Contemplating Fit conversion for DB1 in CMod

[na94]

I have been toying with the idea of doing a Fit conversion to my DB1 for some time now.

It seems like the Fit has more low-end torque, and is apparent when doing side-by-side drag launches at Pro Solo events. When doing hill climbs, I can also run the Pro restrictor (hills always require more power!)

There are a number of concerns that I have about the Fit motor however:

Lower redline - I will commonly run a bit over 7k to avoid a shift when possible. The Fit cuts off at a lower speed - I believe 6900 rpm. Could someone please confirm this?

I prefer to run 100LL in my car since it plays nice with the foam in the fuel cell and keeps over the winter - I am not a big fan of mogas. What are people running in their Fit motors and how do they preserve their cell foam?

A DB1 is a tight fit - where would I end up mounting the ECU? I do not have much room between my back and the fuel cell bulkhead.

I have seen a number of complaints about repeated sensor failures and quality issues - how reliable is this package? I really do enjoy the simplicity of the carburated engine.

If anyone has additional points to consider, I am all ears.

[EYERACE]

Seems to me you're going to go to a LOT of trouble and then will only put a few minutes of time on an engine per session..........the Fit idea was so that those Club Racers who rebuild Pinto top ends at ten hours of total run time and total engines after twenty hours of total run time would instead be able to run a Fit into the proverbial ground after maybe hundreds of hours instead and never need to touch the engine.

Looking for thousandths a run when others were looking for dozens and dozens of hours per seasons..........note the words seasons is plural.

[Jon C]

Redline is 6900.

We use regular pump gas, if the foam starts deteriorating (it hasn't yet) we'll just replace it and the fuel filter.

No computer/sensor issues for us so far.

Our car launches well at Pros mostly just because it has that super heavy stock Fit flywheel that you can store a ton of energy in. Terrible for the driveshafts, but worth a tenth or two.

[efoxfield]

The redline is 6750. The Honda is stronger than an average Ford but, not as strong as the top Ford's. Honda recommends 91/93 pump fuel.
After three years of no problems I had an ECU fail at Mid Ohio last weekend. $1,247.00 with shipping to Chicago.
For limited use I would buy a used Fit engine as the new ones don't make top power until reaching 3000 miles.
Ed

[ewcmr2]

60' results don't indicate Honda is better.
Mark was quickest,
http://scca.cdn.racersites.com/prod/...%2060FT_RT.pdf
Jon is outlier, Richard and I were even
http://scca.cdn.racersites.com/prod/...%2060FT_RT.pdf
I sent my cell to Eagle in Wisconsin to add access port. They said foam was fine for pump gas.
Winter/summer doesn't make much difference down here
6750rpm limit.
I installed ECU in place of removed fire bottle. UCU isn't very big, it can tuck in anywhere.
I havent had any sensor failures. Crank sensor failure is (was) common in Van Diemens. Exhaust runs very close to it, insulated silicone sleeve protection seems to keep it alive

[ewcmr2]

The big pluses are never charging a battery (or three)
Beng able to run cooling fan without worrying about running down battery.
Not having to prime carb with fuel after car hasn't been run between events.

Cold start is bad, if water temp is below 150* Honda barely wants to run, adding throttle usually kills it. Very annoying if you just want to roll car out of trailer and drive to tech.

[efoxfield]

I use a dime under the throttle stop for cold starts. I drilled a hole and installed a length of safety wire to the dime so it's not necessary to remove the ending cover for the morning start. It's true that adding throttle when cold will kill it.
Ed

[fitfan]

The redline is 6750. The Honda is stronger than an average Ford but, not as strong as the top Ford's. Honda recommends 91/93 pump fuel.
After three years of no problems I had an ECU fail at Mid Ohio last weekend. $1,247.00 with shipping to Chicago.
For limited use I would buy a used Fit engine as the new ones don't make top power until reaching 3000 miles.
Ed

are the top Fits stronger than the top fords though?

...that is a serious question BTW....

and do the fits make more power in lower RPM?

[efoxfield]

As far as power goes the Honda is strong between 5300 and 6600. It's not uncommon to short shift the Honda. A track like Road America probably favors a strong Ford motor. About the only thing that will damage the Honda is overheating it. In Atlanta this year I made several 3rd to 2nd while trying to get 4th gear and buzzed the engine to over 8ooo rpm with no damage.
Ed

[na94]

Thanks for the info guys. That low redline is the primary drawback IMO. Shifting costs time - and I have data to back it up.

I actually suspect that my motor has been a bit down on power for a couple of years given what my hill climb logs say. I will try to budget for a rebuild and upgrade over the winter.

Cheers!

[problemchild]

Thanks for the info guys. That low redline is the primary drawback IMO. Shifting costs time - and I have data to back it up.
!

In our FFs we change the gear ratios in the transmission.

[na94]

In our FFs we change the gear ratios in the transmission.

That only gets you so far when you have to do launch starts and you have comparable torque curves.

[Raceworks]

The big pluses are never charging a battery (or three)
Beng able to run cooling fan without worrying about running down battery.
Not having to prime carb with fuel after car hasn't been run between events.

Cold start is bad, if water temp is below 150* Honda barely wants to run, adding throttle usually kills it. Very annoying if you just want to roll car out of trailer and drive to tech.

I've found sticking something thin like a quarter or credit card in the idle stop for the throttle gets it to crank up & warm up in those situations.

[CM/FFdriver]

Thanks for the info guys. That low redline is the primary drawback IMO. Shifting costs time - and I have data to back it up.

I actually suspect that my motor has been a bit down on power for a couple of years given what my hill climb logs say. I will try to budget for a rebuild and upgrade over the winter.

Cheers!

My only thing about the Honda engine for solo racing is the cost, one thing is they don't make the conversion for every chassis, so the cost could be higher or get a newer chassis. My only thing is road racing people spend a lot of money to keep their cars at the top performance level and having to rebuild or replace a ford engine every 30 to 40 hours maybe less hours could be very expensive if you do a 3 day weekend at 1 hour each day (guessing at the time) and if you only do 10 events a year that could be $3500 to $6000 a year (again a guess) at maintaining the ford engine? please tell me different. I mean when you spend 14 to 20.000 for an install of the Honda engine that could be 3 to 4 years of Ford maintenance.

The Honda on the other hand for solo racing is or could be a little over the top when it come to maintenance or little to no maintenance great if you don't have the time to work on your FF/CM but I'm looking at it this way, just like the top paragraph and with the Honda's could cost 14 to 20.000 for an install and based what happen to the last Ford engine that lasted over 4 years of autocrossing and what he said was 60 hours of running with 1223 runs and has been guessed at 40 hours of idle time. Now to the point, you could buy 2 complete top of the line Ford engines? or 3 very expensive rebuilds which could last you 4 years in autocross trim if your luckly at 12 years in total and maybe more at the Honda's money.


I will be watching very close to this year solo national's to see how great the Honda is, if a Honda driver win's the class but the 2nd Honda driver finish's 3rd or lower then the jury still out in my book but if they finish 1 2 then I may pony up.

Ben

[Barry Ott]

Ben,
Being one of the Honda Solo guys, I think your assessment is spot on. You can run a kent forever in solo and do an occasional rebuild and you'll be just fine. From a financial and performance perspective, especially in solo, I don't think there's any reason to convert a car. We've had three years of Kent/fit competition at nats and it's clear the Honda doesn't guarantee a win. We all know solo is about handling and driving, and a couple horsepower either way won't get you the big trophy.
I really enjoyed doing the conversion on my car, I learned a lot and had a ton of fun, and I really like all the modern conveniences it provides, but I also threw away a bunch of money doing it. But, ehhh, we all throw away a bunch of money doing this for fun, I just chose to throw away a bunch of money building the car too.
Barry

[Roland V. Johnson]

With all the new parts in the Ford engine, we are running them 50 to 75 hours between rebuilds. One of my customers went over 100 hours. It was a bit down on power by then, but the Ivey invoice was under $4500 + shipping.

[CM/FFdriver]

With all the new parts in the Ford engine, we are running them 50 to 75 hours between rebuilds. One of my customers went over 100 hours. It was a bit down on power by then, but the Ivey invoice was under $4500 + shipping.

Well that hardens my cost points, meaning the 14 to 15.000 I would spend on a Honda engine could last me up to 15 years of autocrossing? and if it turns out the Honda engine is faster between now and then my Son need to get a job or by his own FF/Honda.

Ben