Disappointing Dyno Run

[geargrinder427]

Hi,

I'm new to the Turbo Buicks and have been busy trying to get my GNX clone up to snuff. I just had it at the dyno shop today and it appears to have two issues . One is the spark is cutting out at 4700rpm and up. Second, the guy at the dyno shop said it appears the tranny or converter is slipping so I'm not getting power to the rear wheels like it should: . The car has a single disk vigilante 3500 stall with a metric 200 with the hardened parts put in back in 2005 from the paperwork that I got with the car. It has a rebuilt pump in the tranny as well.

The car appears to have a stock GM coil pack and autolight 8mm plug wires with NGK plugs.

I have attached the dyno results with alkycontrol on, gain set at 2-1/2 running methanol, and a pull with it off boost turned down. Both pulls were done in 3rd gear.

The car has a Turbo Tweaks chip but there are no timing set marks on it that I can see, I did not pull it out. Car is running a pt-67 turbo with 60lb injectors and 100lb valve springs. The car has the large 4" inlets and a large intercooler up front. This motor should make more than 300hp......

The MAP translator is a 3.5" with the switches set to on-on-off-off with 10% rich selected.

I am would greatly appreciate any suggestions on coil pack replacement or does it need a new chip ? Does the Tweaks chip control a rev limit or is this controlled somewhere else?

The dyno shop guy told me that the single disk vigilantes are not that good....Any one else had issues with them ? Any ideas on what converter I should be running and transmission suggestions ? I would be happy to have this car run low 11 on the street or basically launch like I see so many of them do well.......

Thanks for reading and your suggestions.

Andrew

 

[salvageV6]

I don't have any problem getting over 400 RWHP through my Vigilante single disk convert and the 2004R transmission.

I'd look at the converter and tranny as a combo. for sure.

Obviously after you fix the spark issue.

A coil pack swap is an easy test.

The Caspers $100 spark tester also works well if you can find someone in the area that has one that should pinpoint the problem easier.

 

[GNVYUS 1]

Coil packs should be swapped at 50k, they are super cheap as the guy on this board sells them for dirt.

Your car is building boost really slow, it came all in at 5200 rpm, way too late.

You didn't post any Scanmaster or Powerlogger data, that might help see what else is going on.

Looks like the alky is really fattening things up and then leaning out so you might want to tweak the that.

Any converter can start to go south on you, other than the drag strip, I'm not sure how you'll really find out if you're slipping accurately or not.

A 67 turbo at 22psi should make madd power so there is a ton left on the plate here. Timing can be found by the Scanmaster at WOT.

 

[Dave H]

Did anyone else noticed how much quicker boost builds without the alky? It hits 19-20 psi almost immediatly, where as with alky, it was at almost 4800 before it hit that much boost.

Did anything else change between runs except turning the alky off?

 

[wickedtt]

Hi,

I'm new to the Turbo Buicks and have been busy trying to get my GNX clone up to snuff. I just had it at the dyno shop today and it appears to have two issues . One is the spark is cutting out at 4700rpm and up. Second, the guy at the dyno shop said it appears the tranny or converter is slipping so I'm not getting power to the rear wheels like it should: . The car has a single disk vigilante 3500 stall with a metric 200 with the hardened parts put in back in 2005 from the paperwork that I got with the car. It has a rebuilt pump in the tranny as well.

The car appears to have a stock GM coil pack and autolight 8mm plug wires with NGK plugs.

I have attached the dyno results with alkycontrol on, gain set at 2-1/2 running methanol, and a pull with it off boost turned down. Both pulls were done in 3rd gear.

The car has a Turbo Tweaks chip but there are no timing set marks on it that I can see, I did not pull it out. Car is running a pt-67 turbo with 60lb injectors and 100lb valve springs. The car has the large 4" inlets and a large intercooler up front. This motor should make more than 300hp......

The MAP translator is a 3.5" with the switches set to on-on-off-off with 10% rich selected.

I am would greatly appreciate any suggestions on coil pack replacement or does it need a new chip ? Does the Tweaks chip control a rev limit or is this controlled somewhere else?

The dyno shop guy told me that the single disk vigilantes are not that good....Any one else had issues with them ? Any ideas on what converter I should be running and transmission suggestions ? I would be happy to have this car run low 11 on the street or basically launch like I see so many of them do well.......

Thanks for reading and your suggestions.

Andrew

List the mods you have??the vig what pump # is it or where you just told its a 3500 stall??

 

[Chuck Leeper]

Hmmnn..
w/alky: 246/248@ 5200.. power was still going up??[2.61 sec pull]
w/o alky 279/367@ 4000, and headed to the toilet as rpm climbs?? [4.92 secs to 5200, w/ a better AFR than the first pull]
I'd suspect something other than the ign to cause this.
Dynojet? DIS igns are notorious for messing w/ tach signals on Dyno jets. Some operators use inj pulse, or even a strobe to get it right.

The significant difference in the time to pull to 5200, may indicate a problem w/ the converter, or trans??
Any pulls w/ the verter locked?

 

[geargrinder427]

Update

I did not get the scanmaster numbers after the pulls but I will go out and warm up the car and get some numbers and post later tonight if that will help. I will also post the Vigilante converter details after I check the receipt number against the company that sold it.

The difference in the pull with and without alky is that I turned the boost down two turns on the RJC controller when I turned the alky off.

I did not do any pulls with the car in Drive, just 3rd. I did do a pull in Second gear that I can post later tonight as well, it also had the alky on and the boost up.

What else would cause the boost lag so bad and then turn on so late other than perhaps it is getting too much fuel at the bottom end causing issues...to much to light up ?? I am pretty sure it is going to need a new chip along with a coil pack. I have a feeling the previous owner had the chip set to run the big turbo on 100+ octane, not 91 with alky......

I just replaced the plastic timing gear on the cam that was still on the car before installing the alky kit....I put a steel double roller on from Eldebrock and set it to the standard 0 degree marks, dots lined up. I am pretty sure I set the timing and crank sensor correctly according the gnttype.org instructions. The car runs pretty good until you stomp on it......

The car still has the factory boost controller and I have a NOS Y hose for it if maybe I should hook it back in to see what happens ???

Thanks for the replies !!!!

Andrew

 

[Razor]

Your engine management is controller by the chip.. meaning it controls how much fuel goes into the motor, at what RPM's, how much timing, etc...

Running an engine with an unknown like a chip is like playing with a handgun and checking to see if its loaded by pulling the trigger.

First thing first. Get a matching chip made for your size turbo, injectors, alky, haeds/cam, etc etc etc. This is the foundation... Just like you build a house.. you need to know what kind of concrete is poured.. in your case.. who know's.. and beating a Buick on a Dyno with an unknown chip=blown head gasket or worse.

Next.. learn to use the scanmaster.. and make sure that is being watched on the dyno... any knock.. lift.

HTH

 

[geargrinder427]

Thanks Razor...guess I'm lucky I didn't blow it up....The KR read zero on all the pulls but again, maxing the motor without it being in top form not good.....

I contacted a forum member that knows and understands the Turbo Buicks here in Nebraska so he is going to help me get my car tuned/fixed correctly. No more dyno pulls!

Again, thanks for all the responses. I'll let you guys know what the issues are that are found in a future thread.

Andrew

 

[Razor]

Thanks Razor...guess I'm lucky I didn't blow it up....The KR read zero on all the pulls but again, maxing the motor without it being in top form not good.....

I contacted a forum member that knows and understands the Turbo Buicks here in Nebraska so he is going to help me get my car tuned/fixed correctly. No more dyno pulls!

Again, thanks for all the responses. I'll let you guys know what the issues are that are found in a future thread.

Andrew

Good Luck. Keep reading.. eventually it sinks in.. the more you read and do.. the more you learn.

Learn the scanmaster.. that is the first step..

 

[Mike Licht]

The car has a Turbo Tweaks chip

The MAP translator is a 3.5" with the switches set to on-on-off-off with 10% rich selected.


Andrew

The translator is set up wrong, should be on-on-on-off and the WOT control should be on "0" when using that chip

ML