Alfa Romeo Forums banner

1 - 20 of 49 Posts

·
Registered
Joined
·
157 Posts
Discussion Starter #1
Mirko and I have been building these two cars together to run in Sport Touring (ST) Class here in the Northwest with ICSCC. A few pics of the car, more to follow.
 

Attachments

·
Registered
Joined
·
4,090 Posts
Nice Chris - post some more pictures!
Jes
 

·
Registered
Joined
·
615 Posts
suspension, engine, tranny, wheel size, etc?
Thanks
 

·
Registered
Joined
·
173 Posts
Nice!

Hey Chris!

Nice work. I'm following Mirko's build too. Can you provide a link to the rules that you are building the cars too? I am familiar with the SCCA GCR and class rules, but not the ICSCC ST rules. It would be great to understand the framework that these two cars fit into.

What is the first event you expect to compete in?

Thanks,

Chris
 

·
Registered
Joined
·
4,520 Posts
Chris -

Nice looking roll cage. How is that front a-pillar base mounting point classified? Is that a single point as seen by mounting plate or 2 points? Looks awesome. Like the Stack gauges too.

Good work!
 

·
Registered
Joined
·
623 Posts
I hope that Chris doesn't mind my answering some of you questions... I'm he'll have more to add.

ICSCC regulations:
International Conference of Sports Car Clubs

ST class site:
http://www.race-st.com/

We're both going out with pretty much stock motors, Chris with a 2.5 and me with a 3.0. Both motors have S cams, both will be running 4.10/lsd trannies, 8x15 Team Dynamics rims with Toyo RA1 (me) and probably Nitto for Chris. Both are running full RSR suspensions and both with GiroDisc brakes front and rear. As both cars sit right now they are just under 2100lbs without driver (final weight to come in a week or two).

We spent a great deal of time studying the rules both for ICSCC and the ST class in terms of the cage build, and we took advantage of every possible angel. The plate represents a single mounting point, so that A-pillar picture shows two pipes connecting to one plate which counts for one primary mounting point (six total are allowed).

Mirko
 

·
Registered
Joined
·
173 Posts
Under 2100 lbs!

Holy cr*p! That is awesome. I can't wait to see how you did that! These cars will be fun. I will read through the rules...

~Chris
 

·
Registered
Joined
·
173 Posts
Roll cage rules

" Roll cage shall meet Improved Touring standards described
in the SCCA GCR (GCR: 9.4) except for the following: Any
number of additional mounting points and/or tubes may be
used. Two (2) forward cage braces per side (total of four)
may pass through the firewall and connect at no more than
two points in the engine compartment (i.e. strut tower or
frame). "

These rules allow a very extensive cage. No worries about number of attachment points, etc..

I was also surprised to see a 2400 minimum weight with driver. This means you need 240 hp to be competitive. This will be tough with a 2.5 V6. Are they talking whp or it there a standard correction factor they will use to estimate chp (whp + 10 / .88 = chp for example)?

The rules also allow 10" wide wheels. :eek: Dot race tires will limit what is practical on a Milano, even with fender flares.

It seems the ideal target for this class is minimum weight, huge tires, and a 3.5 ltr 12v V6 will a torque peak just under 240 lf/lbs. You could then set your rev limiter to prevent hp above 240. I looks like you guys have the weight beat and will need to run 100-150 lbs of ballast to hit your minimum with driver aboard.

This seems like a very fun class with a lot of creative freedom for a car builder. I can't wait to see how you guys do on the track.

~Chris
 

·
Registered
Joined
·
157 Posts
Discussion Starter #9
Details...

Basic spec for the car so far...

2.5 litre with S cams, headers & stainless exhaust side exit
Platinum transaxle
Girodisc G2 brakes
Full RSR suspension
Team Dynamics 15x7 wheels
225/45-15 Nitto NT01 and Toyo RA1 tires (slicks later)
Evo Kit
Carbon fibre hood & trunk
Lexan side and rear windows
OMP seat, belts
Fire system
Stack gauges

Later comes the power. Toying with turbos on the 2.5 to achieve 240 whp. Building another transaxle, close ratio. Will be lightening the rotational mass with lightened flywheels, and gotta do something with the driveline.

More pics soon.
More
 

·
Registered
Joined
·
2,984 Posts
I seen something like that before with the power limit with vetts.
the trick was to use a big block and have the cams/ECU set to give a decreasing ramp so the HP is flat.
So the BHP limit is from idle to redline. drives like a electric motor.
No point in shifting as long as you are in the range of the motor can run.
the car will accelerate at the same rate no mater what gear you are in. as the power at the wheels is flat to the spec limit. ( if set up right)

a super big supercharger will work too. way to big displacement and gear is backwards. so it turns slower than the crank. that way the PSI goes down as the RPM goes up. again going for a flat BHP line. The tourq should ramp down peaking at low RPM and dropping as the RPM goes up.
This kind of setup can be hard on the gear boxes as you want way more tourq down low.


The vetts move from a small block 350 5.7L to a big block 454 7.45L(or bigger)
detune to get the down ramp in tourq and have a flat BHP.

This is one of the rules that was to save money but works the other way around

Where you need stupid big displacement and very strong gear boxes.
A big diesel would be very good with that type of rules too I bet.
 

·
Registered
Joined
·
1,782 Posts
a super big supercharger will work too. way to big displacement and gear is backwards. so it turns slower than the crank. that way the PSI goes down as the RPM goes up. again going for a flat BHP line. The tourq should ramp down peaking at low RPM and dropping as the RPM goes up.
Ummm, perhaps you should be buying Greg's book on supercharging.
You can't have a supercharger 'geared backwards' and expect the boost pressure to taper off at higher engine speeds. You could try a smaller supercharger than what the engine should have, but to put a big supercharger on an engine and spin it slowly is a very poor choice and 1 that will result in a more progressive increase in boost with an increase in engine speed. It would act more like a centrifugal supercharger than a traditional positive displacement supercharger installation. Greg explained it really well in his book.
 

·
Registered
Joined
·
173 Posts
Forced Induction

Duk is correct on this one. You could either use a small positive displacement supercharger that is outside of it's most efficient zone at high rpm, or use a small turbo. If you guessed wrong and got to much power, you could use an intake restricter to kill the top end.

I would have to look at the rules again regarding FI, but either of these approaches might be more cost effective than building a 240 hp NA motor. It was also unclear to me if they use WHP for their 240 hp limit. Chris? Mirko?

Great projects. I wish there was a class like this out here. Milanos are classed very poory in the SCCA. You can run them in ITS, but you can't run coil-overs and you must keep the L-jet. At 2900 lbs... Racing against 2400 lb 240Z's. The only Milano in my region in finishing 2nd to last in every race. I checked. However, the E Production GTV6 is killing everybody in his class. :D

~Chris
 

·
Registered
Joined
·
623 Posts
It was also unclear to me if they use WHP for their 240 hp limit. Chris? Mirko?

I wish there was a class like this out here. Milanos are classed very poory in the SCCA. You can run them in ITS, but you can't run coil-overs and you must keep the L-jet.
ST is based on WHP, with dyno sheet required for registration/tech inspection.

Take a look at EIP, it's a good production class that requires much of the stock components and I believe a 2650 weigh minimum. That was the first class we looked at. Mirko
 

·
Registered
Joined
·
173 Posts
Eip

Hey Mirko!

It seems that your project has inspired me. :p I am spending a lot of time reading ICSSC, NASA, and SCCA rule books!

Maybe I missed it, but I thought ICSSC Imrpoved Production classes used SCCA Production rules. If so, the Milano is not classified in EP at all. The GTV6 is with a minimum weight of 2300 lbs and "level 2" preparation. This means 1.2 mm overbore, .445" valve lift maximum, 12.0 to 1 compression, and no porting.

Buy comparison, an EP Alfetta runs any cams, porting, any compression and 1950 lbs. This seems a better configuration. Same tires, same brakes, same suspension, 350 lbs lighter, better power to weight ratio. No coil-overs though in any SCCA class. You must run the original type of springs mounted in their original locations.

There is no one in my region running an EP Affetta, but the guy with the EP GTV6 is 5 seconds a lap faster than anyone else in EP this year at Carolina Motorsport Park...

Out here, my choices are NASA or SCCA. ICSSC in in the PSW only. Their is no ST type class here.

Back to your cars: :D

You might want to contact Alfar7 about engine options. 240 whp is right in the heart of what he has done with 3.0 V6 engines with 164s pistons stock rods, milled heads, porting, his custom cams and stand alone engine management (megasquirt for him, but you already have that covered). He can probably deliver a very torquey motor within your whp limitations by playing with the LSA on the cams he designs for your application. You might find this as cost effective as forced induction without adding more weight over the front wheels. This is a reliable street motor on premium fuel. No worries developing a turbo, etc.

Also, if you go over 240 whp, I think you can just add a little ballast (in an advantageous spot) instead of playing with restricter plates.

Thanks for the Alfa racing input. We need to get more Alfas out there. Thanks also for the very informative thread.

~Chris
 

·
Registered
Joined
·
2,984 Posts
hmm it has been many years but I had a set up in EA that showed a perfect flat HP using a roots I thought I had it configed that way but my memory might have failed me here.
I also found a cam config that would give a flat HP curve NA
I sent both results to a friend that was racing in the vett class with a rule like that.
but that was many years ago.

But I guess if done today I would use electronics control it. a boost controller can do wonders. I bet if the throttle could only open so far that would help too.
many ways to skin that cat.
But the key to to have a flat HP curve just under the limit. The flatter you can get it the more usable RPM range you get. The big blocks were getting the flat curve just a tad past idle all the way to red line (which is very low on a big block)
so you tune for peak at low rpm and de-tune after that to keep it under the limit.

The end result is a car that drives more like a electric car. and not needing to shift very much if at all.
 

·
Registered
Joined
·
623 Posts
Maybe I missed it, but I thought ICSSC Imrpoved Production classes used SCCA Production rules. If so, the Milano is not classified in EP at all. The GTV6 is with a minimum weight of 2300 lbs and "level 2" preparation. This means 1.2 mm overbore, .445" valve lift maximum, 12.0 to 1 compression, and no porting.

You might want to contact Alfar7 about engine options. 240 whp is right in the heart of what he has done with 3.0 V6 engines with 164s pistons stock rods, milled heads, porting, his custom cams...
Yeah, this is why Chris and I ultimately went with ST (Sport Touring) and not EIP (E-Improved Production). We noticed that GTV-6/Alfettas were included in the Production classes and thought that we would petition to get the Milanos in, using the argument that they were practically the same car mechanically. I think we're going to have fun in ST no matter what. Thanks for all the comments.
 

·
Registered
Joined
·
173 Posts
EP vs ST

Mirko-

Your ST Milanos will be much faster than an EP GTV6. I don't think it is possible to get anywhere near 240 whp from a 12.0 to 1, .445 lift, unported 2.5. 200 whp would be a miracle. The EP cars are also limited to 15x7" wheels when you guys can fit up to 10".

I am curious to see what rear camber and toe you and Chris decide on for your De Dion modifications and how you brace it.

~Chris
 

·
Registered
Joined
·
157 Posts
Discussion Starter #18
DeDion ideas and such.....

Yes, the power will be down in my car for some time. However, this does not concern me just yet. The goal is to get the car out on track, test & tune it, then turn up the power.

As for the rear of the car, I'm kicking around the idea of an aluminum dedion. Use a small upright that has four mount ears, two top and bottom. Potentially mount the lower as a fixed attach with heim joints, and make two upper links that would permit camber and toe adjustments.

This crazy idea is going to take some time. Meanwhile, it's a stock dedion for me.
 

·
Registered
Joined
·
173 Posts
164 front hub assemblies?

Chris-

I have seen pictures of fancy carbon fiber adjustable de Dion tubes for these cars, but I figured you would cut, bend and reweld yours something like Jes did for Roxanne. I am not sure that Roxanne's de Dion tube is not flexing significantly though. In the pictures, it still looks positive at speed and he is running a ton of static negative camber on Ron Simon's advice. IIRC, the SZ was set at -1.0 degree in the back, but it is a different design. Your approach is more ambitious.

But... you got me thinking... what if you use 164 front uprights and hubs? You cut the bearing carriers off the de Dion and weld a tab for the 164 lower ball joint. Then fab a bracket that is bolted to the upright where the strut attaches in the 164 that will receive an upper ball joint. The upper ball joint is bolted to bracket that will be attached to 2 arms, one behind the half shaft and one in front. The first arm attaches to the de Dion tube (behind the half shaft) and the other arm connects the trailing arm portion (in front of the half shaft). Both have rod ends and are adjustable (camber). The toe would be adjustable by similar rods from the trailing arms to the steering arms. IIRC, the rack on the 164 is behind the wheels, so you would need to swap the uprights from right to left. The bonus is that you get outboard 164 brakes on the rear. :D

This setup would be tuneable, but somewhat complex. It would not be legal in any SCCA class, but in ST you have more freedom. Let me know what you think...

~Chris
 

·
Registered
Joined
·
2,984 Posts
Is there some 164 pics to go with that? I can't quit follow not knowing what the 164 parts look like.

I have wondered when the de Dion tube flex does the flex help or hurt?
I would think under a hard turn it would flex in a way that give more negative camber?

But one thing I have noticed sprinkled about on the bb etc. is the watts need to be kept low and the uni-ball (tip of the triangle) need to be raised if the car is lowered or should I say the angle of the de Dion changed front to back .So raise the front equal to the the amount the back of the triangle is raised to correct that angle change.
or else you get squat/dive problems.
It seems the way alfa did it as far as I can tell was to keep the triangle at the stock height. and have more of a offset where the wheels attach. and also added the camber adjusters at the same time to the wheel offset part.
Photo 1 and 2
 

Attachments

1 - 20 of 49 Posts
Top