loopy

iTrader: (1)

Ok,


The article I read from Vizard states that beyond 24" the primary length had very little effect on power. The secondary on the other hand does.


My thinking to this point is to keep the size of the collector right through to the termination box without merging at all thereby creating a long
secondary/collector to maintain as much of the performance as possible after the losses of the shorty headers.



The above was taken directly from his article posted here:


http://www.chevydiy.com/chevy-small-...haust-systems/



The million dollar question here is of course, what diameter and what length of secondary to achieve the best efficiency/power at open road RPM's which for me would be 2000-4000 rpm.

So. with that in mind I have been thinking. Now bear in mind that the following illustrations dont take into account actual distances and may well look totally different once the math is done.
My think re getting the secondaty lengths roughly the same even though the exhaust is running down the side of the car is simply to have the short side secondary run further into the
termination box than the long side. The added advantage of no need for a x pipe then either (maybe)


I have a rough illustration of what I am getting at below......

















You see where Im going with this?


What are your thoughts?

loopy

iTrader: (1)

I was tending toward the Dynomax as Vizard already suggests them anyways.


I also contacted Borla twice but have received no reply to either so obviously they don't want my money lol.


I don't suppose you have a recording of your exhaust sound do you?

skinny z

I'll be making an upgrade myself at some point and have been considering Dynomax as I'd seen some of there specs. I'll have to check them out when I'm ready to make a change. That said, I'd rather put cutouts on my y-pipe and run them opened at the track before I do anything else.

skinny z

Somehow your post slipped in there after I had replied.
Yes, I understand the importance of the secondary length. That's why I'm trending towards cut outs at the appropriate distance. That said, what I was getting at was without a termination box (or open headers), there's not much that can be done about the secondaries because, as I understand it, the secondary collector becomes as long as the exhaust pipe attached to it. See what I mean? The termination box changes that though.
Speaking of which, something that has to be considered, and one which one of our fellow board members experimented with (and something I didn't catch) was that the pressure wave tuning and the resulting increase in volumetric efficiency is largely dependent on the overlap the cam has. With a cam as small as the XR276HR or one which has a wide LSA, (which was the cam used in the experiment) the effects of the overlap are such that the tuning effect of the exhaust is not as pronounced.
Something to consider I think. It wouldn't be a total waste. The attention to getting the collector to an optimal length is far better than alternative where the length is such that there's a positive pressure applied to the exhaust valve and efficiency goes out the window.
I'll run the PipeMax program from my previous Vortec/276 build and post a screen shot of the results. I know you'll find it interesting.

Yes I do and I think (space notwithstanding) that it would be an excellent experiment.
IIRC, the optimum secondary for a build like yours (and my former one) was about 18". Then there's the 2nd, 3rd and 4th harmonics too. Those values escape me at the moment (but I think the 4th is approaching 8'! )

skinny z

Here's a screen shot of the PipeMax results. (Had to cut it up into 2 pieces but I think you can figure it out). I used a short header with mufflers. The results (as near as I can tell) demonstrate a header alone (primary and secondary/collector) as well as a tuned full exhaust length.

Night rider327

iTrader: (13)

Sorry, right now I do not. I have the one video on Youtube but that was with flowmasters. I had a couple of vids with the new dynomax setup but didn't upload them fast enough.... My desktop PC crashed and I lost everything.

I can make you a video of mine in a few days, maybe a week though.

loopy

iTrader: (1)

Thanks for that Kevin



Can I assume that the termination box would be viewed by pipemax as the total exhaust length?


Therefore, if I have this right, I could site the termination box at 38.5"
which in my installation would be a realistic length from start of collector to box.
So, 2 x 3" collectors at 38.5" long (meaning one would need to extend inside the termination box as per my illustration above), followed by a single 3" to muffler then tailpipes (trying to maintain the recommended total lengths just in case). This would optimise my setup for the 3700-6200 rpm range.




Just 1 question. What changes would optimise it for say 2500-4500RPM's?


I'm thinking cut-outs would be used any time racing was on the menu anyways.


Or maybe you could tell me, what price I will be likely to pay for the above setup if I am operating at 2300-4000RPM which would be my daily driving rev range. If theres no real efficiency cost at lower rpm maybe I'm better to stick with the sportier setup as per your screen shots.


this is really interesting stuff ....cheers!

loopy

iTrader: (1)

Thanks NR I would like to hear it.


No rush mate, still in the research stage anyways

loopy

iTrader: (1)

Ok, Been full on working for the past few months but finally moving on the car again.

The car is currently in the paint shop getting the chassis crack welded/painted

and the engine bay painted gloss black and rear end touched up where the paint had reacted and bubbled.

I ended up purchasing a dynomax #17554, 2 in, 2 out, 3" x-over muffler which flows 1400CFM apparently although I have seen 2200CFM bandied about too (not sure which number is correct). This will take up the least room and allow a side x side 3" pipe configuration from collector to tailpipe





I have stripped out all the engine bay wiring and old computer loom to simplify and hide the wiring as well

skinny z

Wow. That's quite the muffler. 1400 cfm?!
Be forewarned, dual 3" front to back is an ambitious project. I'm going to take the lazy way out and buy Hooker's Blackheart dual exhaust when the time comes.

https://www.holley.com/products/exha.../70501426-RHKR

Hey Geoff.
Just realized that I hadn't replied to your questions about the exhaust tuning. Maybe I'm not too late?

loopy

iTrader: (1)

No mate not too late. I think im gonna run out of money before getting anywhere near the exhaust lol.

Just to recap, my thoughts....

The 3" dual will be side by side all the way back.

The full exhaust should be tuned to suit daily driver duties with cutouts placed to take care of the (very) occasional track day.
That means tuning for efficiency in the 2-4500rpm range with full exhaust I guess. What are your thoughts?


It's certainly a lot easier when you can buy the complete system pre-made isn't it. I like the look of that hooker exhaust system . For me to get something like that freighted over here the delivery cost would double the price!.

Still, my sons an engineer so I'll get some mandrel bends and a bit of straight pipe and he can weld it all up for me. That way cost won't be too crazy.

I would love to explore that open box idea I had a few posts ago as well but not sure where to get that information.

loopy

iTrader: (1)

Well I got the car back from the painter today so as I have the next week off I'll start with wiring etc while I make a decision what to do with the auto.
I've been trying to get a price from probuilt for freight to New Zealand but its proving to be like pulling teeth. A long process. If you've got any suggestions re a good trans parts supplier I'm keen to hear them.
I've got some LS1 brake calipers on the way so I'll upgrade the brakes too. After all that maybe I'll finally get the auto back in.




At least itll all the same colour now
I just has the back end a d engine bay painted so it'll all one colour as the *** end was all primer when I got it

skinny z

Hey Loopy. I think I had replied to this exhaust question earlier but it went missing. Probably operator error...
More than one fellow has done it (the dual 3" over the axle) but I'll say that for our intents and purposes, dual 2.5" wouldn't kill any power potential for builds of our output.
As for the tuning side of things, trying to hit the right harmonic when you're considering the length of the exhaust right to the tail pipe is a challenge. And one of diminishing returns. The PipeMax program does provide those lengths as well as optimum collector, collector extensions with mufflers and points in between. As you're aware, getting a pair of mufflers, other than a straight pipe muffler (aka. Cherry Bomb) is very difficult if ground clearance is an issue. Lower your car and it's next to impossible.
My approach, and you touched on this, is to use cut-outs at the appropriate location along the collector or exhaust pipe for track days. The conventional exhaust, whether your idea of dual 3" or the more manageable 2.5", will take care of daily driver duties. I had a single 3" (still do) and although I genuinely suffer at the drag strip, where the car is at sustained higher RPMs, on the street it gets out of it's own way. The Vortec heads and supporting parts makes for more low RPM torque production and even though the exhaust may choke things a little at the top end, it'still a great truly street engine. Exhaust and all. Perhaps choke isn't the right word as twin 2.5 or 3" pipes and a pair of those monstrous mufflers you posted earlier certainly won't provide much restriction, the over all length notwithstanding. The harmonic may not be spot on but that can be determined and possibly corrected with a little analysis, modification and tuning.

Post up in the transmission forum for advice on what approach others have taken to modifying their 700's without taking them apart completely. I'm an old auto tech and I know better than to get too deep into the transmission guts. Swapping out a failed transmission is one of the most miserable jobs I can think of on our cars. The basic upgrades are simple enough though. Don't forget a decent torque converter. While you may not want to go the Yank, Vigilante or Edge route, guys here have good results with something as simple as the S-10 pickup converter.

loopy

iTrader: (1)

Re the exhaust.

Im wanting to run a dual pipe, single muffler system through under the passenger side. (The muffler is dual 3" and has a built in X pipe).

It will be 3" from collector to tail pipe.

As discussed we can put cut outs at the right location for top end power.

All that remains then is to site a termination box as per vizards article at the right location for peak efficiency at open road RPM, which I would guess to be in the 2200 to 4000 RPM range (this to aid best open road fuel economy). After the termination box it wont matter where the muffler is placed in the general scheme of things. I am assuming that once it sees the termination box it (the engine/exhaust) assumes open air from that point on correct?

That would be be do-able dont you think?

skinny z

Anything's doable.
Certainly, you can install the exhaust termination/resonator boxes (hereby forever referred to simply as "boxes") at a suitable location. Consider though that the boxes are essentially empty muffler cases and have to have a minimum volume equal to the displacement of the engine, per side. At 350+ cubic inches, that takes up a lot of real estate.
It would be easy enough to determine where, after the primaries end, to place the boxes. For a rough estimate, and I've calculated this on my last engine using PipeMax, the length of an open collector is about 18". Interestingly, this optimum length (which applies to the 1st harmonic reflected pressure wave), is the same for peak torque and peak HP. That'll give you both your best fuel economy, as torque is what you're after here as it minimizes the amount the throttle will have to be open for a given vehicle speed, and peak HP, as this is where the result of exhaust scavenging increases the volumetric efficiency of the engine and the resulting power.
Yes, you're correct in your thinking that after the boxes the engine doesn't much care what's downstream so long as it doesn't present a restriction. Remember 2.2 CFM of exhaust flow per HP before power starts to diminish due to back pressure.
Now there's something else to consider here and it's something that came up when another forum member did this experiment. His before and after results, from I can recollect (and I should look it up in my archives) weren't all that impressive. It got me to thinking as to why. The principle is sound enough. It's proven to be effective. So what gives?
Camshaft overlap.
His particular engine, with it's EFI and smallish cam with a wide lobe separation (California emissions requirement), didn't have enough overlap to get the scavenging to be really effective. Remember it's the negative pressure pulse produced by the open collector arriving at the exhaust valve at the moment of overlap (hence the term "tuned exhaust") and applying this suction on the intake port that initiates the induction cycle before the piston starts down the power on the intake stroke. Point is, the open header is especially useful on engines with more radical cams. Or at least cams with enough overlap to produce a noticeable result. The same applies to using boxes.
Where I'm going here, (and I don't recall your cam specs specifically), is that while yes, there'll definitely be a benefit to having boxes installed at the appropriate location, how much effort for what kind of return is the question you have to ask yourself.
Here's a link to an Engine Masters experiment comparing open headers with collector extensions to a couple of full length exhaust systems. The amount lost, although measurable on a 600+ HP engine, wasn't as much as I thought it might be.


Food for thought.
I'm open to debate.
And for what it's worth, while I doubt I'll go the box route myself, I most certainly will have a cut-out arrangement for my track days. Electric cut-outs would be really sweet. Just in case my track days happen to coincide with trying to merge onto the highway when that guy in the 7 series BMW wants my lane.

loopy

iTrader: (1)

So, if I have this correct, and from re-reading the article,

2 x 2-1/2" ( 2-1/2" to maintain exhaust gas velocity to aid scavenging) collectors into the box at the appropriate point.....

said box being the equivalent of 2 x engine capacity or 11.4L

Therefore the box needs to be 400x300x100mm minimum size. That gives me 12L.

I have read that rectangular boxes are prone to bad resonance so will have it made oval or round to minimise this effect.



PS. Just noticed this on Ebay



http://www.ebay.com/itm/3-Electric-E...mtr&rmvSB=true


I know this is largely overkill but it allows room for growth later should the need arise.

skinny z

Looking back over your PipeMax data (screenshot above) it looks like minimum collector diameter is 2.7" O.D. for best torque. Keep that in mind.
I had thought about putting both collectors into a single oval pipe when I was trying to figure out how best to pull this off in my own car.

http://www.spintechmufflers.com/imag...es%20chart.pdf

A 700 cubic inch cylinder would need to be about 44" of 3.25" x 6" oval tubing. It looks like there's enough room in the transmission tunnel to accommodate it. But just barely.
It would be easy enough to put the two collectors into the oval tubing. And just about anything you want out the back. Is there enough room along the passenger side as you've suggested? Not on my lowered chassis. I also have subframe connectors (Something I highly recommend by the way. I have Spohn's).
I'm just not sure how you could make it all fit.
Here's a look at the underside and how the collectors are up tight against the front subframe and have to snake around the transmission and crossmember.






Having a look at the picture from the rear, the trans tunnel does look promising. I've seen 2 x 2 1/2" exhaust stuffed in there. I do see that the collectors would have to be longer than the 18-19" spec. That's with a mid-length header. A short header would present a different situation altogether (I recall you having shorty headers is that right?)

Looking at the cutout pictures from E-Bay, it's difficult to tell but the butterfly looks to be very small with respect to the pipe itself. Can't say for sure. Good price for the stainless though.

loopy

iTrader: (1)

Wow when you put it that way it all l;ooks just a bit difficult to acheive with the lack of room underneath.
I assume that your 18-19" spec is the 1st harmonic?
What about the 2nd 3rd etc? are they equally effective?
I havent to this point been able to get such a good look underneath my car so thats a bit of an eye opener really.

I have Hedman shorties.

re the SFC's I was looking to go to the alston style


EDIT..... what about tuning for lower RPM (open road efficiency) doesnt that put the harmonics furthur back? Just a thought

skinny z

Check post #305 above. The PipeMax chart has a good explanation. I have the order of harmonics reversed. The 1st harmonic is the least desirable.

loopy

iTrader: (1)

I have spent a bit of time looking at those results but as per most technical things I find I have more questions than answers. Does the pipemax program come with a manual to help dummies understand the results? If it does it may be that I should buy it or some other book maybe (that doesnt get too technical)

Your pipemax results are based on a 3700 to 6200 rpm range?. Is this range input by you aor out put by the programme?

If I were to enter the operating range as 2200 to 5000 would that not require longer pipes to acheive the correct tuning( thereby giving more room so to speak) ? Or does the program tell you what the optimum RPM range would be?

skinny z

It's the program that calculates the operating range. If you change the values in the input field (at the top), the results will change.
That said, what is meant by "exhaust system operating range" is a bit of a mystery to me. I could use the same learning material you're after. That program goes pretty deep and it would take a lesson or two (maybe three) to really get a grasp on the principles and concepts. So don't feel that your a technological dummy.
I know from experience that the cam you've selected combined with your Vortec heads will not be producing it's best power at 6200. Peak HP is likely to be around 5500-5700 RPM with peak torque about 4000 RPM. That's the so-called "power band". That's a function of the engine configuration (relationship to bore/stroke/displacement), heads, cam, intake, exhaust, timing, etc. If you want to build more low RPM torque, then you'll have to build to that. I think you've done a pretty good job already.
Keep in mind, given what you've got, all that's left for you really is work the exhaust to try and promote the qualities you're after. At this point htere's only the header collector (I'm assuming you have everything else from carb to headers) and the rest of the exhaust system.
But given what you've assembled, and it's almost a copy of one of my engines (go figure eh?), you'll have plenty of torque below 4000. That's a virtue of the Vortecs. Add to that the DCR you've achieved and that engine will have plenty of pop off idle and will pull soundly on the highway without dropping a gear. I'm not saying it's a big block stump pulling monster, but I'm pretty sure you'll be happy.
The exhaust boxes notwithstanding, finish off your system with emphasis on flow.

loopy

iTrader: (1)

Awesome. I'll just carry on with figuring out how to shoehorn the exhaust in there then. The output from your engine specs gives the distance for the x-over and max tailpipe length. I'll try to design around that.

Thanks kevin

skinny z

Can you repost what you've assembled for an engine?
I can't do it now as I'm away working but when I get back to my office, I'd like to crank your numbers through a few programs.

loopy

iTrader: (1)

Engine L31 Vortec Crate engine. 4 bolt main truck replacement engine.

Standard vortec heads deshrouded and port radius smoothed only
My machinist measured chamber volume at 62cc.( I got 63 and 64cc when I tried)
Standard pistons Dish 12cc
Piston below Deck height 0.014" (this to allow for the .026" gasket while maintaining 0.040" piston to head).
0.026" Head gasket
Alexs valve springs
Scat prostock rods
Comp XR276HR Cam
1.6 Comp Pro magnum Rockers
Standard stroke
Davies Craig EWC electric waterpump and computer controller.

Induction

RPM Airgap manifold,
QF HR670vs Carby
CAI. Standard TPI intake with K&N carb hat
Mr Gasket electric fuel pump 95gph to QF bypass regulator.
Ignition MSD Streetfire HEI dist with Vac advance.

Exhaust

Hedman 1 5/8" shorties.
3" twin Exhaust
Dynomax 2x3" in 2x3" out 1400CFM advertised flow Muffler

And just FYI

I scored those Eibach sportline springs and Tokico 5 way adjustable shocks and struts.
Also got my hands on some LS1 calipers. They should look good inside my new 17" wheels with 255 and 275 Nitto NT555 tires

Need to get

LCA adjustable
LCARB's
Panhard bar adjustable
Torque arm. (It never stops does it)


Thought you might be interested in the guts of the muffler. It has a built in X over.












Cheers


Geoff

skinny z

That's what I recalled. Except for the 12 cc dished piston. That's the L98 short block then isn't it? Remarkably similar to my 2nd Vortec build although I had a flat top piston with 5cc valve reliefs.

I like your electric fuel pump and bypass regulator. I've finally seen the light after several seasons struggling with my mechanical set-up. I've rebuilt my Holley Blue electric pump and have their bypass regulator mounted on the frame rail near where the mechanical pump used to be. I'm counting on it making a difference in both performance (by way of keeping the fuel circulating rather than heat soaking when I'm waiting in the lanes at the track) and durability. I've had a fuel pump push rod mill it's way into the cam lobe filling one of my engines with metal. Not very nice.

I see 1 7/8" headers? I hope you mean 1 5/8".

I wouldn't knock yourself out with the adjustable LCAs. That serves no purpose other than to locate the wheel in the wheelhouse. A stout aftermarket non-adjustable piece is all that's needed there. It'll save you a few bucks. When I first got into this, I simply had my OEM arms boxed with metal plate and installed poly bushings.

Do you have the info on the LS1 brake upgrade? I did the installation myself with the abutement brackets purchased from Flynbye Performance, spindles cut and drilled by myself and rotors turned down into hats by a friend with a lathe. Great upgrade.

I like the Nittos.

It's looking like you'll have a pretty decent ride whrn it's all assembled.

Question: What would a fully modified version of our cars sell for in your country? Lets say I was to transport mine there and leave it behind after touring the islands for a few weeks...

loopy

iTrader: (1)

LoL yeah I meant 1 5/8" headers...just the standard shorties. They are away being ceramic coated at the moment.

The engine was a crate motor L31 4 bolt main truck replacement motor.

(I have edited the above post)

I got the info for the brake upgrade from bigbrakeupgrade.com

My son is an engineer so he can get the brackets plasma cut and discs machined down.

What was the spindle drilling you spoke of? I dont remember reading about that.


As far as values go. At the very top end 3ed gens are listed around $20000 in NZ.

Check out

http://www.trademe.co.nz/Browse/Cate...ch_suggested=0

As you can see most are in the Mid-teens.

skinny z

Handy having a son that's capable.
As for the spindles, in order to install the brackets, a chunk of the spindle has to be cut off. Then the brackets need to be attached. Not certain of the specifics at the moment but here's a link to a website where I gathered my information from.

http://lukeskaff.com/projects/car/th...brake-upgrade/

More specifically....

http://lukeskaff.com/projects/car/th...-modification/

20k for an upper end sale price eh? I imagine shipping would eat up about a half of that!

loopy

iTrader: (1)

Check out Kiwi Shipping. They freight cars into NZ from California.

Last time I asked them it was about $2500 NZD to get it here, then whatever customs and MAF costs are.

Not sure how the law applies to visitors to the country but for kiwis importing vehgicles there are a few hidden costs plus Taxes @ 15%

skinny z

Wow. That's quite the muffler. You'll likely have it installed long before I decide to pull the trigger on a new exhaust. You'll have to post some sound clips. I'll be interested to hear it.

loopy

iTrader: (1)

Yeah mate I will. Should be reasonably loud ( I hope so) but without that awful cackle some exhausts get.

skinny z

Any news?

loopy

iTrader: (1)

Nah the wheels of dollars earned move slowly when you drive tractors mate. I am currently saving to rebuild my 700r4 which is stupidly expensive in NZ.

Rest assured though Kevin, you will be the first to know when I do get there

skinny z

I'll be waiting.
Maybe I'll have my lump reassembled before you!

loopy

iTrader: (1)

i am shameful I know, but I think if I wait a bit longer for an auto, its gonna be a much more satisfying experience

skinny z

Hey Geoff.
I hope this finds that you and yours survived the natural disaster. I believe I saw that Blenheim was the epicentre of the earthquake.

loopy

iTrader: (1)

Hey Kevin

The epicentre was south of blenheim. We are in Seddon and my house is trashed. Were not allowed back in, due to issues with the foundations. Luckily we have a camper to live in.

On a brighter note, I now have a Hughes street strip 700r4 for the camaro so should be moving on that once I get my life sorted out

skinny z

Wow! Well I hope it works out for the better after it's all said and done.
It's good to see you have have a positive spin on the situation.

As for your Camaro. A new transmission eh? This thread may interest you.

https://www.thirdgen.org/forums/tran...goes-bang.html

loopy

iTrader: (1)

Hey Kevin
good new, bad news........

Then company I work for has decided not to repair my house. so it is being knocked down and im soon to be homeless.

The good news, I have found a mechanic who has agreed to install engine/auto and get my Camaro mobile after New Years, early January some time.

Progress at last!

skinny z

That's a tough one on the home front. What does that mean for you? Hopefully it's not living in a van down by the river (an American colloquialism demonstrating homelessness...!)
As for the Camaro, well I suppose that's something to look forward to. I hope your mechanic is knowledgeable and trustworthy.
On a similar note, when I moved from my old homestead after almost 30 years, I found myself homeless (or nearly so) as well. Not being able to slide right into a house of my own, I rented a room from one of my kids. Quite a culture shock actually however, having the hot rod parked in the driveway provided some solace as I was able to escape to it and enjoy myself even it was just to drive around the countryside and burn through a few dozen litres of fuel.
I trust things will work out for you. I also expect you to keep the rest of us posted on how things are going. Home and car.

skinny z

How are things Geoff?

loopy

iTrader: (1)

Hi Kevinon the car front, little progress. The car is at the mechanics atm. the engine is being moved down there this coming week.

im currently busy shifting to our new house so no time to deal with the install.

nothing good happens quickly or so it seems

loopy

iTrader: (1)

Well believe it or not a little progress!





Just mocking up the pulley set







Engine in!



Starting to install everything.

WOOT!! finally after damn near 2 years I can see the end in sight

skinny z

!!! Good to see you back into it Geoff!!!
Can we look forward to updates that aren't 18 months apart (earthquakes notwithstanding)?

loopy

iTrader: (1)

Hi Kevin!

Sorry but its taken this long to get my mechanic on to it. I had to wait for him to have a foot operation and then rebuild a mustang (ugh) and Holden engine first.

Yesterday was the first chance ive had at it in months as its been languishing outside his workshop for 5 months.

Anyways, we are away now.

I've decided to get new alternator and power steering pump as they looked so awful beside the CVF racing pulley set so that's my next roadblock to get past.

skinny z

No worries about a timetable here and I'm no stranger to long periods of inactivity myself. Over the last couple of years I've gone from heads off and to the machine shop Dec 2015 to actually driving again in the fall of 2016. The ported heads and new cam I'm guessing were too much and the torque converter blew up two weeks later. That was another 6 months until the new transmission, torque converter and because of a mistake by my trans builder, a new crossmember and exhaust (long story) were in place. That was well into this past (northern hemisphere) summer. Now it looks like the high mileage I've heaped on the shortblock is coming back to bite me and I'm looking at a bottom end refresh. I'm loathe to just move sideways (again) and will probably be moving up to 385 cubes but that's only in the early planning stages.
So much for my updates.
Now I'll be looking forward to yours. That's a nice looking engine. Good luck with it and the rest of the project.
Post up even for the modest stuff. People want to know.

loopy

iTrader: (1)

Well I was looking at various EFI systems and saw this

https://www.summitracing.com/int/par...0500/overview/

I know it’s not port nor direct injected nor does it tie into ignition, but what are your thoughts of this as a basic carby replacement?

I’m thinking it removes a lot of the chore of carby fine tuning which is largely witchcraft and that alone interests me

loopy

iTrader: (1)

Scat do some rotating assemblies that I was looking at earlier. Not badly priced either

skinny z

What do you have for a fuel system now? Tank, pump, fuel lines, regulator, wiring, relays, etc?

I've been looking...

loopy

iTrader: (1)

Funny you should ask that.......


I was going to use an external fuel pump to bypass regulator using the original metal fuel lines t9 get from tank to reg.
I have since been thinking about going to an in tank tpi pump .

All wiring etc will need to be installed no matter which way I go

Just thinking out loud really

skinny z

Not if you go carbureted. Unless of course you have no provision for a mechanical fuel pump.
Seriously though, I can appreciate the FI route. If I were to do it over again, considering what I've gone through with carbs, I'd probably go the injected route too. Not sure if I'd go with the Summit brand though. That would be one area I figure you'd really get what you pay for. That said, I haven't investigated the options other than what my racing friends are using.
But, in defense of carburetors: The tuning isn't all that difficult. I am familiar with Holley and Holley 4150 style carbs. Demon (which I have now), QFT (which I'll be getting next) etc, all have the same basic operating functions. With a wide band O2 sensor, a vacuum gauge and a tach, the tune is a step by step process. Now while some here will say that a few adjustments here and there and you're golden isn't exactly the truth. While the initial setup can be fairly quick, the real tune takes miles of driving under varying conditions. And the results can equal that of fuel injection.
Now all of that said, it doesn't tune itself. One thing I do know about the self learning FI is that it too is limited in what it can accomplish. From what I understand, the self learning feature combined with one that is programmable via a laptop, is the way to go.
It may be worth thinking out loud via another thread. There are a lot folks here with experience and opinions.