A compressor running continually at the pressure it needs to drive the tools is more efficient than one that pupst over the required pressure, shuts off, then restarts to pump up at some lower pressure. In air, storage storage storage is the key! The more storage capacity you have, the less horsepower you will need for impulse loads.
Air tools rating? Trash and marketing hype. See if you can find an Ingersoll Rand Air Tool Catalog---they are one of the manufacturers that shows the "real" consumption of an air tool when in actual 100% duty----general rule of thumb, 2 to 3X what the 'rated CFM' of most manufacturer's ratings say!
As I'm sure John C will say soon enough: Buy a used compressor, and industrial one that some local mom and pop compressor house took in on trade. Convert the motor to 220V single phase, and be set for life with a 5HP compresson made of good old American Cast iron sitting on a 120 gallon tank.
Use a regulator AT the tank, don't run the tools on tank pressure, you're wasting air.
What am I doing right now, besides shirking my paperwork duties at work? Supervising the Emergency Overhaul of an 8000HP Joy 4MSG12 Air Compressor for an Air Products 290Ton Per Day Air Separation Facility. Every day they are down it costs them $200,000 in lost production. Not a real big compressor, but big enough. The low speed rotating assembly weighs 686#, and spins at 12,800rpm. If you want specific questions answered, PM me, and I'll try to do my best to help you out. Air is my business...Air Solutions, more specifically. Damn, I sound like a salesman now... LOL
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I used the fuel tank expansion tank. Then I made a metal shield to separate it form the passenger compartment. You need to add more fittings (I TIG welded additional 3/8" NPT bungs). It works great, and is very stealth.
Evil, Evil, Evil! I bow to your stealthiness, oh great one! I now have a new favorite way to do it! Muahahahaa!
Great idea. My tank vents through a JDM 'dump tube' in the filler neck!
BTW, the relationship of the main pump to the boost pump is pretty much irrelevant as long as the surge tank is constructed properly.
The whole key to the Surge Tank Concept is to have the pickup to the main pump continually flooded with fuel under slight pressure to keep the main pump primed. The #75 Steve Millen IMSA car (Cunningham Racing) has two surge tanks almost the entire height of the car and 4" in diameter! ALWAYS had flooded inlet even if a big pocket of air was sucked by any of the booster pumps.
Fuel out the bottom, air and excess fuel out the top. The further between the two, the better. Taller than wider is the desired aspect of the tank profile.
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Mine at idle is about 152, and under boost can go as high as 190.
I have a 160 thermostat.
I noticed it stays fairly cool at idle, compared to when I start driving around when it goes up a bit, stabilizing under normal off-boost cruise around 160/165, but on a hot day (98-100F)it can be slightly higher.
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nice to see 'follow through' stories on people actually stepping up and buying parts they 'had an interest in' when a vendor was laying out capital to make production fixtures. it doesn't always happen. hopefully john's moulds will be quickly amortized, and his profit margin goes up to 'sustainable levels' so the parts remain available for years to come. thanks for the support, john.
even if my S130 needs to be heavy! LOL
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I guess by even thinking about Oxy-Acetylene, I expose myself as an automotive anachronisim...
Though in the 70's at competiton prep department, that's how they did it and it worked well for the day...
That's it, I'm going for a 'period correct' racer! My labor rate just tripled, I'm an artist, not just some hack!
LOL
FI Air intake on '73?
in Nissan L6 Forum
Posted
If you are intercooling a turbo car, then the tubing is FAR smaller than the OEM N/A ducting that goes through that hole. Turbo guys normally run a cone filter on the turbo directly, or fenagle the AFM to a place where the filter is out side the radiator.
Matter of fact, you are being taken in by an optical illusion! I know for a fact the stock Turbo AFM will take a full diameter tube through the opening you are talking about in the radiator core support of a 73...
So the N/A boot using a 'cold air tube' will fit through there easily as well. Just like posted above: unmodified.