CUTLASS Trans for full LSA swap?

[JustBoostin]

Terminator monitors knock very well. The issue is that the knock sensor is not tuneable, or I should say the terminator will not allow for tuning of the knock sensor. The factory knock sensor are tuned for a stock motor, so if you do much of anything to the motor other than run it in stock form, the knock sensor is somewhat useless. This includes cam, solid motor mounts, spinning it 7500rpms, etc.

And Northernregal is spot on, by the time your sensor registers knock it's too late. I've used tunable knock sensors and they're pretty neat, but roller rockers, big cams and lots of rpm's are demanding on those as well.

If you want to monitor something worthwhile, then monitor coolant system pressure. I'm yet to do it, but it seems to be that prior to lifting a head coolant system pressure rise is noticeable and tunable.

Regarding the Terminator, be advised it has only 4 inputs and 4 outputs available. This is fine for many builds, but I'm currently down to one open input and all of my outs are used up. And this is after having to repurpose the fan output - I put the fan on a thermal switch.

I guess what I am used to is how dsmlink does it. The ecu looks at knock retard and allows you to program when the light turns on based on the number of degrees of retard. Most run this around 5 degrees, I go for 2. I’ve done this on 91 pump and E and had terrific results. Even with stock rods & cast pistons with 25 psi on E or 15-18 psi on 91 pump.

now I will say this will be first time messing around with a boosted V8. Also my first time with a supercharger. I’d prefer a turbo set up, but I’d like to eliminate some of the complexities in favor of reliability for some road trips.

I guess I had imagined things being similar (boost level-wise) when it comes to knock threshold but I also haven’t had 7 other cylinders pushing a piston up either

 

[Northernregal]

 

[64nailhead]

I’m not 'in the know' what the reason is why the knock sensor is less effective. My comment, and I believe Duke’s as well, is only a warning - if you go with a Terminator, then don’t tune up against the knock sensor.

Regarding the difference between a blower vs turbo build, I believe it’s the exponential power increase situation. Boost and HP with a blower is quite linear in relation to rpm, whereas a turbo power development is extremely exponential. Turbos hit like a sledgehammer - the moment of uh-oh is over before ‘oh’ is out of the uh-oh comment.

 

[mclellan83]

I'm very jelly, LSA was my original plan for the Monte. I made the mistake of buying the TR6060 first cause I got a good deal on it then ended up selling it because I was looking at buying a wrecked ZL1 to just pull the whole shabang and decided what was in there sounded good enough for now. Looking forward to seeing this come together, nice Talon too. The old mechanic we had at our shop was into them, he was building a first gen that sent him through the ringer since he was trying to daily and work on it as he went. He ended up too frustrated and just sold it to a Talon parts guy who was parting it out before he even had it in hand

 

[81cutlass]

Hello fellow Minnesotan.

I'd recommend a 4L80e, or a 6l80e since you can get a factory pcm to control that with an LSA.

6l80's are a bit thick around the tailshaft however so they need the floor pan cut out to fit.

A th400 is going to be annoying going to BIR or 75 down I35.


The reason people don't tune with the knock sensor is that it's 'on the edge' and really only a save me function in the computer from catastropic engine damage. There is power lost between peak HP timing and start to knock timing.

Say you make 550hp at 20 degrees of timing, 23 degrees makes 538hp and it's starting to knock and the knock sensors just start to catch it. 25 degrees makes 505hp and it's snap ring lands level of knocking. If the knock sensors are being relied on and react slowly one day, you will send those nice LSA internals into a milkshake.

What I have done is to go to the track and start at 12 degrees and add timing until the car doesn't pick up any more trap speed. Or, you could go to one of the LS tuners in the metro area (CJ tunes or Kiehne in Rochester) and get a great one.

 

[JustBoostin]

I guess what should be noted is I don’t tune “against the knock sensor”, I tune by AFR and EGT and usually run it on the fat end with 91. (11 or 11.5:1, boost dependent) If I do see knock, I adjust timing or fuel depending on RPM/AFR.

This thread does confirm my original thoughts, 4L80 is where I’ll find my strength and reliability.

on a side note, it’s my experience that when tuning with E, more should watch EGT. E may be very forgiving when it comes to knock, but damn it will still get very hot

 

[64nailhead]

Glad you received the info you were looking for.

I’ve only been around one build with egt’s and I’ve found them to work best as a reference for bank balance. I generally tune via plugs 1st and AFR 2nd. Whatever works for you is what you should continue to do, especially if it’s been effective.

Good luck 👍

 

[MissBreezy]

Recently picked up an LSA for my 84 Cutlass. Plan is for this to be a driver, automatic, pump gas, cammed, 15-18 lbs of boost.

So, I’m wondering, what trans? I’m told 4L80’s are heavy, both physically and rotational weight. I hear 4L65’s are another option?

Yikes! The 4l80e is huge. I'm having fitment issues putting one in my 6.0l LS swapped Malibu but the additional gear is going to be worth it (I hope!)

 

[Injectedcutty]

Yikes! The 4l80e is huge. I'm having fitment issues putting one in my 6.0l LS swapped Malibu but the additional gear is going to be worth it (I hope!)

What issues. I as well as others here have 80E's in our cars. Yeah it's tight, but so far I haven't had any issues. I do however have new body mounts so that might make a difference on the topside clearance.

 

[Northernregal]

Yikes! The 4l80e is huge. I'm having fitment issues putting one in my 6.0l LS swapped Malibu but the additional gear is going to be worth it (I hope!)

If its tight you have bad body bushings or rusted out bushing holes.