So my Z in my sig has been down now technically for almost two years. What started as a mere Super Vic intake upgrade over the stock LT1 intake along with a 24x conversion, turned into tuning problems on the dyno due to unknown boost loss. Over the winter the boost leak was found and fixed, and because I knew I would need a new tune, I decided to upgrade my ported AFR 180 heads to some AFR 227 heads which I believe would more adequately fit my combo (big cam and intake, and maxed out D1SC).

Tuning started months ago, but the tuner was getting random injector pulses and spent the last few months figuring it out.

Well, the wait is finally over and the car is done. Unfortunately the tuner just left out of town for a week, and I will be out of town myself for a week, so I have to wait one more week to pick it up.

I took guesses as to of what power gains the car would pick up changing the AFR 180's to the AFR 227's. Some didn't think it would gain more than 10-15 at the wheels. I will gladly say those guesses were WAY off. I had a number I thought it would do in my mind, and it surpassed that by a bit. The tuner gave me a range it made so I don't have an official number until I get the dyno sheet, but the range he gave me impressed the hell out of me.

I think traction may become an issue, but we will see!

Anyways, I am pumped!

 

AFR 227s are on a whole 'nother planet then the tiny 180s!

I bet it picked up a ton, AFRs have crazy strong exhaust ports relative to most SBC heads so they love boost .

I think I commented on that thread lol.

 

Insanity to follow

 

No reason why that car shouldn't put down some number deep in to the 700s to the back tires. Marcin (?) on CZ28.com ran those heads on a similar cube motor, D1SC as well and was cracking 700s with the LT4? Intake Manifold on pump. A local car here, Dave Lewis' 95 Firehawk back in the late 90s/early 00s had a T-trim on a 383, that car made 740rwhp with GM LT4 Heads and Intake, had a Comp CC305 cam in it. Was tuned on 104 I believe.

 

You have all the big parts minus the head unit (not that's its tiny) so I would hope you saw a big gain. The tuner couldn't tell you what it put down or are you keeping it hush for drama?

 

Naw, he tuned several cars while working on mine. In trying to figure out what was wrong with he car, he had it on and off the dyno multiple times and he doesn't recall the exact amount but that it was in the 685-700 RWHP range. I'm not into playing games with suspense, but I also like accuracy, so I don't want to say it did 700 if it didn't. When I have the dyno sheet, I'll post up exactly what it did.

All was on pump gas in the heat.

 

Very nice. Pump gas with meth I assume?

 

Yeah pump gas and 50:50 meth water mix that comes on at 4#'s of boost.

 

Can't wait to see the time slips!

Thats a low 10 sec car!!!!

 

So where was this boost leak found at Ben? Mine is still down...going on 3 yrs. Was hoping to make the shoot out but not this yr. If I sell a much needed car before the yr is out I'll be pullin the motor to get refreshed and retuned since it was essentially tuned on 6 cylinders.

You should be deep in the 700 I'd think even w/ that maxed out D1sc. If I had that intake you got I'd be in a world of hurt. LOL Still amazing you don't have traction issues w/ a tad over 600 to the wheels.

 

Yeah, a track day will be in the future for sure. It has taken down a 10.0 car in the 1/4 mile on the street with its old combo, however it has never really done great at the track. Granted I was running slicks and 18" street tires up front which was always a bad combo.

We will see this year, as I have acquired skinnies for the fronts finally.

How is your car coming?


The boost leak was found in the metal inlet elbow on top of the intake. I got the one that was "non-boost" rated thinking they were trying to just get the extra $100 for the boosted version. I figured there was no way that 15#'s of boost would be enough to break a weld, but I was in fact wrong. I had the old one fixed and sold it, and had a new one fabricated and double welded inside and out (the same as the boosted version I should have got to begin with).

Good luck with your car Silas. I really do hope you get the other car sold so you can get your SRZ fixed after all this time. It would be a shame to see you put that kind of effort in it and have to get rid of it, or see it sit there not running.

I was very impressed that my car with its 614 RWHP could dead hook in 1st gear with cold Nitto's. Now that I will be probably right under the 700 RWHP mark, I seriously doubt I can pull that off anymore. I am hoping I get decent traction in 2nd, but we will see.

My buddy just converted his 03 Whippled Cobra to e85, and did 650 RWHP and 610 RWTQ. I really figured he would be all over the place as his suspension is much more of a handling tight suspension than a drag racing suspension, but I was really impressed he got "okay" traction in 1st, and hooked pretty well in 2nd.

I have not seen the dyno graph at all on my car so I really don't know where its at, but if the cam shows a similar graph, then most of my power should be made in the mid range and up top, and perhaps that will allow some traction down low as before.

I am sure I will get video of it for everyone to see what kind of monster it has become

 

Awesome its coming home finally. What did the root cause of the problem end up being?

 

As far as we can tell, a bad ground.

 

Glad to see you got the bugs worked out. Get a vid, btw!

 

Glad to hear the car is back together Ben. Sounds like you have made some nice changes. I hope to see it sometime this summer. My car is almost back together also. Its running just have a few more things to do.

 

Thanks, and I definately will


Glad to hear your car is almost back together Dan. Once I do get my car I'll definately be making up for some lost time by taking it out a TON. I'll be making a Muncie run at some point as well. I would be more than happy to give you a spin.

 

Sooooo, official numbers:

695 RWHP, 572 RWTQ.

My setup was made to go to 7,000 RPM, and he only took it to 6500 (even though the power was still climbing). I'll put it on another dyno sometime to run it up and break the 700 mark.

 

What kind of fuel were you running?

 

93 octane (pump gas), and meth injection.

 

Will LTXtech ever know?