EFI VS Stage II

[AlphaDMC]

Which is the better upgrade to go with? I’ve heard great things about both.


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[Ron]

One way to look at it is, while EFI gives you a new reliable fuel delivery system, Stage II gives you a fresh engine with a little more performance.
Their prices say a lot... lol

[opethmike]

Two different tools for two entirely different goals. EFI gives you a simplified and more reliable, modern fuel system. Stage 2 gives you a tiny amount of horsepower for an enormous price tag.

[Michael]

Stage 2 gives you a tiny amount of horsepower for an enormous price tag.

And enormous bragging rights at DCS.

"Oh I see you went with the LS4....cute. I got the Stage II which preserves the soul of a DeLorean rather than selling out and doing the car equivalent of leaving your wife and kids for the stripper you met on a business trip in Phoenix."

Michael 1981 DeLorean Stage II ....I'm going to heaven when I die.

[dmcnc]

I'm dying!!!:rofl:


And enormous bragging rights at DCS.

"Oh I see you went with the LS4....cute. I got the Stage II which preserves the soul of a DeLorean rather than selling out and doing the car equivalent of leaving your wife and kids for the stripper you met on a business trip in Phoenix."

Michael 1981 DeLorean Stage II ....I'm going to heaven when I die.

[Riley88]

only true og k jet fans would understand

[David T]

If you don't consider the cost, the Stage II will give you a bit more performance, an EFI conversion will give you (if it is done well) a more modern engine management system. The ultimate would, of course, be both but now you are talking real money. If I were to consider it, I would go first for the Stage II as the foundation for further improvements such as EFI and then maybe turbos. A lot depends on your finances and where you want to end up when you are done.

[dodint]

"a tiny amount of horsepower"

A 67hp improvement on a 130hp motor is a 51.5% increase. That, on a car that really seems to need it.

Regardless, this is kind of like asking if one should get new tires or repair a bad glove box latch.

[Delorean Industries]

"a tiny amount of horsepower"

A 67hp improvement on a 130hp motor is a 51.5% increase. That, on a car that really seems to need it.

Regardless, this is kind of like asking if one should get new tires or repair a bad glove box latch.


Stage II dyno chart below. We tested all available products on the market to bring the actual numbers to the surface. Feel free to calculate your "drive train loss" to reach 197 BHP. :)

60917

[Michael]

Stage II dyno chart below. We tested all available products on the market to bring the actual numbers to the surface. Feel free to calculate your "drive train loss" to reach 197 BHP. :)

60917
Yeah but that's the 5 speed. If you were running the "mighty auto" box, those numbers would easily double!

[Josh]

Stage II dyno chart below. We tested all available products on the market to bring the actual numbers to the surface. Feel free to calculate your "drive train loss" to reach 197 BHP. :)

60917

Nice. The forbidden dyno chart. the 197hp stage 2 number is brainwashing at its finest

[Michael]

Nice. The forbidden dyno chart. the 197hp stage 2 number is brainwashing at its finest

A guy named SonnyV swears by stage II BHP numbers.

[dodint]

I dyno'd my car last year. It peaked at 114hp. 42% drivetrain loss is a ton, but I have zero faith in the transmission to begin with, it shifts like a milk truck so I can't imagine it's terribly efficient.

The same drivetrain loss on a stock motor would put me at 75hp.

It's also worth noting that I didn't pay to install the Stage II; it was there when I bought the car. I don't have a frame of reference other than my own car.

[opethmike]

"a tiny amount of horsepower"

A 67hp improvement on a 130hp motor is a 51.5% increase. That, on a car that really seems to need it.

Regardless, this is kind of like asking if one should get new tires or repair a bad glove box latch.

Yeah, except that 67 horsepower gain claim is complete BS. It's really more like 20, 25 horsepower.

[dodint]

That would sure boost the efficiency of the drive train.

Josh (DPI), what were the numbers for a stock 5-speed? That should provide control data for calculating drive train loss. From that it would be pretty easy to calculate what the Stage II motor output is if the drive train loss is relatively constant.

I don't assert the 197 number is correct. I don't even have a dog in the fight as I'm not looking to purchase anything. But from a mechanical engineering problem standpoint I'm curious.

[Delorean Industries]

89 is the average number from a five speed

[opethmike]

I dyno'd my car last year. It peaked at 114hp. 42% drivetrain loss is a ton, but I have zero faith in the transmission to begin with, it shifts like a milk truck so I can't imagine it's terribly efficient.

The same drivetrain loss on a stock motor would put me at 75hp.

It's also worth noting that I didn't pay to install the Stage II; it was there when I bought the car. I don't have a frame of reference other than my own car.

The real drivetrain loss on the UN1 is between 15-20%. It is not the 33% and higher number claimed (without proof) by much of the community. There are a whole bunch of other cars that use the UN1 and its variants and have been shown to not have anywhere near such a preposterous drivetrain loss. See - Lotus Esprit V8.

[opethmike]

A guy named SonnyV swears by stage II BHP numbers.

Epic old school reference.

[dodint]

Post 17 directly contradicts post 16. Nice.

That's assuming the 130hp number is accurate, anyway. That's a 31.5% loss.

Oh, so that puts the Stage 2 at 166hp if the 31.5% loss is accepted as true.

As always it lands right in the middle. Greater than '20 or 25' and well below '197.'

[Nicholas R]

Oh, so that puts the Stage 2 at 166hp if the 31.5% loss is accepted as true.


Which it is not.

[Delorean Industries]

Post 17 directly contradicts post 16. Nice.

That's assuming the 130hp number is accurate, anyway. That's a 31.5% loss.

Oh, so that puts the Stage 2 at 166hp if the 31.5% loss is accepted as true.

As always it lands right in the middle. Greater than '20 or 25' and well below '197.'

This is why we provide specs for what we build. Standard on anything forced induction and available per request on EFI and naturally aspirated installs.

[dodint]

Which it is not.

The constant moving of goal posts is what takes the life out of these discussions. I'm willing to say the '197' number is baseless. The 130 number? That's been the number for over 35 years. You'd have to bring some very convincing data for me to move off of it.

[Delorean Industries]

The best we produced on an engine dyno with a stock PRV using K jet was 127 with a converter (stock exhaust) 135 with a test pipe.


This was back during the development years.

60919

[Mark D]

A guy named SonnyV swears by stage II BHP numbers.


In before post is deleted :tongue2:

[dodint]

Thanks for the numbers, Josh.

I fully acknowledge that drive train loss might not be scalable in a linear way, either. It's fun playing with the numbers.

Bottom line is I have 114whp and my car can merge onto the interstate without an issue. Good enough for me.

[GCMW Deloreans]

This is why we provide specs for what we build. Standard on anything forced induction and available per request on EFI and naturally aspirated installs.

I was curious about the EFI set up, I almost got one.....almost.

[ssdelorean]

I dyno'd my car last year. It peaked at 114hp. 42% drivetrain loss is a ton, but I have zero faith in the transmission to begin with, it shifts like a milk truck so I can't imagine it's terribly efficient.

The same drivetrain loss on a stock motor would put me at 75hp.

It's also worth noting that I didn't pay to install the Stage II; it was there when I bought the car. I don't have a frame of reference other than my own car.

Wow, I would expect more from a car with a "Stage" upgrade attached to it. Not tuned correctly?


The constant moving of goal posts is what takes the life out of these discussions. I'm willing to say the '197' number is baseless. The 130 number? That's been the number for over 35 years. You'd have to bring some very convincing data for me to move off of it.


The best we produced on an engine dyno with a stock PRV using K jet was 127 with a converter (stock exhaust) 135 with a test pipe.


This was back during the development years.

60919

My stock daily driver when it was at 167k miles had 119hp at the wheels when dyno'd. One more HP than Patrick C's and he had the wider DMC Europe stainless exhaust on his car! Yeah, Patrick I'm still bragging bout that extra 1 HP from my stock pos :-)

[BladeBronson]

Big thanks to everyone who's actually taken the time to dyno. Is there enough information to fill in a chart similar to:



Config HP at crank HP at wheels

Stock ? ?
DMC Stage I (exhaust) - ?
DMC Stage II ? ?
DPI Spec I (exhaust) - ?
DPI Spec II ? ?

[Spittybug]

Isn't this akin to apples and oranges?
Stage II is an upgrade to enhance performance on top of the existing K-Jet system, right? It is cams, cylinders, exhaust.... mechanical improvements.
EFI is reliability of fuel delivery, flexibility of spark delivery and modernization of process control.

As Mr. Deming if one should attempt to improve a system before ensuring it is under control........................................... .

[Josh]

Isn't this akin to apples and oranges?
Stage II is an upgrade to enhance performance on top of the existing K-Jet system, right? It is cams, cylinders, exhaust.... mechanical improvements.
EFI is reliability of fuel delivery, flexibility of spark delivery and modernization of process control.

As Mr. Deming if one should attempt to improve a system before ensuring it is under control........................................... .

A bit late to the party there owen

[Josh]

Big thanks to everyone who's actually taken the time to dyno. Is there enough information to fill in a chart similar to:



Config HP at crank HP at wheels

Stock ? ?
DMC Stage I (exhaust) - ?
DMC Stage II ? ?
DPI Spec I (exhaust) - ?
DPI Spec II ? ?


I dont think you will have as definitive of an answer as you are looking for. Different dynos read high or low, and the calculation for crank horsepower is all over the map. It is mostly just a guess unless you actually dyno the engine. This is something only Josh at DPI has done. You would think DMC would have done this themselves, for the price they charge for stage 2 but instead they just made up a number and miraculously a large portion of people seem to believe it.

Adam K is keeping a somewhat similar tabulation with his "Fastest Delorean in the World", but that is out of the realm of PRVs.
http://www.fastestdeloreanintheworld.com/contenders.html

Perhaps we should start another thread posting delorean dyno sheets and videos (proof).

[opethmike]

PRVs are dumb anyway. Put a real motor in the car.

[Spittybug]

A bit late to the party there owen

Fashionably! But hey, I don't have a horse in this race anymore so why worry? :driving1:

And you may now refer to me as "Former Delorean owning Guru" so as not to offend those that profess to be Delorean Gurus.

[Michael]

As Mr. Deming if one should attempt to improve a system before ensuring it is under control........................................... .

Takes a real man with top driving prowess to reel in those monster horses under the DeLorean covers. My DeLorean was specially made without traction control...when I leave the red light and don't boil the tires....that's all skill baby.

[Spittybug]

Takes a real man with top driving prowess to reel in those monster horses under the DeLorean covers. My DeLorean was specially made without traction control...when I leave the red light and don't boil the tires....that's all skill baby.

:grouphugg:Your team building skills titillate me Michael!!!!!!

[Hill Valley PD]

Interesting. I used to lust after a Stage II, but Josh at DPI has turned the bar lights on and ruined it for me. What does a Stage I add besides sounds?

[Delorean Industries]

Interesting. I used to lust after a Stage II, but Josh at DPI has turned the bar lights on and ruined it for me. What does a Stage I add besides sounds?

60922

[S_J]

Isn't this akin to apples and oranges?
Stage II is an upgrade to enhance performance on top of the existing K-Jet system, right? It is cams, cylinders, exhaust.... mechanical improvements.
EFI is reliability of fuel delivery, flexibility of spark delivery and modernization of process control.

As Mr. Deming if one should attempt to improve a system before ensuring it is under control........................................... .

Excellent job on the Dr. Deming quote!!! Joe Juran would also tip his cap to you out of respect!

[CFI]

Interesting. I used to lust after a Stage II, but Josh at DPI has turned the bar lights on and ruined it for me. What does a Stage I add besides sounds?

Stage II, regardless of what it actually puts out in terms of horsepower, is a noticeable performance improvement (it sounds way better too).

Is it worth the price? Maybe. To me, the situation reminds me of the new Mustangs. It’s roughly $9,000 more to have the V8 instead of the turbo 4. A quick look at the performance numbers show that the big 8 isn’t all that much faster. But some people just want to be that tiny bit quicker, regardless of price. To those people, the Stage II makes sense.

[Hill Valley PD]

60922

Have you dynoed a Stage I? Just curious as to any power gains from that if any. Ideally, I'd like to get rid of the cat and run a more open exhaust. I suspect that'd wake the car up and be lot cheaper than a Stage II. I don't live in California or anything like that, so car is not subject to emissions testing due to age where I am.

[Michael]

"Wow...that thing sounds mean. Is it fast?"

Stage II owner: "You heard it didn't you?"

[CFI]

"Wow...that thing sounds mean. Is it fast?"

Stage II owner: "You heard it didn't you?"

Lol, yep!

Speaking of sound, I recently set my fuel mixture to book values and my Stage II is now much quieter. I’m not sure if that’s a good thing. Are they set rich on purpose?

[David T]

A stock PRV or a Stage II gets a very slight benefit in performance running on the rich side but it kills the catalytic converter (assuming you still have one).

[DMCVegas]

Stage II, regardless of what it actually puts out in terms of horsepower, is a noticeable performance improvement (it sounds way better too).

I'm gonna yield to the professional mechanics with the experience on this from the much higher number of vehicles they've encountered. But I can attest to the following:

I once heard a rumor that the PRV kits left the Douvrin factory without their throttle cables being properly adjusted. Lots of slack that prevent the engine from actually hitting WOT...so you never actually extract the full amount of power from the engine since you don't ever get the chance to open it up. Akin to never fully pressing the accelerator down. Again, I don't know how true this is, but I DID find that my own throttle was indeed improperly adjusted. After removing the slack from the rod that connections the spool to the throttle level, I sure as hell noticed a decent amount of additional power. And with adjusting the bracket for the Idle Speed Microswitch, I also had much better throttle response too.

Now there certainly wasn't any earth-shattering performance after, but there was a definite improvement to the performance of the engine.

Which brings me to the question of the Stage II upgrade. If this is a commonplace issue with most cars, as I have been told, could this be a significant factor with the improvement of the Stage II engines? Yes, there are also other parts that go into the upgrade, and they all contribute to the overall results. But a couple of little adjustments for myself made one helluva difference in my own car.

[opethmike]

That helluva difference is what, 5, 6 horsepower? lol

[dn010]

You guys have obviously forgotten about the last time this topic came up. It's all about the buttmeter!