LQ9 6.0L PT88 w/ Truck Manifolds in an FBody Build by 98Z28CobraKiller

7 minute(s) of a 55 minute read

I took off the hot side and brought it to Dave's house again. He cut off the 1 3/4 pipe that I had feeding the 44mm wastegate,he bent me a piece of 2 1/2 and welded it on. We popped open the new 60mm wastegate to see what it had for springs. It was loaded with 2 springs. The WG came with one more spring in the box. That one felt comparable to the 11 lb spring in my 44mm so I took the other 2 out in favor of the one middle sized spring. I hope to get it put together and take her out for a spin early in the AM tomorrow. If I can get the boost down under 12 psi, I'll be at the track Wednesday for some shakedown passes.

Did some tuning today. The spring that I used got me to 13 psi. I need to try one of the other 2 springs. Should get me down to about 10 psi. I would leave it at 13 but the fuel pumpwont support it. Injectors are pretty much going static to keep the air fuel correct. Still a touch fat up top (10.5-11.00). I went ahead and tuned it with the 13 psi spring in it only going to 6K RPM. It feels pretty nasty and pulls clean the whole way up. Another good reason to drop boost is because the converter is too loose with this combination shift point/power setting. I should be ready for Wednesday.

4/21/2009

I'm running the single racetronix walbro setup and stock lines. I've already bumped up to the 80# injectors. At 13 psi I was seeing 130% duty cycle. My problem is the pump. I'll be getting a MagnaFuel 1200hp pump here shortly and upgrading to a boost reference return style system.

I'm hoping to see some 10.o's tomorrow in the 1/4 with some low to mid 130 mph. If the power is there, the suspesion will put up the number.

I put the lightest spring in the wastegate this afternoon and it gave me 6 psi. Injector duty cycle went down to the 42-44% duty cycle range. Kinda weak. Since changing springs is kind of a pain in the ***, I decided to make myself a ghetto manual boost controller just for now. I ran down to Home Depot and Advanced Auto and spent $25.00 for this stuff.

Put it together to look like this.

And spliced it in to the compressor boost ref port. After a couple of adjustments (very sensitive), I got to 9-10 psi at 55% duty cycle. So I'm pretty much ready to go for tomorrow.

4/22/2009

First, don't use the valve that I used in my ghetto boost controller. I was screwing with that damn thing all night. You turn that thing a hair and it swings 5 lbs+. I finally got it to 11-12 psi and ran a 10.55 @ 132.23 w/ a 1.64 60' on Nittos. I had to leave much softer than I am used to. The Mickey Thompson will be on for the next time out. I was hoping to go a little quicker but 2/10 off the 60' would net me the 10.0 pass that I was hunting for. Race weight was 3680 lbs. DA was about 950 for this pass.

4/26/2009

I think that there is video of an earlier pass in the mid 11's on 6 psi. I have to try to locate it. Don't think that the 10.55 was caught on video. I did get a few pictures in my email.

I'll get the 10.0 for sure Wednesday night. I can drop 2 tenths off the 60' on the mickey's and turning up the 2 step from 3400 to 4000 rpm will get me another couple lbs of boost out of the hole. Should be good for a high 1.3 60'. Turning up the rev limiter may help me get another mph or 2 also as I was off the gas going thru the traps.

4/27/2009

Rev limiter is set at 6400 and am trying to get out of the gears by 6K RPM. I run a TH350 w/ rmvb and tbrake wired to a 2 step. I had the 2 step set at 3400 when I went out to the track on the nittos this last time out. I can bump it up to 4K and hook the mikckeys no problem.

I do have lots of bugs to work out though. One of which is that my converter was setup to stall at 5K RPM N/A (running 10.31@131) and about 5800 on the big shot. The converter is flashing up to about 4500 RPM on the launch and then never drops below 5800 RPM. Basically, as soon as it really starts pulling, I shift.

The other problem is my rear end and gearing. I run the S60 which apparently cant be geared below a 3.54. Currently running a 3.73 gear.

And then there is the fuel problem. Currently running the 80# Motrons but only a single Racetronix/walbro 255 intank thru the stock lines. I already have an aeromotive vacuum reference fpr and will order the Magnafuel 4301 on Monday. Not sure if I have any other choice but to sump my tank. 

And last but not least is the issue of boost control. I'm considering buying the AMS-500 or 1000. Need to do some research to see if the 500 will be good enough.

4/29/2009

Went to the track tonight. Had the boost setup exactly the same (13lbs for most of the pass creeping up to about 15lbs). Pulled one degree of timing down to 13*. Turned the 2 step up to 3900 (about 9 lbs)and put the MT DR's on.

1st Pass

60'............1.432

330'............4.197

1/8.............6.475

MPH.........108.09

1000...........8.431

1/4......;....10.100

MPH.........130.24

2nd Pass (lost the slip from memory)

60'............1.46

330'...........

1/8.............6.46

MPH.........107.5

1000..........

1/4......;....10.11

MPH.........127.xx

3rd Pass

60'............1.417

330'............4.166

1/8.............6.437

MPH.........108.08

1000...........8.395

1/4......;....10.071

MPH.........128.31

5/1/2009

Some pictures that I've found so far from the track.

5/3/2009

My current fuel system is inadequate to support my current needs. I have already purchased the Aeromotive Boost Ref Fuel Pressure regulator and the MagnaFuel 4301 inline pump. My original plan was to sump the tank and toss out the walbro 255 and stock regulator setup. The more I think about it, the less I want my tank sumped. For some reason, I have a major hang-up about dropping the tank and welding on it. I am thinking of doing this instead. Your thoughts and any pitfalls that I may run into would be appreciated. Thanks.