AnthonyGS

I'm torn on this one. I know my engine is weeping under the plenum. I have new gaskets, new PCV hoses, PCV valves etc. from white and jerry's.

I realize it's going to take a weekend or a full day off work to do. The bad part is that I am traveling 33% or more this year for work. So I could be spending that time with wife and kids or getting back to the gym. I was 30 lbs lighter and one knee surgery less before my lil girl was born 3 yes ago.

Also if I can afford it, I'd like to have the plenum and injector housings ported. I contacted a reputable shop in New Braunfels and of course the answer was we can't say until we have the car. I get that, but I can save some doing it myself. I've been working on cars over 40 years now so that's not my worry.

Can I get the plenum issues and porting done for 2k or less? Then sending it out becomes very tempting. If it's going to be over 1k just for hoses and gaskets, most of which I already have then DIY is a no brainer.

What say you guys with your own ZR experience?

FASTAZU

Do it yourself, just part of ZR-1 ownership. Lots of great write-ups here in the sticky at the top of page and on the net.

secondchance

Based on my experience mechanics who are familiar with LT5, and worse yet, have pride in doing the work right is getting tougher to find. With intricate vacuum system under the plenum, doing it right takes knowledge, patience and a lot of care. Also, when I get under the plenum, I insist on cleaning oil fume mixed with dirt. Not that I have x-Ray vision, it's just knowing that all are clean and neat, makes me feel good.
So, since my first plenum pull in 2009, I must have serviced under plenum around two dozen times - mine and other WAZOO Zs.

As much as I am comfortable doing this work, doing it alone can be tedious. Thank God for WAZOO! When we get together, about half a dozen Z guys, helping, joking around, taking Z, takes tedious out of tedious work.

At times, even if I have to do the work by myself in dark condo parking garage, I still do the work myself. Namely because I know, to do it right, I can trust only myself.

As for the porting, you can always send it off to Lgaff or Dempsey.

Paul Workman

with We Gone and secondchance. You sound like someone with knowledge and experience with tools, and pulling the plenum is a "rite of passage" for a ZR-1 owner.

Dynomite's sticky has instructions on plugging the IH coolant to the Throttle body. I suggest you do that, b/c it has proven that running coolant through the TB to be unnecessary except maybe when driving in extreme cold/damp conditions (winter). And, doing so eliminates having to drain coolant to work on/under the plenum and then get the air out of the water jacket when replacing it.

(Need one more? It also keeps the temperature down in the DIS module bolted to the underside of the plenum. Mine has been bypassed for 6+(?) years now and have had zero issues as result.) But, more important, removing the plenum is now just a 10 minute job...tops.)

If you've done some porting in the past, then porting the aluminum plenum and the IH's isn't too difficult at all with the right tools. And, as long as you don't deviate from the existing axis of the stock ports you should be OK. And, perhaps for a few more ponies, you can even extend the port matching in the top of the heads to taper from ~ 36 mm at the entrance to blend with the stock diameter at the base of the valve guides without much danger of accidentally punching through into the water jacket or (worse!) the oil galleries. (Where it gets tricky real fast is extending the cross sectional area of the porting down the entire length of the head runners, especially when the cross sectional area is equivalent to a 36+mm diameter (read between the lines...)

When porting my heads, I contracted with Marc Hiabeck to weld up any places where I might breach water or oil. If I recall, there were several breaches before I was done. Welding aluminum inside the curved runners is an art and best left to an experienced professional. I don't recommend porting LT5 heads for a neophyte unless they have such welding expertise close by!)

Practically anything done to improve the flow of the intake or exhaust requires twinning the effort with a change in the calibration ("chip") to match it. That includes not only porting, but removing the Secondary Port Throttles* (SPT) OR simply tying them open (leaving them in place so reverting back to stock can easily be done later).

*Removing the SPTs was one of the best mods I ever did to my LT5, other than porting. In fact, the dual runner scheme was completely eliminated in the final version of the LT5 (that unfortunately never made it into production.

cv67

2k to do that is a ripoff wow
hold off on that

Did you try Corey Henderson? He should be able to give you a price hes done plenty of them.
Sometimes guys say "Ill get back to you on that" as they dont do their own porting, send it out and wait for a price they just mark up. More common than youd think.

AnthonyGS

No one gave me a price. I'm saying if it can be done under 2k I would strongly consider it. It looks like most want around 1k just for the porting. So the other k would go to labor and plenum maintenance pretty quickly. The response was bring it and we'll see not even a low to high range. Pretty hard to plan two 8 hr round trips around that although 8 hrs on the road in the car would be fun. I didn't want to mention any names of said shop since I don't want to risk infringing on forum rules etc.

I'm not going to do any porting myself. The castings are too pricey for me to do that.

So far the run away choice is DIY it seems. Car already has a chip out of Chicago area and cat back. Not sure about anything else but appears mostly stock. Have original invoice on chip and it was done on ECU via mail.

cv67

thats just bait to feel you out and see what they can get too bad the hobby has people in it like that. Pass

If you want to DIY let me know Ill help however I can
Wish I was set up...soon but not right this sec
Thnk guys get stuck paying way too much just cause it says ZR1 on it.

mike100

I don't see how anybody could charge less than that. Unless you can program a machine to do it quicker- it took me at least 30 hours to port the i/h pair, 6 hours to port match the 8 primary inlets on the cylinder head, and whatever standard amount of time to r&r the injectors, plenum and whatever else you are taking care of 'while-you're in-there' kind of thing.

HAWAIIZR-1

For the new and novice ZR-1/LT5 owner, Marc Haibeck's DVD for under plenum service is awesome.

http://www.zr1specialist.com/HAT%20W...enum%20dvd.htm

Pull it yourself and while you're checking everything drop it off at Henderson Performance and Corey will squared you away with porting for a reasonable price:

http://www.hendersonperformance.com/

AnthonyGS,
I forgot to mention you have all the help you need right here or on the ZR-1 Registry. You will find the ZR-1 brothers will give you the shirt off their backs to help a brother out.

secondchance

Still learning, Paul.
I don't have a lot of tools just enough to get by in the car - roof ratchet, 6 mm allen (since I've gone to SS bolts), 4mm Allen (for MAP sensor bracket), 7mm, 8mm and 10mm sockets, a couple of torx screw drivers (for TB cover and throttle cable brackets), flat head and philps head screw drivers, pliers).

Phil modified the injector housing to bypass coolant to TB and removed secondary vacuum system the heads were ported - definitely allows for fast plenum removal and easy of service.

5abivt

Absolutely reccomend DIY. Pulling the plenum to me is far easier than even looking at my LT4 motor I built and thinking about putting it back together. Do it once.. and it will become familiar and in the future you wont even think twice.

ZR-71

Doing the plenum pull yourself is worth the time to get personal and knowledgeable with your LT5. You will know what's under there and how it all works. To me the thing to be most careful with is the vacuum lines.
Also, having the porting done by someone reputable will save you much time.
Best of luck in whatever you decide

Z51JEFF

Nobody touches th car but me. When I first got it and the injectors died it was no question. Got the FSM,took a lot of pictures along the way and dug in. If your not in a hurry just get everything you need and get after it. When I did my first pull I think I spent 3 weeks working on the car with cleaning everything before it went back together. I can't concieve the idea of anybody working on my car. Every time I take the thing to get it smogged it's a very stressful day.

RichS

New to the ZR-1, but been working on all my own stuff and friends stuff forever. With all the info and help on the forum don't worry about pulling it apart. Tons of info on the registry if you get stuck. I spend some nights just reading old posts learning stuff. I pulled my motor in Dec, like everything for the first time mark everything and take pics.

ghlkal

I agree with everyone who said "DIY."

As a ZR-1 owner, you really should pull your own plenum ... it is a rite of passage. It isn't hard, but the first time is time consuming and a little scary. I had to check and recheck every step, but it worked out fine.

billschroeder5842

I've never done that fix, but I'm sure it is some where down the road. I'll keep an eye on your posted or give me a call; and I'll give you a hand.

AnthonyGS

Wow. It's unanimous so far. It looks like I will be pulling the plenum and doing the coolant bypass this spring sometime or early summer. It also seems a few local guys are willing to lend a hand or at least eat some snacks and drink a few beers while laughing at me. Sounds like fun.

Im also strongly considering adding a Porsche 944 turbo to the collection. The 911 gt3 just isn't in the budget or any Ferrari.

Rkreigh

Have Corey Henderson port it, tune it, and enjoy!

He will take good care of you and he's very reasonable and definitely knows his way around an LT5

1993C4LT1

You know I'm down to help, and not just laugh at you