Can't make boost on the brakes.

[Big_P]

Yarr. Can't seem to make power while brake boosting at the line.

I need to put the mods in my sig so I don't have to keep typing them up, heh.

85 600SE Conv't
89 a413 w/ custom converter (stock stall but made to fit 85 engine to 89 trans)
wicked ported head, stock valves
t3/t4 hybrid
wicked ported exhaust manifold
stock intake manifold
stock exhaust ( :sick: I know, I know, getting there)
TII I/C
87 electronics (I am using a bathtub head though), custom cal, 3 bar map, +40's, 12deg base timing.

If I stand on the gas and the brake for 10 full seconds I might be able to make 4psi, enough to bark the tires which are total garbage and need to be replaced. I'm paranoid about brake boosting that long, that's how I sent the spider gears through the case of my 85 trans :thumb:

but when boost hits, watch the F out! I have a MBC set to 12psi and hot diggety damn, this thing can boogie.

[Big_P]

help :(

Cam timing and ignition timing are dead on.

[bakes]

cal limiting it???
so you have anti lag turned on?
what cal are you running?
unplug the waste gate and try to boost it (only for testing ) watch you boost level!!

[turbovanman²]

Any intake leaks? What size turbo? T3/T4 doesn't tell a whole lot, :o What stall on the converter? Its possible they messed it up, had that happen to me once, :(

I would drop the DP and see what happens, if still the same, try a proper cal.

[BLUEBALL]

x2 on incorrect stall if all else is in order. Unfortunately thats not what ya wanna hear,but it happens..:o

[contraption22]

What they said. What is the flash stall of the converter (what rpm does the engine shoot to when you first floor it)

What are the specific turbo specs?

[GLHNSLHT2]

stock suckthrough intake???

[Big_P]

Okay, it stalls at a hair above 2000, according to my digital tachometer of questionable accountability. If I hold the gas and the brake together, car not moving, for a while I can get it to 2500RPM.

Timing is at dead-nuts 12*. Cam and crank timing are dead-nuts too.

I talked to the guy who built the head/turbo. It's a stock T3 with a Stage 3 exhaust wheel in the stock .48 housing. On the compressor side is a 50 trim T4 wheel. It was ported to fit all that in there. Looks pretty neat. The kid before me who had this setup said it made ridiculous power at the low end. Wheel spin problems merging into traffic, etc. Granted he had an a555 to back it up.

I dropped the exhaust down and still can't build boost.

I have a manual boost controller so it's not the computer restricting the boost.

I also can't build more than a few lbs of boost before 3700RPM. I'm assuming these problems are related. Next thing I'm going to check is the wastegate staying open a little bit?

[bakes]

Is the waste gate puck sealing the hole? I say this because i had a s60 that the puck snapped off and it acted like this.

[Force Fed Mopar]

I dunno, sounds normal for a turbo of those specs. My .48 S70 w/ a clipped stock wheel won't spool till nearly 3000 rpm.

[contraption22]

Okay, it stalls at a hair above 2000, according to my digital tachometer of questionable accountability. If I hold the gas and the brake together, car not moving, for a while I can get it to 2500RPM.

Timing is at dead-nuts 12*. Cam and crank timing are dead-nuts too.

I talked to the guy who built the head/turbo. It's a stock T3 with a Stage 3 exhaust wheel in the stock .48 housing. On the compressor side is a 50 trim T4 wheel. It was ported to fit all that in there. Looks pretty neat. The kid before me who had this setup said it made ridiculous power at the low end. Wheel spin problems merging into traffic, etc. Granted he had an a555 to back it up.



From my experience, that is an absoltely horrible turbo combination, and the way you describe it is exactly how I would expect it to act.

[turbovanman²]

That should spool fairly well. If your driving along, say doing 40 mph and go WOT, what does it do?

Based on your info, I'd say the converter is bad, sounds like mine when they get it wrong, :(

[unluckyty]

When I tried to run a ,t3/t4 stage 1 exhaust .63, with an auto/stock converter, fwd stage 5, had the same problem.
I tried adjusting timing,fuel, went back to stock LM, still took forever to build boost at the line. I have a video of it some where, sounded like a jet trying to take off. If I remember, it ran 14.0@99 mph, with the a555 would do 12.9's@ 105/6 all day long.
Especially with the stage 3 wheel, your fighting an uphill battle. I think the stock Garrett and the a413 is a good combo.
I'm running a413/stock garrett in my SL now. Can spool it at will on the line. Has run a 14.20's on street tires, and I haven't thrown alot of boost at it yet.

Greg

[turbovanman²]

I've spooled a stage III wheel on the van with no problems, sure I didn't hit full boost until 4200 but I could easily build boost off the line.

[jory]

time for a 5 speed! I got everything you need if you want to do that :D

[GLHNSLHT2]

What intake manifold?!?!

[Big_P]

Stock intake. Yeah yeah, next winter's project.

Anyway, I swapped wastegates to see if that was the problem, because the one in it either has a REALLY stiff spring or it's sticky. But it didn't make a difference. So I went back to the old one. (Pain in the --- to do! Never want to do that again).

Either way, I called Norm, the guy who built the head/turbo, and he told me to plumb the boost controller into the nipple on the turbo. I did that, and now it doesnt boost creep like it did before and holds boost when it shifts gears. I'm getting there!


Now, I put in a new Autometer boost/vac gauge to replace the old junk quality one. I'm pulling 16" of vac at idle.

This car has a roller cam but a square tooth sprocket for the 85 motor. The previous owner does not remember what year the roller cam is, so it could have originally had a round tooth sprocket, which would mean the cam timing would be 4 degrees off. Could 4 degrees off timing cause something like this? How would I know if the cam is the correct one?

[turbovanman²]

Cam timing can affect spool for sure, 4 deg's can make a huge difference. The only way your going to know is to actually centerline the cam.

[GLHNSLHT2]

Stock intake. Yeah yeah, next winter's project.

Anyway, I swapped wastegates to see if that was the problem, because the one in it either has a REALLY stiff spring or it's sticky. But it didn't make a difference. So I went back to the old one. (Pain in the --- to do! Never want to do that again).

Either way, I called Norm, the guy who built the head/turbo, and he told me to plumb the boost controller into the nipple on the turbo. I did that, and now it doesnt boost creep like it did before and holds boost when it shifts gears. I'm getting there!


Now, I put in a new Autometer boost/vac gauge to replace the old junk quality one. I'm pulling 16" of vac at idle.

This car has a roller cam but a square tooth sprocket for the 85 motor. The previous owner does not remember what year the roller cam is, so it could have originally had a round tooth sprocket, which would mean the cam timing would be 4 degrees off. Could 4 degrees off timing cause something like this? How would I know if the cam is the correct one?


So since you've said "stock intake" twice which really doesn't say what intake you're running that's "stock" I'm going to assume it's a stock suckthrough setup? And you wonder why it doesn't make boost? Really? Like trying to suck air through one of those tiny coffee straws. My S60 turbo likes 3" intake plumbing. And your T3/T4 is being fed with what? A 1.6" hole? LOL And you really wonder why you can't make boost on the brakes?????? Maybe because everything downstream is outflowing what you're putting into it? Think of it like a river with a dam. If the restriction/DAM is before the turbo and the river after the dam flows more than the dam lets through what happens? If the dam can outflow the lower river then you get "boost" in the lower river. Otherwise you'll never get boost. Also having the dam before the turbo makes the turbo work that much harder to create boost so it puts you on a different part of the map and not in a good way.

[Big_P]

So since you've said "stock intake" twice which really doesn't say what intake you're running that's "stock" I'm going to assume it's a stock suckthrough setup? And you wonder why it doesn't make boost? Really? Like trying to suck air through one of those tiny coffee straws. My S60 turbo likes 3" intake plumbing. And your T3/T4 is being fed with what? A 1.6" hole? LOL And you really wonder why you can't make boost on the brakes?????? Maybe because everything downstream is outflowing what you're putting into it? Think of it like a river with a dam. If the restriction/DAM is before the turbo and the river after the dam flows more than the dam lets through what happens? If the dam can outflow the lower river then you get "boost" in the lower river. Otherwise you'll never get boost. Also having the dam before the turbo makes the turbo work that much harder to create boost so it puts you on a different part of the map and not in a good way.

The reason I'm posting this is because this setup (he had a S60 cam and 3" exhaust both of which I do not have) was used on Nick Perry's Shadow which was an absolute rocket ship. Same stock 1-piece TI intake, too.

[Big_P]

Cam timing can affect spool for sure, 4 deg's can make a huge difference. The only way your going to know is to actually centerline the cam.

How would I go about doing that? Degree wheel?

[Dave]

How would I go about doing that? Degree wheel?

Degreeing Wheel

http://www.summitracing.com/parts/SUM-G1057/

There's a lot of tutorials on degreeing your cam. Honestly get the right cam or cam gear on there and set up your timing the correct way and call it a day. I wasnt aware the square tooth vs round tooth had different timing marks.

I too had the same problem with the Spirit. Ended up being the torque converter sprag was shot.

[turbovanman²]

How would I go about doing that? Degree wheel?

Degree wheel, cam specs and a dial indictator.

[Big_P]

aaaaaaaaaaaaand I spun a bearing today racing a Jaguar.

[Dave]

aaaaaaaaaaaaand I spun a bearing today racing a Jaguar.

F*ck it. Did you win? ;) Pics for carnage please!

[GLHNSLHT2]

The reason I'm posting this is because this setup (he had a S60 cam and 3" exhaust both of which I do not have) was used on Nick Perry's Shadow which was an absolute rocket ship. Same stock 1-piece TI intake, too.


See now we can get on with things. It's not a "stock intake" for your car. That's why you need to clarify. It is stock but better than a stock suckthrough intake. needed to clarify what stock intake you are running.

[Dave]

See now we can get on with things. It's not a "stock intake" for your car. That's why you need to clarify. It is stock but better than a stock suckthrough intake. needed to clarify what stock intake you are running.

"Sir, what size wheels are you looking for?" "I dunno.... stock!"

[bfarroo]

Converter sounds a little tight, I've always been able to get my stock converters up around 3000 on the brakes, I've only had a stock turbo but can easily get 10# on the brakes.

[drunk on diesel]

sounds like you need a looser converter or a 2-step... aka bang-bang