LOW DYNO #S (3.3SS EFI/PMO ITBS EURO HEADERS M&K muffler

[Spenny_b]

If you're using VAG CoP's (as suggested above), were they bought new? I remember that VAG had real problems a number of years ago with coils failing all over the place. If you happen to have bought some 2nd hand old-vintage units, then they could be breaking down under load.

Are all the important areas of your engine harness adequately screened and twisted to reject as much electrical noise as possible? Are all harness earth points good? (no, everyone says "yes", but are they really...?)

[Techno Duck]

Originally Posted by Spenny_b

I'll throw one in there as well....make sure the vacuum hose to the fuel pressure regulator is hooked up (to your manifold, below one of the throttle butterflies I'm guessing with an ITB setup?); if it isn't you're going to be running out of fuel pressure with increased engine speed.

I think if the vacuum source was not hooked up you would just get your base fuel pressure at all times. You would only run out of fuel pressure if this was a boosted car (rising rate fuel pressure). If no line was hooked up, it would probably be rich under most running conditions, especially idle.

Disclaimer: I know enough about tuning to blow up an engine, so i could be wrong

[Tippy]

Originally Posted by Techno Duck

I think if the vacuum source was not hooked up you would just get your base fuel pressure at all times. You would only run out of fuel pressure if this was a boosted car (rising rate fuel pressure). If no line was hooked up, it would probably be rich under most running conditions, especially idle.

Disclaimer: I know enough about tuning to blow up an engine, so i could be wrong

That sounds right. How much richer depends on cam size and injector size.

Larger, long duration cams have low vacuum, so not a lot of change from idle to full load. Bigger injectors should put out more fuel per PSI than smaller.

[al lkosmal]

ok nippy.....plenty of response to your dismal dyno numbers....how about responding to a few of the questions being asked or a follow up? Have you investigated any of the potential causes?

[Tippy]

Originally Posted by al lkosmal

ok nippy.....plenty of response to your dismal dyno numbers....how about responding to a few of the questions being asked or a follow up? Have you investigated any of the potential causes?

Isn't it funny how the most interesting threads started are by those who never respond back?!

[nippy]

Sorry guys been working on it. We noticed the engine had a small miss at idle. I luckily met some good ol boys that wrench on Rolex 24 teams over the weekend. The car is going to their shop to be diagnosed and looked at in an about an hour.They also did a quick check for leaks at the manifolds to the block and all was good. They were also saying the dyna packs aren't the greatest dyno, not sure about that.

They found all these hoses going to the ITBs had crimps on them but were not crimped. As soon as we even wiggled the hoses you could here the RPM go up at idle.


They had this car sitting there being worked on so I figured they were probably qualified to work on my lil engine (yes that's real). That's a full carbon GT3R behind it.

[nippy]

Got the results of the compession test back. We found the spark plus were not torqued down at all. Right side bank running rich, plugs were black. The throttle cable its only functioning at about 85% full capacity from pedal to ITBs. Wiring harness from ecu to engine was not secured in any way, basically just hanging there and free to move about, the spade connection on the tachometer had bad crimp and was literally hanging there. Mostly install issues and small corrections. So we will get the car to Daytona for the Rolex 24 and when we get back we will go all through the car and wiring.

My guys believe the dyno is way wrong. They drove it and said its at least 220HP. They want to get all loose ends tied up and get a new tune and re dyno. I took it to a race shop. They seemed to be real good. Had a few nice toys laying around. They are supporting a car in the Continental tire series this weekend at Daytona. They assured me the engine is healthy.


Compression test results were
1 165
2 165
3 172
4 180
5 176
6 182

The shop

[safe]

Originally Posted by nippy

Got the results of the compession test back. We found the spark plus were not torqued down at all. Right side bank running rich, plugs were black. The throttle cable its only functioning at about 85% full capacity from pedal to ITBs. Wiring harness from ecu to engine was not secured in any way, basically just hanging there and free to move about, the spade connection on the tachometer had bad crimp and was literally hanging there. Mostly install issues and small corrections. So we will get the car to Daytona for the Rolex 24 and when we get back we will go all through the car and wiring.

My guys believe the dyno is way wrong. They drove it and said its at least 220HP. They want to get all loose ends tied up and get a new tune and re dyno. I took it to a race shop. They seemed to be real good. Had a few nice toys laying around. They are supporting a car in the Continental tire series this weekend at Daytona. They assured me the engine is healthy.


Compression test results were
1 165
2 165
3 172
4 180
5 176
6 182

220 hp would still be a joke, if at the crank. This engine needs to be well above 260@crank.

Compression seems a bit uneven, but if its recently rebuilt it might not be properly broken in yet. Get out and drive it like you stole it when sorted out.

But good that you have gotten it to some competent guys that perhaps can troubleshoot issues instead of just blaming someone else.
A tuner that can only work a laptop is pretty useless.

[nippy]

I agree and they think its all in the tune once we get all the BS taken care of. I imagine opening up full throttle should help a bit to. .85 cents on the dollar is no Bueno...

[jpnovak]

While the items found are telling about overall build quality I don't think they would be the cause of your massive drop in torque on the dyno. Keep looking.

[al lkosmal]

Originally Posted by jpnovak

while the items found are telling about overall build quality i don't think they would be the cause of your massive drop in torque on the dyno. Keep looking.

+1

[nippy]

Not being rude but maybe you missed the part where we think there is a faulty dyno? Several guys in the know have driven the car and stated there's no way its only making 150HP. Also the drop off shown on the dyno is not felt at all. Jeff Gamroth from Rothsport and my guys at the local race shop all said they have never seen a dyno sheet like that. The guys at the local race shop drove the car to redline. So were thinking the tuner and his dyno are off.

[mepstein]

Great looking car.

[Tippy]

Hot damn, that car is beautiful!!!

GLW fix. 85% throttle should have been caught early on by the tuner. Most shops use a checklist of these things.

If you don't have every box checked off, they won't dyno.

[trond]

what exhaust is that, looks like 1.5"

[Tippy]

Originally Posted by trond

what exhaust is that, looks like 1.5"

Looks 1 5/8" to me?

[KNIGHTRACE]

I would be glad to help if you would like to call me, my number is 615.969.4917 I have done about 30 motors with the mod S cam 120/104 webcam... I have had a dozen or more 3.0 with big port 3.0 heads and larger intake valve motors that make 272 at the rear wheels on average. wheel weights and alignment also have an effect on these numbers.. a 3.3 by the way I am one of the few that do not like short stroke motors but if it is a single plug 3.3 with not very good head work 38.5mm 3.0 heads not the late 3.0 34mm port it should make 280 hp at 9.8:1 in my opinion.. 615.969.4917, William Knight
If all is correct or you believe so, I would take the pulley off the front of the motor and change it good chance it is timing problem

[MoreGAS]

Nippy
It may be a great idea to find a local Dynojet (which are widely found)and do 2-3 runs w Lambda being logged to check out whether you have real problems or not. That power fell off dramatically 2 X to 6K RPM and in an amount one would absolutely feel it quit pulling. The motor should be happy to run to 7K w that cam having lost only a small bit of HP from peak and be 250-260 at the wheels conservatively.
All the little things you have discovered would not result in this kind of power swings.

Kevin

[nippy]

Originally Posted by KNIGHTRACE

I would be glad to help if you would like to call me, my number is 615.969.4917 I have done about 30 motors with the mod S cam 120/104 webcam... I have had a dozen or more 3.0 with big port 3.0 heads and larger intake valve motors that make 272 at the rear wheels on average. wheel weights and alignment also have an effect on these numbers.. a 3.3 by the way I am one of the few that do not like short stroke motors but if it is a single plug 3.3 with not very good head work 38.5mm 3.0 heads not the late 3.0 34mm port it should make 280 hp at 9.8:1 in my opinion.. 615.969.4917, William Knight
If all is correct or you believe so, I would take the pulley off the front of the motor and change it good chance it is timing problem

Thanks will call you next week after Rolex, cheers.

[nippy]

Originally Posted by MoreGAS

Nippy
It may be a great idea to find a local Dynojet (which are widely found)and do 2-3 runs w Lambda being logged to check out whether you have real problems or not. That power fell off dramatically 2 X to 6K RPM and in an amount one would absolutely feel it quit pulling. The motor should be happy to run to 7K w that cam having lost only a small bit of HP from peak and be 250-260 at the wheels conservatively.
All the little things you have discovered would not result in this kind of power swings.

Kevin

were doing just that after we tie up the loose ends. Everybody is thinking the dyna paks were just off. The car feels good and pulls well up to red line but could use a little fine tuning. I think I just freaked out at such low numbers but now it's starting to look like the dyna machine/tuner were faulty along with a few previous mistakes with the itb and efi install.