New great Dyno #'s but a problem

[DR. EVIL]

Finally got the beast all together and on the machine to check out some numbers and see how the air/fuel was treating me.

I have to say the Trans+ was a worthy investment. I was able I to keep a very stable 12.3-12.4 A/F ratio with it.

Cranked the boost up to about 20ish
got 384RWHP, and 397ft/lbs.... no propain yet added in.

the funny thing is, that was at a measly 5100rpm, it seemed to hit a brick wall at close to 5200rpms, like a rev-limiter, we weren't sure because we shut it down when it happened a couple times in a row. Always at the same place in the Rpm range.

Does the chip that came with the Trans+ have a limiter on it? I haven't updated the chip since we did the new 212/212 comp cam, JE forged pistons, bored it out about 20 over and refreshed the rest of the motor.

I know it wasn't leaning out, I can't tell ya O2s because I haven't hooked up the other program up to the motor yet.


we know its got at least 400rwhp in it on pump gas, but if I can't rap out the motor, I won't really know for sure.

 

[pacecarta]

shouldnt hit revlimiter at 5000-5200

heres the specs for the limiter on the extender

Idle / RevLimit
A - 750/6000 Stock cam
B - 800/6000 200 – 208 cam
C - 850/6200 210 – 218 cam
D - 900/6300 Big cam
E - 1000/6300 Big cam
F - 850/none 200 – 208 cam
G - 900/none 210 – 218 cam
H - 1000/none Big cam
X - Custom

 

[turbosam6]

Valve springs?

 

[wiked87gn]

make sure the third switch on the T plus is set to off.. on it sets a limiter for the MAF hence the booging if not then is valve springs..

 

[DR. EVIL]

I got the springs with the kit together from the cam from Comp
if they are the wrong springs, they shipped the wrong ones, or they were overtorqued

I had only been driving the car for about a week (stock 15psi, and 17 adv timing) and it pushed out a head gasket.... so we replaced it a couple days ago.... thats when we dynoed the car and got those numbers.

Today, after having it only 1 day, the head gasket seems to have pushed again!! I know for a FACT it wasn't leaning out and the boost wasn't over 17psi. I never even ran the car to red line or pushed it past 70mph

I had gunned it some, just in 1 gear up to about 45mph and then started seeing some whitish smoke.... so I rolled it to a stop to have it towed

I looked at the motor afterwards, doesn't appear to be any leaking around the heads, but the overflow for the coolant had literally overflowed and there was some coolant on my battery.

 

[azgn]

running 12.3-4 AF ratio is blowup territory on turbo cars.....try 11.5 max or so and you'll keep your headgaskets

 

[wiked87gn]

agreed..

Originally posted by azgn
running 12.3-4 AF ratio is blowup territory on turbo cars.....try 11.5 max or so and you'll keep your headgaskets

 

[2 SLOW]

I also agree that the AF ratio needs to be about a point lower (richer). But also to go 45 mph in first gear you would be going well over 6000 rpm. Even at 36 mph my tranny is shifting at about 5600 rpm. Sounds like you blew the headgasket, sucked water in the cylinder that made steam giving you the white smoke, and then pushed air in the radiator and out the overflow.

I'd say you may have done more than just blow a headgasket, or maybe not. You might want to check valve train and bearings when you take it apart. Holding it in first gear at WOT makes it to easy to over rev it. With a modified car at the drag strip you are usually in second gear well before the 60 ft mark. That comes up fast. Most people I know don't manually shift first to second.

Hope your problem is limited to a headgasket. Good luck.

 

[DR. EVIL]

well, thats quite interesting info indeed, guess I shouldn't have gone with the "tuner's" idea of good ratio,

well I'm definately not paying for this Headgasket replacement....

I barely had gotten into it luckily, and definately didn't even give it gas after the smoke appeared. I was in second gear at 45mph. I know for a fact its not reving past 5150rpms, even when it was floored in 3rd on the dyno before. I'm just so mad that he charged me $400 to fix the gasket the first time, then I helped him tune it to what he said was safe and BOOM next day dead in the water again.

so far we have possibly bad or mis-installed valve springs and a far too lean condition for the motor right?

 

[DR. EVIL]

ttt

 

[GNVYUS 1]

12.3 is not lean or even close to far to lean. That air/fuel ratio is not going to cause a head gasket failure alone, detonation will though at any air/fuel ratio with enough cylinder pressure.

It sounds like you ran 20psi on pump gas. There's your problem if you are not running alky or at least 100 octane at that psi level.

Did any knock show up during the dyno run?

 

[salvageV6]

I agree with Dr. Booster, I've run over 12.0 on the dyno with no issues.

Pump gas and alky.

The ratio itself wouldn't be the problem but the octane level would be questionable for 20psi.

I also agree the increased load on the street or the track could be an issue at 12.3-12.4 and 11.5 is the usual safe A/F ratio for racing.

What heads and valve train are on the car?

If the gaskets have pushed before I would suspect a problem in the design/installation of the combo. rather than the suggested A/F ratio.

Especially with the brick wall at 5200 scenario.

 

[marleyskater420]

Originally posted by DR.BOOSTER
12.3 is not lean or even close to far to lean. That air/fuel ratio is not going to cause a head gasket failure alone, detonation will though at any air/fuel ratio with enough cylinder pressure.

It sounds like you ran 20psi on pump gas. There's your problem if you are not running alky or at least 100 octane at that psi level.

Did any knock show up during the dyno run?

20psi on pump gas is death indeed.

What octane were you running?

Im curious to know because I have a similar setup except with a 63mm turbo and no trans+, and I have 50lber's w/ alky and a FMIC.

If you hit those numbers on 20psi I really wonder what I can hit.

 

[DR. EVIL]

the 20psi was just on a dyno run once in 3rd on 93 octane. However when the gasket blew, I was down to stock 15psi on the road before we ever dynoed it. The second time it blew when I just got it back it was still about 16psi on the road doing about 45mph.

I have propane injection all set up, but its not filled and running yet.

The only things not stock on that motor's internals, are the JE pistons, bored .20 over, the 212/212 comp cam, and everything else is just refreshed with new gaskets and rods everything.

the combo was straight from Comp together as a kit, the cam, timing chain, and valve springs deal

Heads are still stock for now.

he didn't seem to think the springs caused that brick wall at 5200, saying didn't torque them wrong and they were sent with the cam kit

 

[marleyskater420]

Originally posted by DR. EVIL
the 20psi was just on a dyno run once in 3rd on 93 octane. However when the gasket blew, I was down to stock 15psi on the road before we ever dynoed it. The second time it blew when I just got it back it was still about 16psi on the road doing about 45mph.

I have propane injection all set up, but its not filled and running yet.

The only things not stock on that motor's internals, are the JE pistons, bored .20 over, the 212/212 comp cam, and everything else is just refreshed with new gaskets and rods everything.

the combo was straight from Comp together as a kit, the cam, timing chain, and valve springs deal

Heads are still stock for now.

he didn't seem to think the springs caused that brick wall at 5200, saying didn't torque them wrong and they were sent with the cam kit

So what exactly is your setup?

I have a TE-45
50lbers
HW340
Razors alky
Dutt FMIC
THDP w/ dump pipe(open exhaust)
PTS street/strip tranny w/ billet planetary,pump, and bottom feed.
9x11 3200 l/u
I need to install my LT1 valvesprings
Eric marshall alky chip
bored out stock TB

Do you think Ill be anywhere near what you are at?

 

[gn4u2c]

sounds like your just to boost happy with a stock intercooler thats heating up fast and helping with detination. From what I understand even a short blast into knock is enough to weaken the gasket and then it can blow at any time. I would try keeping the boost down under 15 psi with the new head gasket if thats all thats wrong for a week or 2 see what happens.

 

[DR. EVIL]

Originally posted by marleyskater420
So what exactly is your setup?

Its in my sig

Originally posted by gn4u2c
sounds like your just to boost happy with a stock intercooler thats heating up fast and helping with detination. From what I understand even a short blast into knock is enough to weaken the gasket and then it can blow at any time. I would try keeping the boost down under 15 psi with the new head gasket if thats all thats wrong for a week or 2 see what happens.

Very possible, but its prolly a combination of the new internals and that boost, because I used to run close to 20psi for almost 2 years with no problems before the internals and never a blown gasket til now

 

[GNVYUS 1]

Whats the new motors compression?

I would assume that when you had your motor built they milled the heads
Did they ever remill the heads after the blown HG?

If you are in the 8:5:1 ratio or more your pretty much starting over on your tune and what the new motor knocks at.

What about WOT timing?

 

[Army MP]

Just my 2 cents, sounds like ya gotta bad MAF. For the stuttering.

 

[DR. EVIL]

I'll have to ask exactly what all internal work was done on the heads and such. Watched him clean off the head after the first gasket went. The compression is stock, we didn't get higher pistons, just forged now

I have an LT1 3" maf, the trans+ seemed to be working quite well at least

the WOT timing is still 17 advanced like the base timing is. We didn't really mess with timing for the most part.