craig brian johnson

I've gone thru the evolution of my C4 track car. I've suffered thru a season of sorting just to get the car finally drivable, the expensive of ill matching parts by "finding the weakest link, I've lost entire seasons "going back to the drawing board" because of SCCA rule changes.

Now that I'm a little older I realize that my goals have changed. I think I'd like:

1) a well sorted C4 that stops as good as it accelerates.
2) runs at least top 4-5 in SCCA class ITE.
3) engine runs on pump 92 octane.
4) reasonably comfortable.
5) reasonably reliable, with no more than 1 engine re-fresh per season.

I have a shop full of C4 parts, stock and aftermarket. I have racing engine, drivetrain, suspension, brake components and spares.

I don't think that the race engine is an appropriate option in it's current form. (400ci, Brodix -10 heads, mechanical roller) I'm not sure if my current transmissions can be used in a less "radical" build (Jerico's). I do not have any stock displacement engine components or OEM transmissions.

I'm looking to buy a new C4 roller and spend the winter on a re-do. I'd like to use use as many of parts that I currently have; the problem is picking the right parts to be consistent with my "wants list".

ITE rules are basically: Stock body/frame running on DOT tires.

Is there any wisdom out there to keep me from overshooting my mark? (see mistakes made thread)

Thanks for your input.

eogel

PM sent

72tccracer

I have the completed car to what you are looking for. Fast reliable.
email me at cmac75@att.net
Chuck MacTrinder

eogel

I have the completed car to what you are looking for. Fast reliable.
email me at cmac75@att.net
Chuck MacTrinder


I have raced against Chuck in this car. It is what he says. I finally beat his best lap time at Road Atlanta this year, but he was not there to defend it, so it probably doesn't count! A good car and a fast car. If you buy it, keep it west of the Mississippi River.
Ed

craig brian johnson

Thanks friends:

I know that it's likely more practical to buy a well sorted, well maintainted race car, but my "thing" is more about the mechanical part than the driving. There was a time when I actually thought that I had built a pretty good car; lap records in ITE, it'd thrill the hell out of me just to rip thru the gears... but now that I'm not so serious, I need to tone it down some.

Here's what I plan on doing; you please chime in with your ideas.

I plan on finding a new donor car and using most of it's body structure.

-I'll keep the OEM windshield and heater/defroster intact.
-I'll keep it's OEM drivers door and latch closure assy. I'll use my lightened hood, pinned pass door and rear plexi-glass.
-I'll use my current control arm setup ('84 upper/late model upright and lower)
-I'll use my current Goldstrand rear links and toe rods.
-I'll do away with my bilstein/coilover set up and go back to a leaf spring (hd front/'84 rear/ Bilstein Sears-Point vavling).

-Rather than de-tune my race motor... I'm going to replace the Brodix heads/tit valves/mechanical roller cam and valvetrain entirely with some type of street performance head and street friendly valvetrain. Any Idea's on a 400hp/400t street hyd roller head/valvetrain package?

-The bottom end is a 400ci/400 mains World Products 4-bolt, 9.000 deck, lunati forged/flattops. It should be overkill.

-I'd like to keep the dry-sump. Has anyone pulled this off successfully with the engine in it's stock location?

-I'd like to keep the button clutch.

-I'd like to keep the Jerico and re-gear with a more "normal" gear spacing.

-I want to stay on DOT's... so I'll keep the Grandsport rims and run on 275x17 front and 315x17 rear.

-I'd like to try my Willwood GNIII fronts/ J-55 rears with the DRM re- worked Tahoe master cyld and OEM booster. With a street cam, will I likely build enough vaccum to run the booster?

Thanks for chiming in.

Slalom4me

My vote is that with a 'street' cam (110 Plus on the LSA) and a good metal
booster that there will not be a problem with sufficient vacuum. I have
chosen to use a Hydroboost - this is another route available to you but I
recommend sticking with an OEM equivalent vacuum booster if at all possible
if you are going to the trouble of rebodying for the sake of reverting to
the OEM pedal box. If desired, I can look back to pull up information
and links about the aftermarket metal canister boosters that CF members
found to be superior replacements to the OEM plastic style that suffer
in the presence of header heat.

AFR's new Eliminator heads appear to be very strong and reportedly deal
with past problems regarding drainback. I elected to go with small TrickFlow
heads for a much milder application and am very happy with the bang/buck,
others with more serious needs have reported favorably about TF's higher
capacity heads. When shopping, be sure to compare flow rates between heads
with similar chamber sizes: all other things equal, a 72cc chamber will
flow better than a 64cc.

Regarding retention of the dry sump, wndopdlr shared his journey toward
a reliable system in threads here '06/'07. His setup did not require the
K-member modifications that I believe I recall you mention making on your
current car.

I am curious about why you are electing to step back from coil-overs?
There have been a number of debates and IIRC, the nay-sayers are concerned
about durability of the mounting points while those in favour say the
mounts stand up and the spring rate adjustability is a big benefit for
lightened cars and varying tracks.

Is part of the object in rebodying to step down a few class levels
while extending the life of the accumulated C4 platform knowledge and
hardware inventory? If competition is no longer in the cards, isn't
it feasible to give the current car a reprieve with further effort into
domesticating its engine, adding the defroster and putting more
development into the brakes? Not expecting justifications, only offering
food for thought.

.

craig brian johnson

Slalom4:

I'll need to find out more about the brake booster options that you've mentioned.

I think that you are right on base with the cam and head recommendations. A good torque package with a 10:1 or so CR... limit the rpm's to less that 7k with a softly sprung street hydrollic roller. Run pump gas. Racing is now cheap(er) and reliable again!

I will be looking into the threads of wndoplr, and I'm excited to find that someone has had some success in putting together a dry sump package that doesn't involve chopping up the car.

I've never had any trouble with the strength of the shock mount points, even with very tough abuse (using the birms, etc.) Although, I have experienced the negative consequence of having "too many adjustments", or..."just enough rope to hang yourself"... I want to do away with the coilovers so that I can concentrate on the pleasure of driving... and not on the work of tweaking with the spring rates, corner weights and shock package. For all that they are not, the leaf springs are simple and don't take much tweaking... you merely learn to drive around thier quirkiness.

My object is more along the lines of racing a car again, instead of racing a "race car"... I have found that there is a big difference between the two.

Thank you again for your comments/recommendations... it looks like I'll be getting back to the garage again this winter for some more fun!

Slalom4me

Several members have written about good results with a unit sold by
HotRodsUSA.
You could try contacting the following members for their opinions about
the HotRodsUSA item.

John89
88 Coupe
Carl Johansson
vinnies87

My Hydroboost came from HydraTech Braking Systems. As mentioned
previously, I recommend staying with a conventional booster if possible
for reasons of simplicity, cost and so on.

.