Hello,

Originally I was going to sell my 87 L-98 coupe and buy a C5, but after having this car for about 8 years, I have decided to keep it. Yes I know the C5's are superior cars, but I just like the body style of the C4's too much.

So with the $ I was going to spend on a C5, I am going to spend it on my 87 with lots of upgrades instead.

Basically, I am now prepping the car to use a 420 CID/Bowtie block/Brodix Track 1-23 Degree Cylinder Heads/LPE-Accel SuperRam kit/LPE 219 cam/11 to 1 compression ratio/full roller engine/strong 700R4 and hopefully should be built in about 4-6 months from now.

In preparation for this engine, I am going with 1 3/4" TPIS long tube headers, cats, and a Corsa cat back system. Swapping the Dana 36 for a Dana 44, R-D Racing camber brace, cross-frame and cross-bar, plus odds and ends like new radiator, front/rear suspension rebuild etc etc.


Now is where you come into this picture :)

I need your suggestions on....

1)recommended torque converter and rear gear ratio

2)recommeded front and rear suspension rebuild kits...coil-over conversion?
Stick with a transverse spring rebuild set-up?


Please base your recommendations on this....

A)This car is a daily driver
B)Car will be run occaisionally at the drags and I would like to try AutoX or the
like, but mostly just for fun and the "legal racing" venues as well as avoiding
embarassment on the streets.
C)This car is a daily driver

Thank you for putting up with this long winded post and thanks in advance for any input you may have!! :auto:

 

I would put either a Precision Industries or Vigilante torque converter in there. Don't waste your money with anything else. (I'm sure somewhere there is something that is good but these two are known, trusted and proved)
DO NOT USE A TCI CONVERTER

Since this is going to be driven on the street, I wouldn't recommend anything larger than a 2600/2800 stall.

Again, since this is a daily driver, a good rule of thumb to know what (actually you're doing it backwards if you already have your cam selected) gear to have is whatever rpms turn at 60 mph is basically where your cam should kick into it's powerband.

If at 60 mph, you're turning 2200 rpm, then the cam you generally should select should have a powerband starting at 2200... like I said, this is a general rule of thumb.

Your torque converter should obviously have a higher flash point than your baseline powerband number so when you flash the converter or stall it out, you are already in your powerband.

HTH's....

Mark





[Modified by C4 Newbie, 6:05 AM 12/16/2003]

 

Thanks for the response C4 Newbie. Based on your response and from what I have been reading in these forums and in peoples signatures, the Precision Industries Vigilante Converter seems to be the way to go (probably 2400 or 2600)

I went to their website, but it just says weight, gear ratio etc are the factors for selecting a stall speed, but thats it.

Hehe, I have been wearing out the forums search button on finding info on selecting a converter, gear ratio and suspension set-ups but the problem is most of the info is how to build for a certain application like drag cars, autocross, road racing, etc

Thats the problem for me, I want to set up my car for daily driving and a litte of all the different "racing categories" not to be the number one racer. Just an all-around kick-butt fun and reliable car.


That is why I am going with this engine set-up....

420 Cubic Inches: L98 motor

Lingenfelter 420, from Hi Tech Performance May, 1996

3.875" stroke Lunati 4340 forged steel crank

Oliver 5.875" rods

11: 1 compression, JE custom forged pistons.

Bowtie engine block

Lingenfelter hydraulic roller cam: 219/219 @ .050, .525/.525 lift. 112deg lobe sep, Comp Cams 1.6 ratio stainless steel rocker arms.

Lingenfelter CNC ported Brodix Track I heads, 67cc chambers

SuperRam intake, base, and 58mm throttle body, controlled by DFI using 30lb/hr injectors.

Ran test with Accel 1-3/4" headers.
RPM TQ HP
2000 435 165
2500 470 225
3000 520 300
3500 545 365
4000 560 420
4400 561 480
5000 535 502
5200 507 509
5500 475 490


This engine recipe seems to be a very powerful, yet very streetable combo that should be fun and reliable as a daily driver as well.

That is why I am hoping for some suggestions on stall speed, gear ratio and suspension set-ups because my car is being built as an all-around use kind of car and not set-up for a specific use, like drags, autocross etc

Anyway thanks for your time and for anyone else who may have suggestions!!
:)

 

TTT

I really could use some suggestions on the gear ratio, torque converter and suspension ideas as soon as possible. In fact, I want to order all the parts today or tomorrow if I could get some thoughts on this!

 

Larry,

quote
________________________________________ ____________

and hopefully should be built in about 4-6 months from now.
________________________________________ ______________

I remember the day I thought my combination would come together that fast
:lol: What's the lead time on those heads?

I'd recommend learning something about tuning while your waiting for those parts. I wouldn't trust the aftermarket chip tuners for a radical combination like your proposing. It's tuff to get the transmission setup up properly when your busy trying to figure out why the headers are glowing red hot.

It seems to make sense to do the tranny and engine at the same time but not that easy having your hands full with both. Don't forget the ignition system, throttle body, all aluminum radiator, etc... Aftermarket parts never go in as easy and quickly as you might think.

Good luck, Beth ;)

 

Actually, it depends on the time of year.....

I ordered my set of T1 M2 227's and got them milled, CNC'd for oversized valves and spring pockets done and they were at the machinists in less than 3 weeks.

Brodix doesn't have the same issues that AFR does with delivery times....

 

Well the Dana/exhaust trans swaps are being done as soon as possible and I won't be worried about the engine build till later (thanks for the tip on planning for lead times)

So I am thinking of going with 3.54 gears and a 2600 Vigilante. Sound like a good combo for daily use?

 

Just for the record. My '95 is running a 355cu.in., .586 lift cam, .322 (advertised duration, I think at .050", it's mid to high 2's) ported and polished heads, 1.6 roller rockers, 58 Throttle body, 32 lb. injectors, shorty headers, the Precision Industries 2800 converter with 3:54 gears.

Though I haven't dynoed it yet, it is my daily driver. It's snappy, hauls butt, and if I can keep my foot out of it, will easily break the 18-20 mpg mileage. Of course, it's almost impossible and usually 13-15 mph is more realistic.

I hope that helps answer your questions...

Mark

 

Yes it does Mark! Your cam is more of a "RPM" cam than the one I am planning on using. So this makes me think that maybe I should consider a 3.45 gear ratio instead. That plus with the 420 cube torque monster I will be going with still makes me wonder about going with a 2600 stall. What do ya think?

 

Well, I gotta tell you. I'm not afraid of running steep gears. I've got a blown, big block, tubbed S-10 with 5:13 gears as my fun car to drive. (in process of being redone now...)

Point is, for an automatic, I would normally run 3:73's or 4:11's. Because I wanted decent gas mileage, I chose 3:54's in the corvette. I have to tell you, it's plenty, almost too much... with the engine built and converter, you won't need any more gear.

Just my .02 worth...

Mark

 

Thanks again, guess I will go with 3.45's or 3.54. what do you think about the 2600 stall with a 420 cube engine?

 

Thanks everyone who posted suggestions for rear gear ratio's, torque converter stall speeds and suspenson mods for my application!

For my set-up, guess I am going with a Dana 44 w/3.45's, Vigilante 3200 stall and a few suspension upgrades

After I make these changes, I will make a signature for my posts on these forums to reflect the mods. Hehe, I look forward to people reading my sig and asking "Why did you choose that stall, I would have used xyz instead! Or why did you choose those gears?? I would have used a xyz gear ratio instead!"

Ah well, its all good, in the end this car should be pretty fun!! :)

 

lallend,

I had your exact engine combo with 3.45s and a Vig 3000, went a best of 10.93 @ 125, streetable, thru the mufflers with 10.5 ET Streets. That was in yucky Aug/Sept. weather.

Dave


[Modified by hookedup, 11:46 PM 12/18/2003]

 

Thanks hookedup, that's the kinda info I was looking for. I will stick with the 3.45 gears and after talking with LPE about the torque converter, they recommended a 2800 stall for my application.

Maybe like you, I would do better with a 3000 stall but I think your car was probably setup primarily as a drag racer instead of a daily driver. I guess I will end up in the high to mid 11's, but your 10's put a smile on my face!

Anyway, thanks for the very informative post! :thumbs: