Intersting observations on FI vs IDFs

[vandor]

Hello,

>So who's trying to spin this as though what you tried just can't be done?

Nobody has said that.

> or the guy that designed it trying to divert the blame to avoid being sued?

Do you think we'd be posting this if that was the case? Your 'reasoning' is not very logical.

> Vacuum canisters are used by many as a way to filter the wave pulses and give a steady reading.

It wasn't the quality of the reading that was the problem. We got it perfectly steady.

> Who chose the inferior EFI system?

I did. I have used it successfully in the past, but in this installation several of its shortcomings came to light. Yes, there is a chance a different FI system would have produced better results, and we have considered it, however we spoke to several people who tune FI engines for a living, and none could say that they successfully tuned an atmo street engine with IR TBs and hot cams. They had done plenty of turbo engines and full race engines, but not one like this. Furthermore, the FI systems shortcomings concerned driveability issues, not WOT power, so it's unlikely that a different system would have solved the lack of top end power.

>Why should anyone trust what you say if you can't even be standup

What do you think this post is? I can't be more standup than telling the truth. Funny you talk about standing up, when both Jeff and I put our names on our post, while you have not signed yours...

[ChrisSRT]

Jeff,
Thanks for sharing your experience with the rest of us. I've been following this on Guy's forum with great interest and hoping it would work out.
Chris

[aj81spider]

I think we should dial it back a little. We're all here because we love Fiats (why else would you buy a 30 or 40 year old car where you invest $X so that it will be worth $X/2 when you're done?). This forum is a great place for those who know less (for example me) to learn from the experiences of those who know more (for example Jeff and Csaba). They've spent way more time and money than I ever would and are sharing what they've done - and it's interesting reading.

Questions and sharing addition information is always good, but if we flame the people sharing their experiences then pretty soon we won't have them sharing those experiences. I would find that a major loss.

[racydave]

I found this informatiom very interesting and usefull. The TPS is at best a compromise, and a vacuum canister will not allow real load sensing in real time. If you follow a Fiat video on the Multi air system, you might realise how complicated, and how many man hours by the most intelligent engineers are involved to accomplish such a tall task! I for one am not smart enough, devoted enough, or have the monetary means to accomplish these feats! Jeff, I too admire your efforts, and appreciate the honesty, and hours of painfull work involved. Direct injection will be the ticket to the future, but it requires more than most individuals can accomplish by themselves. Personally, I will keep to my Webber 36 ADL and match up against any stock Bosh system. Keep on truckin Jeff, we appreciate the efforts! Now, back to my hole...

[baltobernie]

Jeff/Csaba,
I read the seven-page thread on Guy's site, and can see how a newbie would set you off like he did. Kudos on your perseverance, and please keep posting.

[NCArachnid]

Thank you both for the great write-up (I read both) and the "failed" experiment. I got 2 benefits from your work.

1) I learned that dual 44's are not a bad choice for power in a TC. I have no where near the money, time and motivation to "trial-and-err" an FI system for my car. Your work lets me know that properly tuned dual 44's are a decent choice and much more in the realm of possibility for the home mechanic (me).

2) You've shown again that the scientific method of meticulously testing, measuring and recording results is king. So many people sell (and buy) performance parts for their cars assuming it will make them better/ faster when actually it may make them worse! You've shown that we can't just assume since it is a higher technology system that it is better in all aspects of performance. I'm sorry it didn't work out as expected.

If I were to ever venture into the high-performance FI world, I would swap (close your ears purists) in a S2000 eng/trans with all the stock ecu and sensors (~200 RWHP @ ~9000RPM!!). But then it wouldn't be a FIAT.

Thanks for sharing and please keep the posts coming.

[manoa matt]

Stonebike, Since you are new, welcome to the forum. Please stop by the new members/introduction section and tell us a little about yourself and your Fiat. We'd love to hear about your Fiat, and any modifications you've done to it. Pictures are always greatly appreciated, FYI we love engine bay shots.

[baltobernie]

For the most "bang for the buck", the obvious choice is to buy a complete top end (or entire engine) from Mr. Croft and go on down the road. No wait ... the most bang would be to go out and buy a Miata or a Z3. But that's not why we're here, and that's not why we drive vintage Spiders. While most of us slog our way through amateur restorations via trial-and-error, I think it's great that somebody with deeper pockets and great commitment to the marque has gone out on the proverbial limb to see whats possible.

[maytag]

JEff & Csaba: KUDOS!

Don't quit sharing just 'cuz one new-guy with a less-than-proven knowledge-base flames ya right off the bat.

I for one have benefited greatly from the info you've shared, and the pain you've taken to share it.

THANK YOU!

And to Stonebike:
We always have room for a contrary opinion... I am full of them! But let's try to give proper credit and respect to the long-timers who have spent a lot of time and $$ helping the rest of us out. and remember that an argument is always more convincing if we have some context on who it comes from, and what experience backs it up.

[mdrburchette]

Wow Jeff and Csaba, what a hairy ride that experiment proved to be. Looks like I won't be looking beyond my IDFs for better performance. Thanks for sharing and I hope to see you guys at FFO Nashville this year with a beer in your hand instead of a wrench!

[kmead]

Csaba and Jeff:

Indeed, thank you for sharing. Merkle and I spoke at length about the trip to North Carolina at FLU last year, which sounded like a trip and a half.

We really appreciate having the opportunity to learn from what you have done. I work in product development and our watchword is to fail early and fail often, we can't afford to have a failure late in the process. There is much more to be learned by going through learning cycles, understand what is actually happening to solve the problem and create a working solution.

I am sorry one of our members doesn't have the social graces to communicate in a more appropriate manner.

By the way Csaba, I did get my 850 starter installed and will be sending you a synopsis of that process. As it happens, the seal on my water pump has failed so I will be pulling that and the radiator so the third nut will be a bit easier to access (as in fully tightening it). The starter works well and spins the engine up very quickly. It just doesn't sound right, more like a Japanese car spinning up...

All the best

Karl

[124ADDHE]

My real baby is my 87 V12 jag and I am real keen on the megasquirt route, it seems that the guys on the jaglovers forum have had excellent results with creating a tame, fuel efficient engine that also can be run much closer to optimum performance at all times with the engine management taking duty of the ignition also....I wonder why the fiat TC is such a bear.....

[maytag]

....I wonder why the fiat TC is such a bear.....

Maybe it's more about the inherent difficulties in making carburetion work with that many cylinders in your Jag? Maybe that is why the V12 responds favorably to FI as opposed to carbs.

It would be interesting to see some information on actual volumetric efficiency (and maybe it's in the other write-up. I admit to having not read it completely yet). But to say that carburetion works better than F.I. in this instance of course would never be proof that it works better in ALL situations... nor was it ever suggested that this was the case. But as great as comparisons are, some empirical data of the nature of "this is how effectively this motor makes power in this tune" would seem to be the only way of comparing to other motors in the way we're trying to do.

The temptation would be to go to a simple hp/liter ratio, but this would not take into account any of the many other variables inherent in the design.

Maybe this could be summed-up this way:

SHOW ME ANOTHER FIAT TC MAKING THIS MUCH POWER THROUGH THE ENTIRE BAND, AND WE CAN COMPARE THEN, AND SEE HOW THEY DID IT?

[timinator]

Hi maytag, I didn't know that on-ramps had speed limits. You are just supposed to slow down to the freeway speed limit before you get to the fast lane.
The main point I get from Jeff and Csaba's project is not the merits of either carbs or FI but how difficult it is to make a new setup work. It is always cheaper to go with tried and true setups. We always have an idea about what will work until physics and ability get in the way.
The question that I had with their setup was the use of four 40mm TBs. The OEM make 160hp and more with one 60mm TB. Could the fact that they were using twice the airflow of a 60mm TB have been the problem? Guess I'll have to wait for an answer. For those of us that like to get information from someone else's dime this has been a disappointment. Maybe though when you consider the 17 months and thousands of dollars spent on this project we shouldn't feel too disappointed. I think the only failure is in not trying. Can't wait to see what Jeff and Csaba are up to next.
Tim

[TX82FIAT]

Folks, this is a great thread and supplies a lot of value/information. A significant question to ask any Spider owner considering a conversion to any FI system is how hard and fast do you want to drive your car. Guy, Jeff, Csaba and many others are on point that there is some inherent limits to FI systems put on a Spider that max power out at the 6000 RPM range. I've spent the last six months working with some of the folks at Vicks as they customize a MegaSquirt system. I believe Plenum/TB design is where the limitations come to play. I do not have the math skills, time or money to attack that piece. The biggest problem I've had (that I think is now solved) are static charges buggering up components in a sensitive ECU. For me, the system in my car is exactly what I wanted. The car responds well and has loads of torque throughout the entire RPM range right up to the 5800-6100 RPM. If you want the car to pull up to 8000 RPM's with 150 HP to the ground then the current FI options will not get you there. However, my car is a fast street 40/80 CAMS, modified Exaust, 1800 head, HC pistons and other minor improvements that may be used for an occasional track day. For the price of the system put in at Vicks, I'm happy with the 138 HP to the ground (Dyno's). Smooth and hopefully time will prove reliable and maybe even fuel efficient. I have a standard transmission and a standard rear end for an 82'. If i put much more power in the car I'll certainly shred both. Jeff has done some awesome work on his car and I would not call it a failure. Jeff set a goal, he and Csaba aggressivley attacked this goal with what I consider all the right moves/parts. The result was not what they expected given thier knowledge of what a Fiat TC can do. For me, I have a lot less $ in my car and the FI system delivers in the range of my expections. Yes, there is a part of me that wants the car to pull strong up to 8000 RPM's. Then the middle age man in me comes out and says why, really, in a 30 year old car that you want to enjoy for another 30 years. a 2300 pound five speed with 138 HP (155-160 at fly wheel) smooth and strong pulling up to 6000 RPM's. I'll take it!!! Ray Prior