SBC replacement - FI or Carb?
Discussion
So.....
We're literally poised to exchange on our other house (14 month sales cycle - buying and selling houses in the UK is a right royal PITA!) this week which will mean I can push the button on nice new turn key engine from our friends at American Speed. I'm looking at a reasonable spec 383 cu in (circa 535 bhp). So having chatted this through with Gale - an intelligent (self learning) FI carries a premium of about $2.5k over a carburetor engine.
Given that I already have the high pressure fuel pumps and return lines (from the old Kinsler system) this must be a no-brainer surely?
We're literally poised to exchange on our other house (14 month sales cycle - buying and selling houses in the UK is a right royal PITA!) this week which will mean I can push the button on nice new turn key engine from our friends at American Speed. I'm looking at a reasonable spec 383 cu in (circa 535 bhp). So having chatted this through with Gale - an intelligent (self learning) FI carries a premium of about $2.5k over a carburetor engine.
Given that I already have the high pressure fuel pumps and return lines (from the old Kinsler system) this must be a no-brainer surely?
Why SBC rather than LS?
Principally time and money. I'm garage less currently (whilst we go through planning - another PITA) so am having to give Charles Dunn the install work, which is something I would have done myself. So it has to be simple.
Cost 383 cu in SBC:
$12,595 with carb
$14,970 with FI
Principally time and money. I'm garage less currently (whilst we go through planning - another PITA) so am having to give Charles Dunn the install work, which is something I would have done myself. So it has to be simple.
Cost 383 cu in SBC:
$12,595 with carb
$14,970 with FI
Storer said:
Nigel
Are you planning to fit an SBC or an LS?
The LS is the no brainer especially if you just want 535Hp
LS3 with very light mods and good exhaust. Use your HP pump.
No leaks, idle sweetly in traffic, cheap to service and easy to maintain.
Paul
Understood and I did briefly consider it BUT the cost of the wiring loom, new exhaust, associated pumping etc ., etc would VERY quickly mount up. I think when I did a quick 'back of a fag packet' calculation an LS install would cost me minimum £5k more.Are you planning to fit an SBC or an LS?
The LS is the no brainer especially if you just want 535Hp
LS3 with very light mods and good exhaust. Use your HP pump.
No leaks, idle sweetly in traffic, cheap to service and easy to maintain.
Paul
deadscoob said:
Is that a landed cost?
If not, the FI is about £9k,plus shipping, import and vat?
That seems very close to an LS install. Appreciate what you say about simplicity of course.
So the premium for FI is about $2.3k neither of the costs are 'landed'. The FI engine will come to about £10k delivered as a turnkey solution. If not, the FI is about £9k,plus shipping, import and vat?
That seems very close to an LS install. Appreciate what you say about simplicity of course.
A 480hp LS3 is £5800
New headers £2000 approx
Ecu and loom £900
LS adaptor and clutch £1500?
Easy to say, and I know the above isn't an exhaustive list, but if it was me and I was faced with the choice above, I'd hold out until I could do the LS. If you're talking £10k vs 12, I just don't think it's worth going SBC nowadays, unless the other driver on top of simplicity is you'll activily want to tinker with it. An LS3 should be much nicer to live with, plus add more value to the car than a new SBC. Imo
New headers £2000 approx
Ecu and loom £900
LS adaptor and clutch £1500?
Easy to say, and I know the above isn't an exhaustive list, but if it was me and I was faced with the choice above, I'd hold out until I could do the LS. If you're talking £10k vs 12, I just don't think it's worth going SBC nowadays, unless the other driver on top of simplicity is you'll activily want to tinker with it. An LS3 should be much nicer to live with, plus add more value to the car than a new SBC. Imo
So the original question was FI or carb.
Fuel injection will/should make for a more tractable engine at all revs and generally a smoother drive.
Carb will normally give you better peak power but will be harder to tune and keep tuned for good road manners.
The Fi should give better gas mileage than the carb.
If you are track orientated then a carb should do the trick.
Personally I like FI, no flooding issues hard to bog down off the line etc.
As an aside I do agree with the LS conversion advice above, you won't regret it and ultimately will make it a more saleable car come that time, but it WILL cost you a premium to start with.
ETS There's also the emissions question to deal with £££.
Fuel injection will/should make for a more tractable engine at all revs and generally a smoother drive.
Carb will normally give you better peak power but will be harder to tune and keep tuned for good road manners.
The Fi should give better gas mileage than the carb.
If you are track orientated then a carb should do the trick.
Personally I like FI, no flooding issues hard to bog down off the line etc.
As an aside I do agree with the LS conversion advice above, you won't regret it and ultimately will make it a more saleable car come that time, but it WILL cost you a premium to start with.
ETS There's also the emissions question to deal with £££.
Edited by F.C. on Wednesday 11th November 08:39
No old school fetishes here - and given where we are with building new house/garage etc.. LS3 makes more and more sense BUT only if it can be managed cost effectively 
So the AS turnkey LS3 480BHP is circa $19,500 (everything inc., shipped and taxes paid) plus I'd then need an exhaust.....
Nabbott
So the AS turnkey LS3 480BHP is circa $19,500 (everything inc., shipped and taxes paid) plus I'd then need an exhaust.....
Nabbott
Edited by Nabbott on Wednesday 11th November 16:38
Nabbott said:
No old school fetishes here - and given where we are with building new house/garage etc.. LS3 makes more and more sense BUT only if it can be managed cost effectively
So the AS turnkey LS3 480BHP is circa $19,500 (everything inc., shipped and taxes paid) plus I'd then need an exhaust.....
Nabbott
In theory if you convert you may "get away" with the emissions thing as the car would have been originally registered with SBC, So come MOT it should flag up "visual smoke test only",So the AS turnkey LS3 480BHP is circa $19,500 (everything inc., shipped and taxes paid) plus I'd then need an exhaust.....
Nabbott
Edited by Nabbott on Wednesday 11th November 16:38
It is certainly the case with my car.
Dom. Having done this conversion I can say that you need to look VERY closely at self learn EFI systems with wild cams. The engine will not generate a lot a vacuum at idle and so the difference in vac between idle and WOT will not be much. Most self learn systems rely on a good vac at idle and will work badly with lairy race cams. My experience is with the Comp Cams/Fast system. Their entry level EZEFI system does not like big cams at all. The more expensive ones are able to be programmed to deal with it. My experience is also that they all say that they will work with 600hp and then run a mile when they don't! I had a 550hp AS motor and the EZEFI was way better than a carb as far as manners and cold start etc goes but ran very fat at idle.
V8Dom said:
which system are you fitting
what hp do you have
ive been thinking aabout it too if i dont go ls7,,, but have wild cam and 600 hp
My SBC is currently at 450hp, I have aspirations to boost. The carb I have is too large really (800 vac sec jetted right down) and doesn’t idle well (unsurprisingly) and generally stinks. Plus I fancy a project…what hp do you have
ive been thinking aabout it too if i dont go ls7,,, but have wild cam and 600 hp
I looked at the FAST system, at the EZ-EFI 2.0 MPFI stuff first and later at the XFI Sportsman. I even tried to buy at one point by couldn’t get a FAST to supply in the windows of opportunity I had at the time (I fly in and out of the US).
After being fixated on a self tuning system, more research led me to the Holley HP EFI MPFI kit. https://www.holley.com/products/fuel_systems/fuel_... I was attracted by the ability to support boost and CNP/DIS on the standard system (only needing a different MAP sensor). Its not a complete self tuning system like the EZ-EFI of (Holleys version, the Terminator or newer Sniper) but is looks like it will strike the right balance for me.
Read more than a few positive accounts around the Holley stuff, ready plenty of positive accounts about FAST, but also quite a few negative. I hung out on the Holley forums and founds someone who could supply the system but also (by watching the forum conversations) offered good afters sales help.
He did me a good prices on the Holley kit plus coils harnesses, crank trigger & cam Sync Distributor from EFI connection. Supplied the lot to the address I needed with no bother.
So now have a bench load FI & ignition to fit
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