CIS to EFI any suggestions?

[Bobboloo]

Hi guys,

I just picked up a complete 84-89' Carrera intake system w/ Motronic brain. I'm going to install it on the 87' Carrera motor that's in my 73' Targa.

At present the 3.2 has 79' CIS induction with 74' type exhaust (later flanges welded on) and a stock 2 in 1 out muffler.

I'm thinking a Steve Wong chip. Any other ideas?

What exhaust should I go with keeping in mind no emission tests?

Should I see a sizeable performance gain over the CIS?

[Carrera3.5L]

Originally posted by Bobboloo
Hi guys,

I just picked up a complete 84-89' Carrera intake system w/ Motronic brain. I'm going to install it on the 87' Carrera motor that's in my 73' Targa.

At present the 3.2 has 79' CIS induction with 74' type exhaust (later flanges welded on) and a stock 2 in 1 out muffler.

I'm thinking a Steve Wong chip. Any other ideas?

What exhaust should I go with keeping in mind no emission tests?

Should I see a sizeable performance gain over the CIS?

I think Steve's chip should be first on your list once you have everything properly sorted.

Extrude Honing or polishing/welding the intake plenums shows some power improvement in the mid to high rpm ranges and will also provide more equal airflow into the cylinders. Not a cheap mod to do for the gains received, but since the plenums are off and haven't been installed yet...

You may also want to consider boring the throttle body, it may or may not make a difference, haven't seen any real data to support either way. Another mod to consider simply because it is off the car and hasn't been installed yet.

I run George's headers on my 3.2L based motor but you may want to retain heat. With your 3.2L, I would look for 1 1/2" or 1 5/8" header diameter if you don't already have that. A street muffler is personal choice I think, aesthetics and sound seem to play just as an important role as horsepower gains (or losses).

If you don't care about decibel levels for street use, my buddy Jeff Heywood at Coast Fabrication (www.coastfab.com) makes impeccable lightweight stainless mufflers that make great power and the mufflers can be easily disassembled and repacked. He supplies CART, IRL and many midget/sprint applications. Too loud for me for street use, but would be my choice for track mufflers. Coast mufflers are not cheap but you do get what you pay for in this instance.

I don't know what you mean by a "sizeable" gain over CIS, but yes you definitely have the potential to extract more power than CIS. Somewhere around 210 whp would be what I would realistically expect with the above mods and 91 octane. Would be plenty of reliable, smooth running fun in your early car I would think.

I think you'll be happy to ditch the CIS in favor of Motronic (if it was a cheap purchase for you) and there's no reason to put carbs on unless you do a piston and cam swap anyway.

Ralph

[Bobboloo]

Hi Ralph,

I read some of the past threads that recommend the extrude honing but I'm not sure how long I'll keep a shared plenum intake so I'll probably just leave it as is for now.

Truth be told the CIS actually runs surprisingly well and I have absolutely no complaints. I just came across a deal I couldn't refuse on the EFI setup so I took the plunge. This is one of those "while your in there you might as well..." kind of querys.

So, the HEs' are 1 1/2". I was afraid they might be to restrictive but this is a street car so I guess I'll be alright. I don't mind trading off some top end for good street manners.

I'm not a fan of loud mufflers (oxymoron?) on a street car. It draws to much attention. If this was a track car I would be all for it but such is not the case. I wouldn't mind a muffler that weighed less but I do like the sound of the stock unit (early style).

Maybe sizeable was the wrong choice of words. Noticable is a bit closer to what I meant. I would reconsider doing this if there was too little to be gained.

I think 210 whp is worth the effort and more than enough to get me in trouble. Considering that my tranny is the original 73' 915 mag 7:31. Making this motor much beefier at this point will just eat the tranny without any mods to it. The thing I'm really after is a motor with good manners that has a nice broad torque curve.

I agree completely that carbs are a waste of time without a change in cams and pistons. Even with a change in cams and pistons I still wouldn't do it. I'd rather go ITB's and EFI.

I have a set of 2.2 MFI stacks I might use for ITB's in the future but that would be ways down the road since I've promised myself I would finish my 71'S project before going with anything exotic on this car.

Well I think I've got a plan. I'll need a bung for an O2 sensor, an EFI fuel pump, filter, lines, fittings etc. Whoopee my first EFI 911!!!

[dd74]

Hey Bobby - bring that car with the 3.2 by the studio in Hollywood when you get it sorted out. I'm still holding out hope for a 3.2 something, short-stroke or otherwise unless I opt for a 3.6. I'm more curious than anything at this point, especially since my 3.0 is running strong.

You have anything upcoming with Icon/Departure films over on Seward?

[Carrera3.5L]

Bobby,

You should consider putting the car on the chassis dyno (if you haven't already) before you remove the CIS in favor of Motronic just to compare potential gains/losses.

Your exhaust choice should already be an improvement over the standard 3.2L exhaust that has to be routed through the catalyst. 1 1/2" header diameter should be fine for street use (as well as saving you some money), with stock cams the motor isn't making power over 6,500 at most anyway.

Try to arrange to have Steve present to tune the motor on the dyno after the Motronic is installed and functions properly, some nice gains can be found simply by dialing it in to your individual motor's requirements. He'll make your AFR look like the flatlands of Kansas instead of the Rockies. IMO it's worth every penny of the extra dyno time.

Ralph

[Bobboloo]

Dave,

I'm sure will meet up some place this summer and your more than welcome to drive the car. I'm planning a trip to TRE in about a week to get the suspension redone. The car is at SUV ride height and so I'm going to have them lower and corner balance it and "while your in there..." you might as well install these Wevo springplates, 22/28mm hollow torsion bars, Carrera control arms, brakes and swaybars. Yes, it's a slippery slope alright. I just wanted to lower the car and next thing you know I bought all this suspension stuff.

Nothing coming up immediately at Departure. I heard they were rebuilding after the roof debocle.

You should consider putting the car on the chassis dyno (if you haven't already) before you remove the CIS in favor of Motronic just to compare potential gains/losses.

Ralph,

I was thinking the same thing. It would nice to have the data for the Pelican board.

Try to arrange to have Steve present to tune the motor on the dyno after the Motronic is installed and functions properly, some nice gains can be found simply by dialing it in to your individual motor's requirements. He'll make your AFR look like the flatlands of Kansas instead of the Rockies. IMO it's worth every penny of the extra dyno time.

Have you been to Kansas? Nothing can possibly be that flat.

Having Steve dial it in would certainly be nice but I may save that for stage II. (ITBs ) I'll see if he has a map that is designed around my current components.

[Carrera3.5L]

Originally posted by Bobboloo
Have you been to Kansas? Nothing can possibly be that flat.

Having Steve dial it in would certainly be nice but I may save that for stage II. (ITBs ) I'll see if he has a map that is designed around my current components.

Yep, Topeka back in the IMSA GTP days with the 962's. You should see my AFR after Steve got through with it. Flatlined from 2,500-6,840. Motor is smooth as silk and pulls my heavy car and a$$ pretty well.

Steve should have basic mapping for just about every conceivable 3.2L combination by now. I still think that you should have him tune the motor on the dyno when the induction swap is finished, especially since he is local. I know of guys back East that would almost give their firstborn in exchange for him to fly back there and get their motor's optimized.

Ralph

[Bobboloo]

I'll share my Kansas experience. In the late 70's I was in a rock band touring and we played once in Liberal,Kansas (still not sure why they called it that)

Anyway my mom was from Kansas and told me I should drop in and say hello to my aunt Velma and uncle Clayton (alfalfa farmers who I'd never met) near Garden City. Well what can I say, it was awkward to say the least. Imagine this skinny kid with real long hair trying to make small talk with relatives he could barely understand because their drawl was so strong. It was one of several of my Spinal Tap moments in my life as a rock n' roll drummer. Well, I finished my iced tea and got the hell out of there.

Anyway, where were we.

Maybe i should do a dyno tune. I'd enjoy seeing Steve dial in an engine.