Posts by iNewton

@Casey_SS

You are mixing the terms Canbus and OBD2.

Obd2 is a comm protocol for externally accessing the ecu and Canbus components.(aka laptop connecting to vehicule).

Canbus is a comm protocol between different modules in a vehicule (aka ecu to stability control module to abs module etc). Its not used to connect to a laptop.

The OBD2 port on the SS is not standard therefore it won't talk to OBd2 readers out there that are not wired and programmed for the Sling. Mefiburn has a software and plug for the SS that works, and will log to a laptop for a while.

The Haltech ECU can communicate with the other modules in the Sling over canbus, so it will work with stability control and throttle control unit (which is not in the ecu itself, its in the power steering unit) and also ABS will work.

Other functions managed by the ECU like cruise control doesn't work for now, and if you switch to a canbus dash, fuel level, warning lights (check engine, high beams light etc) and flasher lights (in the dash, outside flashers will work) won't work unless you wire something to make it work.

You can keep the stock dash and work with the Haltech Ecu, in which case you would only loose cruise control.

The haltech 1500 has some limited logging capabilities by itslelf, but can be connected to a laptop while running and you get unlimited logging.

@QuickSilverSS

Well for sure with the right funds anything is possible, my reply was targeted as why we don't see more super high end kits like the twin turbo FF is making, and my answer is that its because of the quickly diminishing results of going crazy with uber high end stuff on the SS.

On a nornal car, you could play around with front / rear weight ratios, you could make a roll cage, stiffen up the frame, modified suspension geometry (not just shocks) to help put down all that power, so putting money on details to help with standing launch, better power modulation etc. is worth it.

On the SS we are stuck with a pretty lousy frame when it comes to performance. Center of gravity is high (from a high performance poibt of view), suspension geometry is pretty fixed on the front and rear is untouchable unless you spend some crazy moola, so besides getting better shocks, your options to help put power to the ground and cornering is fairly limited.

Thus the lack of interest for high end kits because in the end, for 90% of the people, the difference between a 20k drive train and a 8k drive train is 2% more "real life" performance.

Yes you can have a 600hp sling, but compared to a 300hp sling its not gonna be that much quicker. Both with burn the rear wheel up to 3rd gear so acceleration is going to be pretty close, and into 4th gear and 5th the wind resistance and shit aerodynamic of the SS will make it scary to push beyond a certain limit because its just not made for this.

In order to make a SS a real performance machine you have so much cash to throw into it that it makes no sense to go there unless you sre a fab company trying to show off your skills.

At some point your just better off buying a Xbow or a Ariel Atom vs modding a SS for 80k.

@Tango one wheel with good weight distribution would be much better grip. SS weight distribution is front heavy and that affects rear grip a lot.

And two wheels with a differential is effective at finding grip vs one wheel.

Quote from lrobbi

... you might be on to something... I just wonder if the "market" wasn't ready for this setup yet. Maybe later as more and more Slings are modified on a very high end, this could come back. Right now it could be "Priced out of this market" - no disrespect to Shawn at all but maybe the market is not ready for it YET.

Its all about traction.

The Sling with its single wheel in the back is severely traction limited, and while a setup like this might look amazing ( it does) anything over 300hp at the wheel becomes useless fast on the Sling.

Its hard to validate shelling out 8/9K on a twin turbo kit to hit crazy numbers when your rear wheel is constantly spinning.

Also to make any kind of power over 300hp, you need a forged engine, so add another 4k in the mix, the twin turbo will surely require a custom ecu to make use of solenoids for boost control, so add another 3/4k for the ecu and tune, and then the stock fuel system is not up to the task either, so another 1k for a fuel pump, rail, hoses, regulator etc.

So overall your looking into putting close to 20k into a drive train that will give only limited return vs a setup that will cost less than half the price (aka Alpha turbo on built engine on stock ecu / fuel pump), because in the end both will spin the wheel on demand, with little to show as far as performance is concerned.

@sideseatdriver submarining is not more of an issue with a 4 point than stock belts.

The fact is that in a front collision, a 4 point harness is more dangerous than oem belts on stock seats. Of course if the stock belts break because they fail, this is a very bad situation.

Yes the 4 point will keep you planted in the seats in hard driving, but they are dangerous in high G front impact.

Installing a proper 5 point requires to have a seat made for it which has a slot directly under the crotch area (cannot be placed at the edge of the seat), a proper welded hook point on the floor which is $$$ and usually means that the seats cannot move front to back anymore, and is hard to adjust for different driver sizes.

Overall, its more about being safer for most of the situations you might get into. 4 point with stock seats can make a bad situation even worst making a dangerous accident into a deadly accident.

4 point on sports seats is much safer than stock seats with stock belt, 5 points with race seats is very safe but not very practical for daily driving or multiple drivers.

You lost me at "I can't see anything in the rear view mirror".

Pretty sure its not light related

Leprechauns probably. These little shits !

I hope any of you thinking of installing a 4 point harness won't do it using stock seats.

This can be even more dangerous. Harness must be used with racing seats that have the openings to keep the straps in place and over the shoulders in a frontal collision.

Stock seat don't have any way to keep the straps from putting pressure on the shoulders in a frontal impact which can be fatal if the hit is strong enough to compress the spine by pressing down on the shoulders.

5w/30 is fine unless you race the crap out of it.

Thicker oil is not the best for turbos usually and unless you have wider clearances on your crank and conrods, there is no reason to go thicker.

The way I see it also with the VvT cams is that thicker oil might slowdown cam phasing response because of the extra weight of the oil, though this is just me maybe overthinking stuff.

Quote from jluna317

Engine finally sounds normal drove about 200 miles from mass to lake George and everything sounds and feels a lot better let me know what u guys think

Yeah that sounds a lot more reassuring lol

What exactly dis you replace to get to this point?

Quote from Dave@DDMWorks

The oil pump is driven directly off of the crank.

Wasn't all of the chains and guides replaced with the new engine build?

What he just said, although it's actually driven by the harmonic pulley on the crank, not the crank itself. (Note to Dave, was not trying to be a smartass or correct you, I know you know, just wanted to be more specific for anyone reading...)

which brings us back to asking the builder for a spec sheet of exactly what was done, parts list and clearances used. Else you will be rebuilding that engine for the next 6 months replacing one stupid bolt at a time trying to find why its knocking or breaking or sounding like shit.

Pistons are shipped with a spec sheet with the order, so getting this should be easy. You want to know this list of things:

Piston to bore clearance
Piston to top deck clearance
Ring gaps used on top and middle rings
Conrod big end measurement for both x and Y axis (you want to make sure they are round)
Crank journals measures X and Y (this will give you the bearing to rod clearances. This will determine if you are using 5w/30 oil for stock clearances or heavier oil if the clearances are more than stock oem specs).
Bore measurements at 1 inch from the top where piston is at TDC where the rings are I messure the center of the bore and down the bore where the piston is at the bottom, measures should be taken front to back of the bore (same direction as the piston's wrist pin) and left to right (which is the thrust face of the piston when rod is pushing the piston up and pressing the piston against the wall) from there, determine if the bore is out of round, tappered or has a bulge in the middle of the bore and take corrective measures (either bore the cylinder to match the biggest bore of the 4. What is the bore size of the engine now?

Was the top deck and head surface shaved? If not was the measurements taken to insure both decks are straight and within specs for the headhasket being used? If its been machined, how much material was taken off? If this is a lot, it might show the engine has overheated in the past. Can also affect your compression ratios if a lot of material was removed. They shoudl provide you with the deck height measurements too.

Where the cams removed? Valve seals replaced? Lifters drained and checked for problems? Rockers same thing... valve guides replaced? Did they use the GM MLS headgasket ?

Anyways there is a lot of details we don't have on what was done to this engine, not sure if its common practice in the market to just ship an engine block to a client with zero information of what was done to it, I hope not. Its crutial information for the day you run into problems and start looking for solutions. Without these specs, you have nothing to compare with the day you teardown the engine and try to determine where that oil pressure drop is coming from or where that knock is coming from, you can't determine what wore prematurely if you don't know what size the orginal parts are. Stock engine will use the specs of the mecanical handbook of the engine but with aftermakermt gear, there is no way to trust the parts if they have not been messured, weighted and all data writen somewhere for future refernce

You should get an oil pressure / temp gauge installed on the head while you are in there.

Oil pressure will tell you if everything is running as it should, your oil temp will tell you if the engine is ready to play or if you are too cold or overheating which is important with a turbo, Boost gauge will tell you that you are not overshooting your boost target and risking throwing a rod and AFR will tell you if you have fuel issues like a weak pump which can kill your engine realy quick.

With the kind of build you are doing, these are a must in my opinion, but that's just me.

Innovate has a nice boost / afr gauge and dual function oil pressure / temp gauge in the MTX series.

Of course if you are swapping your ecu, you could just wait and get the Haltech wideband controller along with oil temp sensor and hook it up to ecu for logging purpose, though unless you have the IQ3 dash you wont be able to see the date in front of you.

@jluna317 broken plugs ?

Did you check the plugs and pistons for contact? That males no sense at all.

The manifold is not very nice but there is no reason it would make so much of a difference for boost to the point where you are wearing out bearings and breaking plugs, to me that is totaly illogical. Something else is going on in that engine.

Is it your original engine that got forged or did you purchase the engine complete and already built?

Not trying to be a dick here, but seriously ,considering Alpha has not been building ecotecs for very long (compared to DDM or Hans) I would ask for measured specs and details of what they did down to torque used for every bolt when they built the engine, especially if they got a used block from totaled car and rebuilt it.

If they can't provide this that means that it has not been verified and to me this engine would be worthless, because there are so many things that could have been setup wrong you will be chasing gremlins forever and no one will be able to help you out without doing a complete teardown of the engine and make measurements.

Worn bearings, broken plugs, rods knocking and possible piston slap on a 5k miles engine makes absolutely no sense at all. This to me sounds like an engine that was just torn down, swapped rods and pistons, got bores honed a bit, adjusted ring gaps and put everything back together with nothing else done.

Where the cams removed during rebuild?
Where the hydrolic valve lifters drained before re-installing the cams? If not that could have bent a Cam on 1st startup (cuz lifters get hydrolocked and push on the cam).

So many little details that you need to check, just putting parts in and torquing bolts, thats not how you prep a performance oriented motor.

You might have worn tensioner or guides, streched cam chain, old oil pump, out of round bores, too tight rod / crank clearances, too much piston to bore clearance, pistons not having proper deck clearance, worn or improper crank to block clearance, bad crank thrust clearances, so many things to check when trying to figure this kind of issue out, you can't be just replacing parts without having measured everything and be sure you are in spec everywhere.

Again, my advise, as shitty as it is, would be to take out the longblock, tear it down and start from scratch measuring everything before putting it back to together. Its the only way you know for sure that it was done right, that you are in spec. In your case, that means builder takes responsibility for his build.

Do you have a oil pressure gauge? If not, get one and check oil pressure at the head. Worn bearings will usually make the oil pressure drop so its a good indicator.

@jluna317

Well, my answer is going to suck, but if the bearings are shot on two cylinders, you have a issue.

You will need to show pics of the bearings and also the crank journals, but premature bearing failure is normally caused either by bad lubrication, low oil pressure, incorect rod to crank clearances or severe detonation.

I would suggest changing your oil if the bearings are shot, as you probably have some bearing material in the engine now, and that is not good news.

How did you check for rod knock?

The "good" way of doing it is to remove the spark plugs, wind the engine (clockwise) until the piston on the cylinder your are checking is at the top and then just a bit more until the piston starts to go down a bit. Just a hair we don't want the crank to start traveling down, we just want the crank to start pulling down on the piston via the rod.

Take a flat long screwdriver (make sure its clean), insert it into the plug hole and push down on the piston.

You should have zero play. If the piston moves down and you hear metal hitting metal, your bearing for this piston is worn out and this is what you hear.

The bad news is that depending how long this has been happening, you might have scored the crank journals too, which means it would have to get ground or repolished depending.

The journals should be smooth and have no scoring marks on it. If you see any marks then its possible some bearing material got caught in there and damaged the crank. If you see bluish coloration on the crank journals it means things got hot in that spot and might mean rod end being out of round or clearances too tight.

Rod ends should also be checked for out of roundness and the rod bolts should be replaced if you can't verify if they are stretched or not. If they are you run the risk of one failing and that means engine destruction.

Anyhow, send pics.

Chain tension is not constant. It varies depending where the cams are on the lobes, sometimes its a bit slack sometimes its tight. This is the reason you have that guide between the cams to prevent the chain from poping out when tension slacks.

Again, I would advise against touching anything on the engine and contact the builder and get the opinion. Sound I hear from de video really sounds like mine but more pronounced. Understanding that different phones / environnements will produce different recordings, its hard to say if it really is worst or not, but at this point chain tension is not one of the things that would explain the knock and again, in the case where the cams really did skip, its too late, you would have bent valves and scored pistons as the pistons and valves interfere with each other on this engine when valves are open and piston is at TDC.

Yeah, this is easy to check, if you don't have a stetoscope, use a long screwdriver, just place the screwdriver on whatever you want to hear and place your ear on the end of the screwdriver, it should help you ID what sound comes from where.

Still, I would ask for the spec sheet for the pistons and bore measures that where taken from the machine shop.

If I am paying 3/4k for an engine, I want to know exactly how it was built, using what parts and what clearances where measured during the build. I want to know rods used, if the ends where measured and balanced, how much weight needed to be removed from where to balance everything.

Putting a performance engine together is not just taking parts off the shelf and scewing everything together. It takes planning and this information is critical for you to know.

Without this information, there is no way to know if what you are hearing is normal or not.

On a side note, I would never run pistons with a clearance of 0,006 for a daily driver. The constant start / stop of the engine will prevent the engine from reaching the correct expansion of the pistons and you will end up with an engine needing a rebuild quickly because the bores are going to be out of round.

I don't recommend playing with the chain tensioning, if it was loose and skipped a tooth, the engine would run like shit, and if valves made contact with the pistons, a simple compression test will tell you valves are leaking, and at that point, you have damaged pistons and bent valves and even if you where to correct the tension, engine is still shot.

Leave everything as is and let the builder figure it out. If you start messing with stuff, its more variables the builder can use to say its not their problem.

Start with getting a spec sheet for the engine build with part numbers, clearances used for pistons, ring gaps and crank to rods bearings and bringing this sound to the builder's attention.

I just listened again to your vids on my PC with headphones, I would check with the builder, that doesn't sound like piston slap to me, or if it is, sound way way worse than mine. My sound stops the second I touch the throttle and only reappears once engine settles on 750rpm idle, yours seams to follow rpm. I would check for rod play on the crank and check if your oil pressure is normal.

Mine also goes away completely once engine is pushed hard.

Also my engine did this since day 1, this is not a sound that appeared with time. The sound has not changed even after 2000 miles.

If your engine was silent and started doing this, it's definitely not normal and I would get it checked by the builder right away.

Anyways, my suggestion is to not take anything appart, contact your builder and let them handle this, unless you know exactly what you are doing, there is nothing you can fix with basic tools and the engine in the Sling.

Although a video will only get you so far, this sounds like piston slap to me.

Who built your engine?

You need to get the piston to bore clearance that was used to build the engine and type of material used to make the pistons (either 4032 alloy or 2618)

4032 has more silicon so less heat expansion (so tighter clearances, less piston movement. In the bore) its not as strong as 2618 which has increased strength but more expansion under heat so needs larger clearances which means more noise when engine is cold. The concept is once engine is under racing conditions the clearances will be in spec.

I have the exact same sound on mine on cold start and idle, my piston clearances are on the loose side because I intend to race it with 30/40 minutes of Wot on a very fast track and the clearances calculated where around 0.006 inches with ring gaps on the larger side. By memory stock piston clearances are around 0.0004 (yes, that is a zero more after the period, not a typo).

I have 3% blowby and 185 psi pressure in pistons on all 4 cylinders when engine cold so the sound is just an annoyance I am getting used to to have an engine that will handle 500hp at WOT for 40 minutes straight without seizing in the bore.

My engine on 1st startup after built:

What you are hearing (mecanical cause):

So this MIGHT be normal, depending on what materials used and clearances calculated by your engine builder where.

You should get a stetoscope and listen to make sure you are not in reality hearing rod knock (which means the rod bearings are destroyed and the engine is about to follow), which will come from the crankshaft area (down in the engine) vs piston slap which will come from the top of the block, just under the head).

If you suspect rod knock, you can easily check this without taking the engine apart with just a long flat screwdriver thru the sparkplug holes. I can explain how if you need or want to check this.

Don't start taking shit appart unless you know what you are looking for and confirmation the noise is not normal, you might just be causing more problems for nothing.

Keep in mind that piston slap in itself will not destroy a engine but will get worse with time to the point of needing a rebuild sooner that a piston with tighter tolerances because it will wear out the bores faster.

Again, check with your builder to see if the slap is expected or not, I was told that piston clearance above 0.003 on the LE9 would be noisy.

Quote from MiM

You're right! Not sure why I thought tens...

Are tens possible? @Tango, @TravAZ, @iNewton?

@rabtech? I know you aren't into the drag strip as much...

Not into anything drag tbh, but pretty sure to get into tens, some serious tought has to be put on grip and aerodynamic drag. The SS just gets to a point where around 210km/h you feel like the hood wants to rip off, then front end is all over the place and even if you had 1000hp its like pushing thru a concrete wall.

Quote from MACAWS

That sounds like a much cleaner install than other options.
Once you make your formal announcement I will call with a barrage of questions.

Yeah until someone robs it from there.

Not much use for a stock ecu but an aftermarket one is more interesting to steal. That's why I installed my Haltech in the glovebox, so it can be locked up.