1998 Camaro Z28 / blow-through 5.3 / maybe I'll actually finish this one

Discussion in 'The Turbo "Builds" Board' started by TurboComet, Nov 13, 2020.

By TurboComet on Nov 13, 2020 at 12:06 PM
  1. TurboComet

    Oct 6, 2005
    I've always wanted a race car. Anything I've ever built or attempted to build always took the direction of heading towards becoming a race car. As such, I sold my Fairlane project for reasons and bought myself a race car that already has the stuff done to it that always ends up becoming a hurdle or discouraging for me. Here it is.

    1998 Camaro Z28. As purchased it included a 5.3 with an LJMS stage cam, 706's, Precision 7175 turbo, ProEFI 128 system, 4L80E with some sort of 9-inch converter, Ford 9-inch with 4.11's/spool/Strange axles, a basic roll cage, Kirkey seats, Glasstek cowl hood, VFN dash w/Auto Meter instrumentation, and various BMR chassis/suspension upgrades throughout the car.

    The engine is a Gen-III externally, but is claimed to have Gen-IV rods/pistons. This engine will remain in the car for now. I'm currently replacing the 4L80E with a Powerglide & bolt-together converter. The 7175 Precision turbo has been removed, sold, and is being replaced with a Garrett Gen 1 94mm turbo.

    I'm also in the process of removing the ProEFI 128 system. The Holley EFI intake manifold assembly has been removed & sold. IRD Racing is currently building me one of their billet ethanol blow-through carbs. I have a Holley bolt-together carb intake to install on the engine in place of the EFI stuff. I have a Terminator X to run the ignition side & boost control side of things. The A2A intercooler has been deleted as well.

    The Jegs wheels are being replaced with a set of Keizer single bead lock wheels on the rear and their bolted 3-piece front runners. I'll likely run a Pro Bracket Radial on the car to see how I like them.

    Plans for the car are to street race it and participate in some local small tire no prep stuff, as well as to serve for a more relevant test bed for new Hughes products when needed.

    Why I am replacing a known high quality, powerful EFI system with a blow-through carburetor? Simply because I dig blow-through carburetors and have always wanted to try a fancy, professionally built one instead of using my typical home-brewed garbage that I've built in the past. No, I don't care about pros of keeping the EFI system on the car. No, I don't think carbs are better than EFI. I'm building what I like, simple as that.

    I'm not holding out any hopes of serious longevity for the current 5.3 in the car, so I've also acquired an L33 bare block to build a new bullet on the side. I respect the whole SBE thing, but it's not really my bag, so this new engine will feature a forged rotating assembly. I have set of Molnar power adder rods & forged crankshaft on the way. I'm thinking about trying a set of the Summit Pro LS pistons just for the heck of it. I have new custom grind from Dougherty Racing Cams for the L33, as well as a set of the Comp Cams BSR shaft rockers. The new build will either feature a set of mint low-mileage 243's I already have, or possibly a set of Trick Flow 220's money permitting.

    I'm also currently working on re-doing the hot side for the Garrett 94. Current hot side is an On3 T4 kit that actually is surprisingly decent quality and fits the car really well, but I'm doing a truck manifold hot side in its place simply because I like the durability of manifolds and the spark plug access on the driver side will be infinitely more user-friendly compared to what the On3 hot side offers.

    I'll try to post updates as I make progress. Should have the carb hopefully sometime in December at which point that should be the only item left to install so I can start testing.

    Camaro.1.jpg Camaro.2.jpg Camaro.3.jpg Camaro.5.jpg Camaro.7.jpg Camaro.6.jpg
    Last edited: Nov 13, 2020
    Vergil, Pro-SC, LSnine and 3 others like this.


Discussion in 'The Turbo "Builds" Board' started by TurboComet, Nov 13, 2020.

    1. Camaross
      Wow! Incredible build

      I just bought a junk yard LQ4

      the goal is to build it and turbo it

      thanks for the inspiration! You’ve given me a lot of ideas based off what you’re doing with your project
      TurboComet likes this.
    2. 20112011Cummins
      This is such an awesome build!

      What are all the solenoids on the powerglide for?
      TurboComet likes this.
    3. az92coupe
      It's a dump valve. Allows you to control the converter charge pressure. Have a question about that - can you control the Hughes dump valves via PWM out of the Holley??

      Update us Pete!!
    4. TurboComet
      2-stage torque converter dump valve system. First stage bypasses converter charge oil as it's entering the converter. Second stage bypasses converter exhaust oil as it's entering the cooler circuit. Provides an increase in available stall speed & faster engine / boost response for staging purposes, & can also be used as an additional means of driveshaft acceleration management on tricky surfaces or to help manage RPM drop on the gear change.
    5. TurboComet
      Yep, PWM at 10hz works great with our dump valves. Holley, Haltech, several other management systems can all provide dump valve control. We also have our own stand-alone 2-stage dump valve controller as well for racers who either aren't running an ECU with PWM options, or have an ECU that is out of I/O.
    6. TurboComet
      Got the hot side all finished up! Probably gonna leave the hater pipe in place as a tribute to my grandpa Jim. He loved 5-inch stacks and would put them on the antique trucks he restored.

      Hot side.4.jpg Hot side.5.jpg Hot side.6.jpg Hot side.7.jpg Hot side.8.jpg Hot side.9.jpg Hot side.10.jpg Hot side.11.jpg
    7. 62CometTurbo
      I thought about hood exit because of space, decided on dumping behind the front tire. Love it man! Any reason you're going blow through? Or did I miss that....I'm just curious as I'm currently on a home brew blow through and I didn't have nearly the problems people made it seem. My car is 99% street driven so I'm on the fence once I get a real bottom end put together.
      TurboComet likes this.
    8. az92coupe
      Pete will respond with "Because I want to" - or maybe "Because carbs are rad". There is absolutely nothing wrong with a properly setup blow through carb, and IRD can build a hell of a carb. The EFI guys will cause a fuss here, but a CORRECTLY setup carburetor will produce more HP (likely due to the mechanics of fuel shear out of the venturi vs. Injector spray) and can still provide reasonable transitions and behave well on the street. It's not a huge HP number, and fuel injection certainly has advantages.. but in this setup (running a Holley EFI system to control ignition, data logging, boost control, dump valve, etc..) the advantages are negligible. Some people just like mechanical fuel delivery (myself included) and are comfortable tinkering with carburetors.

      My CSU carb on E85 was an excellent street combo. People were genuinely confused when I popped the hood in the pits or staging lanes.

      Looking good Pete!!
      Twin Turbo Skylark likes this.
    9. TurboComet
      I went blow-through carb for three reasons:

      1.) I really dig 'em.

      2.) I've always wanted a high end purpose built blow-through carb and am finely at the stage in my life where I can afford one.

      3.) Blow-through carbs on LS engines make many LS enthusiasts have a spasm and/or immediately dismiss the combo as being capable of running to potential which I find entertaining.

      The car could potentially end up with EFI on it down the road, but that would be with a totally different engine platform if that happens. I have (3) LS engines currently & am determined to make the blow-through work. If I hurt all (3) engines then I have a Nissan RB30 engine that may go in the car. At that point it would get EFI.
      62CometTurbo likes this.
    10. 62CometTurbo
      Good answer! I stuck with mine because I'm cheap, and it was one of those "it can't be that hard" ideas where I just wanted to make it work. I ended up with a jet kit and a boost referenced power valve, used stainless brake line scraps for vent tubes. Something about the carb looks cool sitting behind the turbo.
      TurboComet likes this.
    11. TurboComet
      Cold side mock-up. 3.5-inch tubing from Vibrant Performance. Have a VSR 50mm BOV to get fitted as well. Just waiting on the GT55 compressor housing v-band flange to arrive from Motion Raceworks.

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    12. 62CometTurbo
      Not planning on a hood I guess? LOL, Looks awesome!
      TurboComet and 20112011Cummins like this.
    13. TurboComet
      I really dig the obnoxiousness of this configuration, but I'm going to try some other routing as well before anything gets welded. This set up obviously isn't great for line-of-sight from the driver seat LOL. I do have a fiberglass Sunoco style hood for the car, but it's obviously going to require some notching / fitting regardless of how the cold side plumbing gets routed.
      62CometTurbo likes this.
    14. TurboComet
      Cold side finished!! Now to take the turbo system all back apart for cleaning / painting / powdercoating. Fortunately it all comes apart in under 10 minutes.

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      62CometTurbo likes this.
    15. 62CometTurbo
      That carb is fucking beautiful lol. I think I've got the same BOV, 50mm? I had to shim mine to work at the vacuum I've got but so far so good. Been on almost a year. I did take it and the wastegates apart and cleaned and high temp antiseized them.
      TurboComet likes this.
    16. TurboComet
      Yep, 50mm BOV from VS Racing. I'm also using their 60mm wastegate.
    17. 62CometTurbo
      I'm using two 44mm, no complaints so far. I'm only running 6 lbs so far so I wanted as much control as I could get. Once I get my dart bottom end in I will turn it up to see what I can get. I THINK I'd be happy with 750ish whp.
      wht73 and TurboComet like this.
    18. TurboComet
      Out with the 3.70; in with the 4.33.

      62CometTurbo and Disney Lincoln like this.
    19. BlackCoffin
      How much rpm you plan on turning going with a shorter gear? With your setup you’ve got to be running the limit in a 1/4 mile.
    20. TurboComet
      The current engine should turn 7,800 - 8,000 RPM. The new engine that will eventually replace this engine should turn 8,200 - 8,400 RPM. This build is for 1/8-mile racing only.