Ramblin's

[ChrisCairns]

Just got home from the track.

I ran a 10.08 right off the trailer....at, get this, 141.08 mph. 1.62 short time. I still dunno if the lights were correct as I've never gone faster than 139.xx.

Next pass was a 10.71 @ 138.50. I had disconnected the MSD 2 step as that damn miss is back with it connected so I didn't have much boost on the line. (I do love the 2 step...it sure beats worrying about not enough or too much boost on the line).

Third pass was a 10.06 @ 139.21. This was with the boost turned up as far as it'll go. More on this later.

Fourth pass I tried tons of boost on the line, still without the 2 step being used, so I blew away the tires. 10.55 @ 138.12.

Final pass I hooked up the 2 step again....wanting the 2 step more than I didn't want the miss. (And sure enough, the miss returned.) I left the line at 3750 rpm which turned out to be the perfect launch rpm as I got a 1.56 60'. I had dialed a 10.15 and slept on the line for a poor reaction time but did manage to catch the guy and let off just a tad right at the top end. Broke out with a 10.135 at 133.86.

These last 3 passes were with the boost as high as it will go and 26 degrees of timing. EGT's on one run were 1896 (yep, no typo) and on the others ranged from 1740's to 1820's.)

Now about the boost. Some of you may remember I had bought a TE72 which turned out to have a 68mm compressor wheel in it instead of what I thought was a 72 mm wheel. I had it redone by John Craig into a 76-Q trim with a .96 exhaust housing. This turbo kicks ass but now I'm wondering if it ain't enough (or cynic that I am, perhaps it ain't got a 76mm wheel...lol) since I was only able to get to 24-25 lbs on the gauge. FAST records 21.x lbs. I know that when I compare the two before I start the engine, FAST will say -1.8 or -1.9, which I attribute to elevation. (I still can't figure where the other 2 lb discrepancy comes from though....and yes, I've switched map sensors and the same 2 lb difference is still there).

Anyhoo, discrepancy aside, I'm thinking about getting an 88/4 bolt. The Chance converter is back at the mfg...so I can have that made to what the bigger turbo would need.

I'd sure be interested in hearing from anyone who runs an 88...or even from those of you who have some thoughts on the pros and cons of this bigger turbo.

Thanks, Chris

 

[NastyGn]

Originally posted by ChrisCairns

I'd sure be interested in hearing from anyone who runs an 88...or even from those of you who have some thoughts on the pros and cons of this bigger turbo. Thanks, Chris

Hey Chris it looks like your flying. I have the 88 with a 3 bolt exhaust flange (the 4 bolt was not made yet when I bought it)
and like it very much. I talked to Harry once and he said I would not see enough difference going with the 4 bolt to make it worth changing it. The car has a 4800 stall converter. I am still working on the Speed Pro programing on the spool up at launch. At this time it spools slow up to about 5# but after that it comes up real fast. Infact so fast with just your foot it's hard to control a launch boost. That is why we installed a launch boost control (made by Conley's and I'm sure others) This is hooked up to my tranny button so when I push the button the low boost controller is working, when I let off the high boost side works.

So far the car has run 9.71 at 140.55 with a 13# launch and 18 ~ 19# of boost. The reason for the low boost launch is until I get the front end to stay down a little I'm scarred to take the back bumper off, and raising the high boost just keeps the front wheels up longer. My 60' are in the 1.33 to 1.40 range on 29.5 x 10.5 x 15 M/T (no W's)

Take Care

 

[S2V6RACER]

Chris, you need to focus more on the convertor for now. It seems that either of us know how to order them.

I believe you are only at 4 stickers as of now.



I am probably going with the 88 4 bolt with the stage motor, I'm talking to Bruce Aldred about it. He is setting up the stage motor in the car and handling some chassis mods this fall for the big time next year.

I still have a few shims and a pump gasket taped up in a box from Marty, that should fix it.

From what I can visualize on the boost controller, I ASSume you are basically forgetting about what psi you will be at at launch because essentially the wastegate won't let it get above a specified psi. I like that. You just watch RPM's? Once the tranny button is released it goes to your regular hi-psi wastegate. This seems to be a more and more discussed topic. I read that Conley has been working on this concept with his car and it is working.

I can see also working on a "delay" from low to hi-psi, this would perhaps let you work on your max 60' then pouring the boost on so you don't blow the tires loose.

Where's Chuck on this?

 

[NastyGn]

Originally posted by Ted A.
From what I can visualize on the boost controller, I ASSume you are basically forgetting about what psi you will be at at launch because essentially the wastegate won't let it get above a specified psi. I like that. You just watch RPM's? Once the tranny button is released it goes to your regular hi-psi wastegate. This seems to be a more and more discussed topic. I read that Conley has been working on this concept with his car and it is working.

I can see also working on a "delay" from low to hi-psi, this would perhaps let you work on your max 60' then pouring the boost on so you don't blow the tires loose.

Where's Chuck on this?

Well you set what boost you want to launch at, the lowest setting will be what ever your wastegate spring is, the rpm will be what your converter stalls at or flashes at. I have used this system for 2 years now and like it very much. I'm sure since this is in a electrical circut to install a delay timer would not be hard to do. I find I can set the launch boost to what ever the track will handle for a launch and after that (as low as it can go sometimes) I start making chassie adjustments.

I love these things

 

[ChrisCairns]

Neil....good info, just what I was looking for.

I was talking to another S2 guy (I won't mention his name, hopefully he'll read this and chime in) at BG and he told me to go watch the 88 people spool up. I did watch a few and sure enough, they seemed to take a long time to get to where they needed for launch...and since at my home track we leave from a .400 pro tree I really can't afford the extra time.

I'm wondering now what other options I have turbowise, without talking to a turbo salesman . I haven't heard any actual comparisons between bb and non-bb so I probably won't try a bb. Although I wonder if with my large (283 cu inch) motor if an 88 wouldn't spool as slow for me. Anyone wanna loan me one to try....lol.

I tried that type of boost controller you're using....I got the solenoid from Conley as a matter of fact....and I put a regulator into the launch boost line as I could never get the launch boost correct by just using the gate spring....even after buying another 2 of them. When I had the 68mm/72mm wheel problem I took it out of the equation and never did get around to putting it back on the car. Perhaps I should and junk the piece of crap MSD box. Although I think I'll try running larger wires to the box first...see if that cures the missing.

I wish I had your "can't keep the front end down" problem....lol.

Ted....hopefully I'll be able to join you as a 6 sticker man. For those of you wondering what this is about, Ted and I will both be reporting back on our Neil Chance converter story....but not just yet.

Chris

 

[re-evaluating]

MSD woes

Hey Chris
Sound like it is coming around. I just wanted to ad another thought on the MSD. I know we discussed this in another thread but I have had several other conversations regarding this problem. I have NOT personally had the missing at high rpm problem but seen it on Rays car. Are you running the new High output box or the standard unit? It was suggested I think by Harry to run a number 4 or 6 wire from the ground of the battery to the block. Apparently just using the frame as a ground can't provide enough difference in potential at that current level, copper is much better conductor (more free electrons). If you are considering running a larger conductor to the unit consider trying the large ground cable and let us know. I would love to know for sure if this will cure it once and for all. Anyway let us know Thanks Dave

 

[JoyOf6]

Chris,

Assuming a healthy combo, I happen to think it's odd you can only get 21# boost with the 76 as per FAST log. The discrepancy of the FAST/MAP sensor with a gauge is common, although yours is a bigger delta than normal (I see 2#). Regardless of that, I'd look for "mechanical" culprits in addition to the turbo. Header gasket leaks/burns, bad compression in a hole (i.e., tweaked exh. valves), etc. OTOH, 139 mph at that boost by itself doesn't suggest anything seriously wrong.

IMO, for racing Pro Tree brackets, consistent staging, launch boost/rpm, R/T, and of course deadly ET consistency are where it's at, unless you have a lot of ducks up there in the NW . Maybe TT is in your future. Yup, as Ted/Neal imply, gotta find the magic converter - your 60' is leaving a bunch sitting on the ET table.

Good to hear some race reports.

Art

 

[ChrisCairns]

Re: MSD woes

Dave....I uprgraded my positive cable from a 2-0 to a 0-0 a few months ago so I still have the 2-0. That's the one I'm going to use for the negative to the block. And I presently have the negative going to the frame...then to the engine via the mid plate. I never knew about the poor conductivity of the frame. Hopefully you're onto something. I'll let ya know.

And I wasn't even aware that there are different MSD boxes for our cars
. I'll look when I get home (having to work today).

Hey Art,

I agree. Doesn't make sense to me either about running out of turbo. I've looked for exhaust leaks, intake leaks....yesterday I removed the Racegate...the valve looks perfect although the cast seat needs a little work. Not much though but I'll get some valve lapping compound this week and smooth it out a bit.

Yesterday afternoon I was checking the plugs....and I found wet black carbon on the plug from #4. Looking into the bore with a flashlight I could see lots of wet black crap on the piston.

So you may be right on the money about something wrong with the hard parts of the engine. Dunno what yet....I'll do a compression or leakdown this week. And I probably won't remove the head until the season is over...although I may switch around 2 injectors to see if the wetness changes cylinders. Don't want to NOT be able to make Vegas.

And how's yours coming? Get that pesky air removed?
Chris

 

[JoyOf6]

Re: Re: MSD woes

Originally posted by ChrisCairns

I agree. Doesn't make sense to me either about running out of turbo. I've looked for exhaust leaks, intake leaks....yesterday I removed the Racegate...the valve looks perfect although the cast seat needs a little work. Not much though but I'll get some valve lapping compound this week and smooth it out a bit.

I've heard that situation stated before (low boost construed as running out of turbo). In my limited experience, I've always found a root problem when I couldn't achieve 30# at will, and it's almost never pretty. Our combos probably don't differ all that much except I have a converter that's taking care of business. At what rpm do you shift?


Yesterday afternoon I was checking the plugs....and I found wet black carbon on the plug from #4. Looking into the bore with a flashlight I could see lots of wet black crap on the piston.
So you may be right on the money about something wrong with the hard parts of the engine. [/QUOTE]

This idea is based partly on the Horror I've experienced with certain components over the past two years, which have obvious effects on boost. It's never, "Oh look, the bleeder valve is shut."


I'll do a compression or leakdown this week. [/QUOTE]

Let us know the results.


And how's yours coming? Get that pesky air removed?
Chris [/QUOTE]

Yes, I erred on the side of caution during the process, and now my chosen heir with have no air whilst airing it out. Waiting for turbo work now. In the meantime, I got the engine rebuilt in my other GN, changed some stuff, and it's screamin' for stickies.

Art

 

[ChrisCairns]

Re: Re: Re: MSD woes

Originally posted by JoyOf6


I've heard that situation stated before (low boost construed as running out of turbo). In my limited experience, I've always found a root problem when I couldn't achieve 30# at will, and it's almost never pretty. Our combos probably don't differ all that much except I have a converter that's taking care of business. At what rpm do you shift?

I just checked my log from last Saturday and I shifter at 6300 1st to 2nd, 6300 2nd to 3rd, and went through the traps at 6250.


Yesterday afternoon I was checking the plugs....and I found wet black carbon on the plug from #4. Looking into the bore with a flashlight I could see lots of wet black crap on the piston.
So you may be right on the money about something wrong with the hard parts of the engine.

This idea is based partly on the Horror I've experienced with certain components over the past two years, which have obvious effects on boost. It's never, "Oh look, the bleeder valve is shut."


I'll do a compression or leakdown this week. [/QUOTE]

Let us know the results.

Will do, and last night I looked at that plug again, along with peeking in the cylinder....everything is now dry. Must be my injector. ( I forgot to smell the plug the first time...probably would have been a clue....lol ) And to think I had the injectors cleaned and flowed this spring....to the tune of $96.00.



And how's yours coming? Get that pesky air removed?
Chris [/QUOTE]

Yes, I erred on the side of caution during the process, and now my chosen heir with have no air whilst airing it out. Waiting for turbo work now. In the meantime, I got the engine rebuilt in my other GN, changed some stuff, and it's screamin' for stickies.

Art [/QUOTE]

Thanks Art....And will we see you in Las Vegas???

 

[steve hughes]

Chris i have a few thouhts on your miss with the msd. You aren't running the hot wire off the alternator or running solid core plug wires are you? If this isn't the case you might want to shield the wires going to the msd. It might be picking up some kind of electrical noise. Just a thought.

 

[ChrisCairns]

Originally posted by steve hughes
Chris i have a few thouhts on your miss with the msd. You aren't running the hot wire off the alternator or running solid core plug wires are you? If this isn't the case you might want to shield the wires going to the msd. It might be picking up some kind of electrical noise. Just a thought.

Thanks Steve. The MSD hot wire is direct to the bat and the ground is off the frame. Bat ground direct to the frame but as we've discussed in above posts I'm going to run the bat ground direct to the engine to see if that'll fix it.

**************************************

I'm quoting John Estill following this...with his permission. He gives a definitive answer on whether or not I'm out of turbo. I've thanked John privately, now I thank you publicly John, for taking the time to run my numbers and come up with your conclusions.

----------------------------

Chris -

According to my calculations (for whatever that's worth), it looks like
you would be going off the edge of the compressor map at about 24 psi
boost at 6500 rpm. Even at 5000 rpm you are pretty close to the edge,
though still within the map. There is no way you could run 30 psi with
that T76, both for air flow reasons (your engine wants more air at 30
psi than that T76 can move) and for compression ratio reasons. Up at
the altitude you're at, the inlet pressure is so low that the
compression ratio (outlet pressure divided by inlet pressure) goes way
up, and at 30 psi the compression ratio is also off the map.

This is all assuming that your actual compressor matches the T76 map on
the turbonetics site. Now you probably *could* get it to make your
desired boost, as others have suggested, by blocking in your wastegate.
You could try that and see if you can even get to the boost level you
want that way. If you do, be aware that this will overspeed that
sucker! If I'm reading the compressor curves right, the highest rpm
they show is 95,300 rpm. It'll have to go a lot faster than that to get
you 30 psi, and I'd be worried about long term longevity if you run that
way. I will admit that it was pretty neat when Greg Krings turbine
wheel let go and punched 4 holes in his turbine housing and one hole in
his hood! Wish I could remember how big his engine is and what
turbo he was running at that time.

If you talk to a turbo salesman about an upgrade, make sure you tell
them about your altitude and how the local air pressure is about 26"
mercury or so. They need to take that into account. That by itself
means you can't get as much out of a T76 as people at lower elevations.

Hope that helps!

John Estill

 

[JoyOf6]

Chris,

Waddaya gonna do now?

Art

 

[S2V6RACER]

Chris, the next easiest thing for you to do is move instead of putting on a bigger turbo.

You should e-mail Dave Bamford and ask him if he has resolved his issues with the DIS-4. I know he was talking about going through 2 boxes and finally unhooking it at Norwalk this year.

 

[TurboTR]

Spray it

Yeah it's kinda funny to see "hardened against EMI" as a feature, then one paragraph down saying you CAN'T run solid core wires- too much EMI

Kinda like when Windoze says "this program can't be closed by Windoze. What do you want to do? Close anyway?" LOL

TurboTR

 

[ChrisCairns]

Originally posted by JoyOf6
Chris,

Waddaya gonna do now?

Art

The never ending process of upgrading.

The lag of the 88 scares me....and the small increase of an 80 worries me that it ain't enough.

Anyone got any suggestions? Hey, suggestions for someone else are great to make....they're cheap.

 

[JDEstill]

I just wanna say, I hope no one thinks I'm getting too big fer my britches here! I recognize that I'm not a go fast guy like so many others here, I haven't Done It myself, but I do like to talk about it. I'm just a poor ole engineer that thinks he knows how to calculate stuff. So, that being said, I'd talk to one of the vendors before taking my calcs as gospel. On the other hand, I think I'm right, and if I didn't think so I wouldn't say anything at all. I really try not to speak up unless I'm pretty sure of what I'm saying. Just wanting to get that out there, so you know where I'm coming from, and you know how much weight to put behind what I wrote. I don't want to fool anybody into thinking I'm some super expert here.

John Estill

 

[ChrisCairns]

Originally posted by Ted A.
Chris, the next easiest thing for you to do is move instead of putting on a bigger turbo.

You should e-mail Dave Bamford and ask him if he has resolved his issues with the DIS-4. I know he was talking about going through 2 boxes and finally unhooking it at Norwalk this year.

I just finished putting the other large ground wire direct from the bat to the engine. Oh, btw, that wire was a 2-0, not a 1-0 as I previously stated. And now I know why they have side posts and top posts on the batteries. I'll probably end up using them all.

I'm now wondering about the hot wire directly from the MSD box to the bat. I've run a 10 gauge....I wonder if it's big enough.

Think I'll take your advice Ted and email Dave...see what wire he runs. Do you happen to have his email or is he on this board?

Thanks, Chris

 

[ChrisCairns]

Originally posted by JDEstill
I just wanna say, I hope no one thinks I'm getting too big fer my britches here! I recognize that I'm not a go fast guy like so many others here, I haven't Done It myself, but I do like to talk about it. I'm just a poor ole engineer that thinks he knows how to calculate stuff. So, that being said, I'd talk to one of the vendors before taking my calcs as gospel. On the other hand, I think I'm right, and if I didn't think so I wouldn't say anything at all. I really try not to speak up unless I'm pretty sure of what I'm saying. Just wanting to get that out there, so you know where I'm coming from, and you know how much weight to put behind what I wrote. I don't want to fool anybody into thinking I'm some super expert here.

John Estill

I think I speak for a lot of people when I say you're one of the "good guys." One of those that use science and not rumor, hearsay or bullschit.

I for one, always appreciate, and listen to, whatever you say.

Hopefully you'll keep offering your expertise to those of us who are extremely good looking yet somewhat dumb.

Chris

 

[9SECVSIX]

LT 76-Q Trim.

Chris, I'll give you my experience with the JC. LT76-Q trim (4 bolt-on center-.81)
My motor is a 276" -9:1 Champion Al heads, 236-solid roller, 1:65 T&D's. Ported BGC Intake with 70mm TB and a Mark brown liquid intercooler. ATR-4 bolt headers and a fender well dump!
With sea level air and the bleeder valve bye passed , equal pressure to both sides of the Racegate, and
the spring adjusted in all the way the turbo would cross the 1/4 at 24psi, I went over the header system with a fine tooth comb and found no leaks. The car is 3400lbs with driver and at 145MPH this figures out to 800HP. IMHO that's all there is from that turbo at sea level on my combo. I was running 26deg and 11.2-11.5 Air fuel. John suggested I try a Tang housing for more MPH but I didn't bother, when I find a new crank maybe I'll try a 88, the home works already done, it's a kick ass turbo bye all means.
Later
Brent