EFI for all cars ?

P

Protech Racing

Well-known member
Wandered Runoffs paddock. The LBC car's drivers are as old as the cars . Maybe the next gen of racers may be more interested in the carbed cars if allowed to swap to EFI.
The power would be very close and most testing has shown that carbs make more power due to charge cooling . But the EFI might run near optimal more often .
I found very little nay's. Mostly a solid yes.
It could add some years to these cars .
If someone would write a letter please . message me . Thanks,MM
 
This letter is already in the system and we've been discussing it for a couple of months. Seems to be mainly a yes from most drivers and owners.
An informal opinion on this thread could definitely help.
 
I'm 100% for this.

The power regulation is (or should be) managed by throttle body, intake manifold, cam lift, compression ratio. We don't need to add the complexity of tuneability to that mix.
We finally licked the Bosch CIS system in Chuck Mathis' GP/FP car, by finding a way to control it with a stand alone ECU - in a really odd setup that no one was ever going to figure out an implement again. It was logical to allow injected cars to all use electronic injection.

Looking at the struggles that some cars have with getting carbs to run as needed over the full operating range of a well developed engine/cam setup, EFI would give those racers a path to get it right much quicker and focus on car setup/driving like the rest of us.

Of course - the immediate challenge will be whether there are component sets available to enable "easy" integration of electronic injectors for each carb type.

AND it may require some monitoring of the affected cars to evaluate whether there is a change in BOP rather than a change in ease of prep.
 
Even though I have tons of money and experience tied up in (British) carbs, I'm interested.

Anything to close a performance gap.

I do want/need to hear more about how cars with multi-carb stock intake manifolds will or should be able to adapt for EFI.

Is everyone going to get a restrictor plate (or plates) in close proximity to the throttle body (or bodies)?
 
The engineering can be simple . At the simplest, any car could simply add injector bungs on the manifold . You would also need a wide band system , map sensor , , crank speed sensor , and coolant sensor if you want a good cold run up tp temp. Micros squirt or Mega squirt works well and can be simple to sort .
Replace the carb piston with a venturi or plug of some sort.

Or allow a weber style intake and readily available throttle bodies in place of the carbs.
 
I think it's long overdue but with this idea comes all the questions of how. Are we able to propose a generic set of rules that governs or allowances for all non-efi cars, or are we going to add details to each spec line of someone's proposed kit? As much as I think an open rule allowance for EFI would be nice and not really have any impact on BOP (from any BMC cars) the Adhoc will choke and sputter on that idea and I admit I maybe a little narrow sighted. I could see where I may be opposed to full prep engines getting open allowances. What limitations would be placed on the intake and throttle body(ies)? Fuel injection on its own will not help...intake design and throttle body size can help as part of the request. Without flow improvements I wouldn't personally convert. MGB appears to be the only one that can take off running right now.

Some cars can benefit more than others (8 port vs 5 port non-cross flow for example) ...mostly start up and maybe a little fill in area under the curve. Area under the curve is about all we've been able to improve on the midgets as the 1275 is done pumping more air with the components we are limited to. We will need allowances to improve the power cylinder and outright airflow, one of which was already declined this year for the 1275...except all the cool kids get more compression or at least 5 of the top 10 in this years qualifying. Can't wait for Road America :roll: :lol: Hoping for the 7th place HPNPC award.
 
While this sounds interesting, let me make a few important observations:
1. This is in direct conflict with Prod Racing rules. Cars made without F/I wont be the first step, then why not allow turbocharging or other means of boosting power and throttle response.
2. This offers little to small bore cars. Carbs make more power at WOT than F/I, while less through varying throttle positions. Allowing modern gearing options would enable more closely matching rev range to cam profiles.
3. This is an expensive proposition. Will require different cams, Dyno time etc.lots of long term development time and expense. The fast guys in our group spent the last year improving the already legal aerodynamics, and handling options and got noticeably faster. When are the F/I converters gonna find the time and $ to catch up to those improvements.
4. Why not stick to what we know. Weight reductions and choke allowances have been used successfully for decades. Once these have been exhausted, we should look elsewhere. For me, dropping 150 lbs is way more valuable than getting to play with F/I.
 
Jesse Prather":10dpo4pn said:
This letter is already in the system, and we've been discussing it for a couple of months. Seems to be mainly a yes from most drivers and owners.
An informal opinion on this thread could definitely help.
Click to expand...

Production based racing needs to remain strong, and addressing the use of aftermarket fuel injection needs to be undertaken. Many of the vehicles classified in Production are fuel injected. Many of the older production car models utilized fuel injection in the later years of their production. The use of EFI on a production classified vehicle should be permitted via the same kind of mechanism as alternate carburation in the PCS. The key to performance of those vehicles will still be the amount of airflow to the engine by whatever mechanism(s) determined appropriate.

The issues of competitiveness of specific cars is another situation. Doubt very much if the decision by Ms. Savage, et. al, to undertake an effort to race in the 2024 Runoffs at Road America depends on any desire to use EFI on the Spridget. Eric stated many of the general concerns in his posting. The elephant in the room is why can't the 1275 LPHP cars get some more air? There are off the shelf stock carburetors and a manifold that are/could be readily available and bolt on to the engine right now. This would be a positive step to encourage continued participation by many current participants, as well as draw more involvement at the Majors level and runoffs from those currently in the queue and sitting idly on the sidelines with cars gathering dust.

What about the X-1/9's and other cars that are known HP participants? Production needs participation not continued wrangling over exactly how much performance a change will permit. It's time to stop thinking status quo and make a change. If a change results in a little too much improvement, make another adjustment.

Does Production want to end up lucky to have 10-15 cars at a Runoffs venue. Certainly not. What does it take to ensure that 25-30 cars per class are in the field with good representation of all makes and models? Will the MX-2 make it's presence known at RA????? How about the Porsche? Why weren't there newer Mini's. Participation and attendance are the name of the game. All methods need to be utilized to make the runoffs SCCA's showcase event.

My 2+ cents worth of informal opinion.
Hopefully a replacement #64HP for Road America

Just wanted to add this: It was good talking with you, MO. JFTR, I would love to be just as old as the #98 LBC again. :D
 
What parts would you use to convert to EFI? Would those be optional parts for cars that came with EFI similar to the current alternate carbs?
 
Yes. All in favor.

Leave the DCOE carb on the manifold for the throttle flaps and spec'd choke restrictions. Weld a bung to the manifold for the fuel injector..

Absolutely.

.
 
This needs explanation of what would be allowed. I’m not against a general allowance for alternate if open to all. I would like to see how 2x 40mm ITB and a custom manifold compare to the rules on stock TB and stock manifold.

I’m all game for slapping ITB’s on my car just for the street cred. It won’t make me as fast as if I just get back on track.
 
Protech Racing":62r9uv6v said:
https://www.ebay.com/itm/325598748965?

This kinda thing . Drop on for a weber .
Click to expand...


Exactly Mike, just add whatever choke size required.
.
 
Wanna get into EFI discussions, direct comparisons, pros cons and how-to? I can help...lol

I have two 2L 914s, one a street car and one a race car. Both engines are recently built about the same: 40-over, a tad more compression (9:1? or 9.5:1?), a bit more cam with the race engine being a bit more aggressive. The race car (ex-ITA historics racer, L2 FP-compliant) has your basic dual-Dellorto DRLA 40s with 36mm venturis on Weber-like individual manifolds. The street car has the stock D-Jetronic induction that I converted to Microsquirt.

In Production, I'm allowed to run either configuration: "(2) Solex 40 PII-4, (2) weber 40 IDF, (2) Del’Orto 40mm, 38mm choke(s) max, or fuel injection."

If you want the details on the Microsquirt conversion, and you have some time (it's not for the "TL;DR" crowd), you can read about it here: https://tgadrivel.blogspot.com/2020/03/ ... art-1.html

A reason for the Microsquirt endeavor was to see how well an EFI conversion to the stock induction would work, in possible anticipation of converting the race car to EFI; every bit of that street car's EFI conversion is Production-compliant. The bottom line on it was the Microsquirt conversion is an improvement over the D-Jetronic because - even though it still has the same crappy TB, plenum, and runners - it gave me the ability to tune the system around Production-allowed modifications such as overbore, cams, and compression (D-Jetronic is not tunable). It Improved startup and driveability as well.

However, I cannot find any evidence that it improved power significantly; the dyno showed it about the same top-end power. After all, it's limited by the same 52mm(?) throttle body, crappy plenum, and old skool induction.

To take the concept one step further, I purchased a pair of 36mm TBs to convert the street car, using those same Weber manifolds, but have not gotten around to installing it (2023 has been a busy year). The conversion can probably be done in an afternoon, even with beer, and tuning is straightforward: https://thedubshop.com/dual-idf-throttl ... tors-vwss/

Toward that concept, in October 2022 I submitted letter #33317 to the CRB, requesting allowance of an EFI conversion of the Porsche 914 from the allowed 38mm Weber/Dellorto carbs on individual manifolds to throttle bodies of the same size and on the same allowed manifolds. After all, with the same bore size the engine should not flow any more air than the Dells.

It was denied, noting "It is not recommended to allow an alternate intake manifold or method of air/fuel delivery, as those are against the core philosophy of Limited Prep for non-rotary engines." No, I did not bother replying that the engine was already allowed that alternate manifold and/or method of air/delivery (that info was in the letter).* That kinda killed my immediate desire to pursue the idea further, but I may do those dual TBs on the street car just for the fun of it. It'll be more induction noise but those cars aren't exactly Cadillac-quiet to begin with...

But today, there's absolutely no doubt which way I'd go with the 914, should I decide to race it in FP: carbs all the way. The Dells flow more air, are quite tunable, and are rock-solid dependable. I have a tackle box full of jets/venturis/stacks for tuning. The race car fires up each and every time, idles smooth after only a minute of tickling the throttle, and I don't have to run an alternator (the only thing the battery does is start the car and power the brake lights and ignition coil, and it'll last all day on a historics weekend. And yes, I'm aware of the Race Enery Performance TDC, but "ignition coil don't care").

On top of the additional complexity of EFI, I'm now having an occasional no-start problem with the street car, showing no RPM during cranking; something with the CPS. Wiring problem? Connector? Or an adjustment (or failure) problem with the crank position sensor, which is buried behind the fan housing, which requires the engine to be removed to get to it...?

Carbs for me, man. As of right now, it would not even be a remote consideration to use Microsquirt on the stock induction in the race car. I may even convert the street car to Dells.

So, bottom line, the opportunity may be there to allow EFI conversions, but it will be a long SCCA row to hoe and may not produce the results you expect. - GA


*Then again, the Committee rejected my Letter #27838 request to put the 90hp 2L 914 in HP because, "2.0L is considered too much displacement for HP". Which was probably less than a year before they started moving 2L cars into HP...sigh...and then when I asked again? "The PAC would like to see these attempted [the 2L 914 campaigned against the Miatas and Acuras in FP - my words] to assist with these considerations." Sorry for the rant...
 
Well, I've asked to go the other way. I have been running a limited prep 1.8 8v in GTL for a few years now, dual 45's with 32mm chokes, and I've asked this to be allowed in HP with the same 90 lb weight penalty as the VW 1.6 and 1.7.

It has been rejected since no 1.8 motor came with carbs.

Oh well, I guess I'll just stay in GTL and run around at the rear.
 
IMHO, the EFI update should require whatever the Throttle body size that is currently listed .
Add injectors within 100MM of the head/intake joint . Keep the current carb for thr throttle body .
For the weber carbed cars, swap for the weber replacement ,pictured throttle bodies.
This can be BOPed with BTB dyno pulls. I offer up my dyno for free .


Tim, I would ask for 100# and go from there. I dont think that it will pull that weight , but worth asking .IMHO
Greg, maybe swapping to a VR trigger may help the start. I have found great results with the nissan VR trigger on the Microsquirt
 
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