LT1 Project Car

I'm having a problem with a 95 Z28 383/4L60E and hoping that someone can help.It is programmed to shift out of 1st. gear at 5800 and will shift
great on the street,but,will not shift out of 1st.
at the track.(code 72 is set)and goes straight to 3rd. gear. The transmission is built all the right parts and has shifted perfectly. I checked the voltage at VSS at it shows 4.93 VDC.I also installed a new VSS and still have the same problem.  

Hey scott, my name is billy and im from south florida, I ve been trying to keep up with the project LT1 thread, and I share the same enthusiasm to run 11's, and keep the factory 10bolt alive as long as possible. I currently own a 1995 Z28 automatic that has 194k miles, and still has the "salad shooter" wheels. it is basically stock with the exception of a non-intercooled vortech supercharger kit, a flowmaster single 3in catback, the catalytic converter was removed, and nitto 245/55-16 drag radials. thats it... everything else is stock, there aren't any suspension parts, original 3.23 gears, no high stall converter, no leaky P.I.T.A. headers! at moroso motorsports park in west palm beach, FL (sea level- no corrections), the car has gone 12.65@110 with a 1.99 60ft, leaving from an idle. This information might help since you mentioned forced induction. if you have any questions please feel free to ask  

Scott, it was nice meeting you and good luck with your project.  I'll give you an update as soon as we get EPP's LT1 project car back to the track.

Jon Beam  

Here is the deal: not many of us independently wealthy!   Build the best combination of power and gas mileage!    With gas prices soaring - the "real world" practicalities of mortgages, feeding families, education, etc. should "force us" into striking a balance between horsepower, budgets and gas mileage!  

It's simply too easy to use "horsepwer" as the single variable!  Heck, give anyone a blank check and "presto" -- killer LT1!    On the other hand, give someone a power level and overlay a 15 mpg hard variable -- the strategies for the build get very different!!   Most of us are budget minded gearheads anyway!  

Thanks  

I agree on the mileage and personally I think the forced induction route is the best way to achieve both performance and gas mileage.  You don't have to refill the bottle, it's there when you need it, and you don't have a big cammed car shaking the thing apart at every light.  Though sometimes that last option is alright...  

Jon  

Good to hear from you Jon, definitely keep us in the loop with your Formula and keep doing us LT1 guys proud.

Naturally aspirated: stock cube with a good set of heads and a big cam should get you into the 11s for sure with a 12-bolt, 4.10 (or higher) and slicks. But at what cost? I'd like to play it safe for now with my little 10-bolt, 3.42 or 3.73 gear, and a modest motor combo. I think everyone can agree, the more you drive your hot rod the less you are willing to put up with the big cam with idling problems, belt issues, etc.

On the other hand, with the fresh House of Kolor paint job and some of the other work we are putting into it...the Formula's daily driver days are over. So we'll see what happens after this thing hits the 11s.  

Scott, your LT1 project car looks great!  I'm curious to see what you have in store for her.  

Jon  

Well i dont want to hear about you guys being on a budget. I am sick of hearing that. How come its the ls1 that gets great articles that consist of almost 10 cylinder heads being tested. It seems like mags make it sound like if the lt1 is for poor people and the ls1 is for the rich. I remember when the lt1 came out there wasnt alot parts out for them. Today its a different story. If you guys are going to do something different, show us once and for all what an lt1 or lt4 can do. Just because i cant afford to spend big bucks on a blower,turbo,AFR heads, doesnt mean i wont get there one day....BTW I OWN 2 1994 Z28 SO THAT MEANS I PLAN ON SPENDING DOUBLE CUZ MY WIFE WANTS A NICE CAMARO TOO.  

we have a 95 z28 in the shop right now im doing for a customer, a little background on us, i do alot of efi gm stuff, and other old school bop stuff, but this z28 is going to be the most differnt chevy based engine build ive probley ever done, hardley anything is going to be off the shelf stuff, for starters i took a stock set of 93 heads and ported them myself and got some nice flow numbers out of (dont have the sheet right infront of me" but where it gets strange is, i have angle milled the heads to acheave a 13 degree valve angle, i called up a good friend at T&d AND had him send me out a nice set of shaft mount rockers for it, and custom pushrods, we went with a 2.0 intake valve and 1.60 ex. i am now working on the sheet metal intake that will use a center mounted 90 MM tb with an elbow. the cam is a custom grind we specked out from a simular TPI 383 cube build i did a few years back, it specs out with an intake CL of 109 degree with a 113.5 lobe seperation,  with 231 degrees of duration on the intake side and 226 on the exhaust, it has .561 lift on the intake side and .553 on the exhaust. as for induction we will be useing a percision 72 MM .88 A/R ball bearing watercooled turbo, with custom headers fabbed by us, we are useing a percision water/air intercooler, and one of my own water/methonal injection kits, it will be running 8 36 lb injectors, with one of my twin aux injector kits plumed into the the plenum. they are 24 lb ea and can be used independantly depending on fuel demands. all this will be controled by a stand alone ems of a brand we have not decided on yet. as for the motor we will only be pulling it and putting in a set of speed pro blower pistons that will yeld 9.2-1 static compression with the head machine work. and a set of speed pro total seal rings, assumeing the 33,000 mile short block is all within spec on the clearances. this is a low mileage 6 speed car.   you ask for differnt ????  

one thing i forgot to mention that makes this build differnt the cam is a solid roller cam not a hyd roller stick    

All these ideas sound great! I can't tell you how many mags do not ever say any thing about LT1 anymore. Hey if you need a proto car let me know ...

-Mike  

There are still plenty of us crazy LT1 guys pushing the envelope and limits on LT1 engine setups.  I am curious about the above mentioned angle milled 13 degree LT1 bare casting heads you speak of.  Let us know how that turns out.

Scott......keep up the good work on the LT1!

Tony Shepherd
fast93z.com
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It's really great to hear so much interest for LT1s. Guys like Tony and Jon are definitely showing what these motors can do.

As for the magazine, between my Formula and a couple other tests and builds we have coming up, we hope to keep whetting your appetites for LT1 tech. In the past year and a half several great products have come out that I've just been itching to test, so stay tuned.  

It's great that GM High Tech still considers the LTx platform to write articles and test parts.  I personally would like to see a stock 350 LT1 rebuild with a forged bottom-end using a budget turbo set-up.  Some simple turbo setups have become available in the last year. I say build a solid transmission, rearand and good PCM tuning and go have some fun    

ScottGMHTP:
Hi, my name is Scott Parker and I am Technical Editor of GMHTP. In the upcoming issue I will be introducing my LT1 Formula Project Car. I plan to go a different route than some of our previous LT1 Project cars such as Thunderchicken and The Grape of Wrath. In an effort to provide new and exciting tech, I would love to hear any suggestions you may have on creating a reliable 11-second street car. Please let me know if there are any product tests or setups you would like to see in the magazine.

Hey Scott,
First, I'm glad that you are doing a LT1 build again. It's time to show that the red-headed stepchild can still hang. I am currently building my own 95 Z28 that is a gauranteed 11 sec daily driven car in California. I was able to accomplish this with very little money. If you would like to know all that is being done, you can contact myself or Rob at Strictly Performance Motorsports in Vany Nuys. You have done articles on his cars before. Let's say that with only 1500 into the motor Rob has told me my car will easily run 11's and there are twins capable of plenty of boost in the very near future. So I will keep everyone posted on the progress of mine.