jason's education thread

[TexasT]

.  Not one cool guy part on my car. 

I don't know, but I think T-Tops are pretty cool.

Im kinda a cheapskate. I use a crushed stock fpr. I keep buying the used stock ones for a LOT less than new. Now I've discovered thjs cool adjustable TT5.6 chip that came with the used 42lb injectors I bought. This is gonna be fun. Ive been reading over at the tt site. I cant wait til I find a used alky kit. And I really need to try that rjr spacer that hr doesn't think works. Such a wide new world of cool stuff.

[Scoobum]

If you're referring to the RJC Power Plate...beg, borrow, or steal to get one.

[Steve Wood]

Steve...here's a pic of me squaring off against a big tire car from earlier this year. High compression SBC...big cam...loose convertor...op en exhaust...big gears...blah blah blah. I'll give you one guess who got to the top of the track first. To head fake these guys even further...note the stock GN rims...and that's a 10.5 tire on the rear...clears the frame rails and fender lips.  Not one cool guy part on my car. 

That car is too ugly to compete

[good2win22]

What to do... Twice now I've had a reply written and its been dumped.


I'll write more tomorrow....

[nocooler]

Long ago,  Jeremy (Nocooler) was running mid-elevens on a TE-44 in a peg leg car...he put some serious air in the bag on the passenger side to hook it up

You can't go that fast with out a posi.......tha ts what everyone told me!

It was a TA49 too

Jason shoot for 94-95mph in the 1/8th that's where the turbo will be just about done. It'll take some fine tuning.

I'd put the PTE housing back on the turbo if you have a 3000rpm stall too!

[TexasT]

If you're referring to the RJC Power Plate...beg, borrow, or steal to get one.

Oh, I have one, I just haven't gotten around to putting it on the car. I never had the trans strong enough to add more pah, but now it is and we will be adding more.

What to do... Twice now I've had a reply written and its been dumped.


I'll write more tomorrow....

Compose your stuff in word or notepad or something then copy and paste it into the message place. This way you dont lose it.

[Steve Wood]

Or just copy it before you post so you can paste it back if you lose it while posting

[Scoobum]

I had a 49 with a .83 Precision exhaust housing. Wish I still had it. I'd bolt it on this engine and squeeze it for all it's worth.

[Scoobum]

Jason...this is what I would do. I'd bump the boost up to 25 PSI...and leave high gear fueling where it's at. The slightly higher boost pressure will lower your 02's for you. Log 2 shows 795 going through the traps...so your high gear fueling should be fine...if the temperature is the same. Pull some low gear fuel out of it...and have at it. I'm curious to see if your MPH increases...or you "blow through" that unlocked convertor.

Be sure to address that voltage issue first.

[good2win22]

Going to try to post again…
Nice kill of the SBC!
Cleaned the battery terminals and reconnected.  Getting a consistent 14.2-14.4 volts at the battery, alternator, and volt gauge at idle.  I understand that SM only displays voltage at the ECM.  Why the drop?  It’s not like I have 60 foot of wire from the alternator to the ECM…  Alternator on the fritz?  I guess I could pull it out and see what a load test says.
Laid down some rubber, looks like the optimum tire pressure for the most amount of rubber on the street is 17 psi.  Still need to look at tires after a few more launches to see if the left tire is wearing more than right tire, then consider bags/stabilizer bar for countering torque/twisting frame at launch…
What is a realistic 60 foot time to aim for? I know, the fastest I can get away with
What is a realistic 1/8 mile time/mph to shoot for? Again, the fastest without getting knock
How much boost have you guys put through an original engine without there being a failure?  I believe that I have the injectors and fuel pump to handle more boost but concerned with the head gaskets, heads being the choke point and efficiency of the  turbo.
I have a precision .63 exhaust housing for the turbo but some goober ported the waste gate hole way to low and puck won’t cover it.  Even tried and externally gated down pipe but had issues with the waste gate not opening at all.  So, I went back to the garret.  Having some issues with part throttle surge but just can’t bring myself to put a blow off valve on the car…  just something to “import” about it.
Not sure how to ask this… TA heads.  Better flowing, bigger valves, weigh less, and can be repaired easier than iron heads.  The thermal inefficiency of aluminum is the only con?  There has to be something else.  I can understand your car needing to be tuned after installing a set, you’re flowing more air with less resistance.
That’s about all I can come up with for now.

[Steve Wood]

There may not be sixty ft of wire between the alternator and the ecm but there are one heck of a bunch of connections.

On the plus side there is the cable from the alternator to  battery positive and there appears to be a joint in it about one foot from the battery.  Then there is the connection from battery positive to the starter post.  Then a fusible link from the starter post to the bulkhead connector.  then a feed from the connector to the ignition switch.  A feed from the ignition switch to the fuse block ecm-ign fuse.  Then from the fuse to the ecm connectors and from the connectors to the ecm guts.

The ecm takes the input and goes A to D.  The scan tool then reads this digital conversion.  Ever notice the scan tool number jumps around quite a bit while the voltage at the alternator is varying only a little and not in sync with the scan tool display?

Of course we should not ignore the ground side of the equation.  The ecm goes to ground to the case and to the back of the head.  From the head to the turbo mounting bracket support and from there back to the battery terminal.

Look at your shop manual.   

We all know that grounds are a potential problem but, beyond that, I have found that the alternator case to the engine can be a problem-especially if someone has powdered coated the alternator or painted the mounting bracket.   Then the ignition switch often has a problem at the connector as shown on my site and it is not uncommon to find a bad contact at the ecm -ign fuse terminals or green stuff at the ecm connector that carries the feed.

Take your meter and start looking for voltage drops across each circuit feed.  For instance, put your meter on volts, put one probe on the alternator battery terminal and the other probe on the battery positive terminal.  Read the voltage on the meter.  If it is greater than 0.100 volts, then you have a problem in that part of the circuit.  Normally, it should be a few hundreths.

I find it more reliable to install a volt gauge and tap it into the feed going to the ecm somewhere between the  fuse and the ecm connector.  If the voltage is good there and I have improved my grounds, then I find something better to worry about.

Ah, thermal inefficiency.. ..

Engines run on heat and it takes heat to spool a turbo.  We all know that.

When we go to aluminum heads we lose some heat and thus power. Normally it takes about 1.0 more compression to get back to where we started from when running aluminum heads.   Now, we can turn the boost up a couple of pounds and get lost power back on top end but we still have a car that needs more converter to get it moving off the line.  That makes a car that is slushier to accelerate in normal driving.  For a race car, it does not matter unless you get caught by the lights while you are still trying to spool the car.

Those big ports that flow so much air?  Yep, they work great on the top end but they kill velocity and again make the car less responsive to the throttle and less fun to drive on the street...again we need to get the rpm up to a point where the car will respond to minor throttle signals so we go to a big converter and we can get the turbo to spool at heavy throttle input but the car is a pig for normal driving.

Yes, cars with ported iron heads have run nines, but they would have gone faster with bigger ports...or at least they should.  But they raise the question, Just when do aluminum heads become a real improvement? I am guessing lower tens, but, that is just a guess.

Are unported iron heads a bottleneck?  Sure, but with a small turbo with a free flowing intercooler and/or alky injection, I would not be surprised to see this bottleneck be a fact until the car was at mid elevens, or lower.  Put a big turbo on the car along with a bigger cam, and this bottleneck might be in the mid 12's.

It's all about the total combination.  Put a set of aluminum heads on a stock block with a stock turbo and you get instant pig recipe.  Nitrous time.

There are lots of fallacies floating around the net and many have been propagated by guys selling parts.  We were all told that the  first magic part we needed to buy was a 3" downpipe.  I sent Turbocajun a turbo to try on his car that was consistently running 11.0 at 120 mph because he was only using a TE-60 turbo and we all know you cannot go fast with something that small.  He could not use it because his wastegate was too small...seems he is using a stock downpipe.  Yet, we were told we needed one to run twelves. smh.   On alky, a lot of us have run mid elevens on a stock dp.


Oh, yeah, that reminds me, doesn't Jason sell a larger puck that is made to replace a stock puck that does not cover the wastegate hole?

[daveismissing]

http://rjcracing.com/product/exhaust-systems-2/flanges-weld-bungs/

[good2win22]

Already have the larger puck and it still doesn't cover the hole.  I'll shoot a pick of it this evening.  I'm pretty sure it still has the red grease pencil markings on it.
What about cam selection then?  I have a stock set of heads that came off my spare engine. Could I, should I port those and work the bowls some? Would that kill the velocity by increasing the flow?  I can always throw more money at it like a bigger turbo, front mount intercooler, and use those aluminum heads and either deck the block or change pistons to up the compression. If the heads run cooler, why not take out the 160 thermostat and go with a 180 or higher.  I rarely see over 170 on the temp guage as it is now.  At least that way I could use the heater during the winter.  I'm more after the knowledge than throwing money at my problem.
I'll also post a pic of the very first quarter mile time slip.  It's taken over two years but I've come from the high 15's since purchasing the car to the low 12's.  This last second and a half that I'm chasing is killing my patience
 
what do you consider small and big turbos? 

[Forzfed]

Not much mph for the 7.85, did you let off at the end of the run?
Do they give you a 330' time n mph?

how much boost are you launching at?
Have you tried different pressures in the tires to get a good looking patch? Pressure you are using?

Do you know what mr jake did to the trans? parts mods etc?
I wouldn't lock it unless jake said it would be ok.

I was thinking the same.  i ran a 7.7@89 mph with an unopen motor and stock turbo/intercooler.  With a TE-44 and unopen motor in my higher milage car I was running 7.7@94mph with a best of 116.6mph in the 1/4.  This was with 18' of timing and pump and alky.

[Steve Wood]

I am guessing that a good pocket job, a little off the short side radius and port matching will give you about 90% of a full blown port job without any real loss.

Fastest I have ever seen on a stock cam is 10.4.  A mild cam will not hurt anything and it may help some as you get close to the tens.  Something along the lines of a 208 to 212 flat tappet makes little difference on the bottom end-particularly if you have a looser converter.

the biggest bottleneck on a stock engine is probably the intercooler if you put a larger turbo on it as there is a lot of pressure drop across it.  If you run alky injection, this becomes less of a factor but it starts showing up around mid elevens.  Dan (Grumpy) went 9.90's with a CAS V4 stock location which does not flow nearly as well as some of the newer ones like the PTE stock location and quite a few went into the nines on a stock and a half intercooler welded together along with the big neck mod.

Pushing air thru a restriction(s) is a lot easier than pulling it thru and that is the reasons forced aspiration is less sensitive to be cams, heads, etc than a n.a. engine.  I am not saying it does not help...just less crucial.

Your short times are good, I think, for the tires you are running.  At this point you are not losing much, if anything, to the tires.  Some people don't understand that hooking is one thing, but, having enough power to take advantage of the hook is another. It takes a lot of torque to pull better than a 1.6 short time.

I have noticed a lot of people trying to go fast that have engines, or drivetrains, that have problems but they keep buying bigger parts instead of working on the problems.  If you have low compression or 30% leak down, or a bum tranny, it will not respond to tuning or parts.

There is a big difference between the combustion chambers running cooling and the heads running cooler.  Those combustion chambers are cooler because the aluminum passed the heat straight thru to the water jackets instead of retaining it in the chamber.   170 degrees is about the temp that I have noticed the most power being made on the dyno.  I suspect we over think the cooling a bit.  If the car will hold 180 degrees on the highway in the summer time, that is probably plenty cool.

yeah, you can buy heads, pistons, cam, bigger turbo, front mount, etc., but, if you are still getting out run by guys with a lot less, it is probably not very satisfying.  Most people don't need that to run high tens, low elevens.