Most qualified mechanic to appraise a C4 ZR1?

Hi all

I’ve had my ZR1 advertised for a week or so - had load of interest but the same story from most buyers… Nervousness that it has been off the road for many years essentially.

I feel that although people enjoy my videos there is a general assumption that my car is, how do I put this, probably not running well and a bit patched together basically. I had a comment from a club member at a show recently too;

"Got your ZR1 running properly yet?"
"Err - It's running very well thank you"
"Really?! I highly doubt it"

I was slightly erked and haven't forgotten that comment.... I shouldn't need to justify anything but I will.

While it could benefit from some paintwork this irritates me because I know for a fact it is mechanically as strong as any other C4 ZR1. Not just the engine but the drivetrain, suspension, brakes, electrics. And had probably had way more work than the majority of them have, certainly in recent times.

I plan to put it on a dyno to demonstrate the power.

What I’d also like to do is get an inspection report from the most well qualified C4 ZR1 experienced mechanic in the country. Any idea who that might be so I can reach out to them? (Preferably one within reasonable reach of Nottingham)

Any advice appreciated!

Llewelyn

Sorry I don't know of any mechanics etc, but I look forward to the Dyno Episode being on Youtube. Your ZR1 looks very nice and I'd like to own it, but alas I don't have space for it, and the missus would kill me.

CaptainK said:

Sorry I don't know of any mechanics etc, but I look forward to the Dyno Episode being on Youtube. Your ZR1 looks very nice and I'd like to own it, but alas I don't have space for it, and the missus would kill me.

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Thanks! The dyno vid will happen once I can get it booked in

Llewelyn said:

What I’d also like to do is get an inspection report from the most well qualified C4 ZR1 experienced mechanic in the country. Any idea who that might be so I can reach out to them? (Preferably one within reasonable reach of Nottingham)

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How about Parts USA Manchester way? They are a GM authorised Vette repair and service company and have a great reputation. Neil there is ex Bauer Millett Manchester, who were the sole GM authorised UK Vette dealer for many years until closing in 2015(ish).

Keith at Eurovettes (when he's back in the UK) has been dealing with C4's for years - also has good knowledge of special C4's (Callaways) and presumably Zr1's?

@Chevrolet @Roscobbc both good choices, it would ideally need to go on a ramp and be test driven etc by whoever looks at it!

FYI
Back in 1998 I put on a Corvette chassis dyno day
Results are from a NON load bearing dyno and is rearwheel output
Several were C4 ZR-1s we owned

Keep in mind early years ZR-1s had 375 HP, where 93-95 had 405 at flywheel
but due to the waxers bitching about tranny gear rattle at idle, the 405 version had less torque than the 375 HP did

The ZF tranny was designed for maximum torque output and the lashing (spacing) between tranny gears was real close
that was than causes the rattle at idle where GM had more spacing in-between gears to remove that rattle
but at a loss of torque output

VERY interesting results! And also your comments about the gear spacing - I didn't know that!

Mine is booked in for monday so I will post the results here (and film it)

Be nice if you reported was the chassis dyno used was load bearing or not, was calibrated and
takes into account for a correct D/A as to weather and elevation

Also, a secret
At the time I worked for GM engineering and worked with Tim Holland of Lotus who was the LT5 program manager
He was pissed that GM was dumping the ZR-1s so he had the 95 LT5s with different ECM tunes
He sent me an ECM E-prom to test with me 94 ZR-1 and hence the output was higher and people
would say GM must have hacked on mine as my racing numbers were better than other stock ZR-1s

Good book on the LT-5

I'll have to get a copy of that Interesting re the ECM tunes too!

Here is the secret E-prom tunes Tim sent me to test on street and track
I used that tune as baseline when I tuned customer's ZR-1s
You can see his address in the UK and me at the GM tech center in Warren, Mi
I still have this one of a kind ZR-1 E-prom and tune it has
.

Roscobbc said:

Keith at Eurovettes (when he's back in the UK has been dealing with C4's for years - also has good knowledge of special C4's (Callaways) and presumably Zr1's?

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Definitely. And back in the day, Keith rescued a ZR 1 mule off the scrap heap and brought it back to life:

We've had the car on the dyno - Video link below but the headline results are

Power key on - Circa 335hp at the crank
Power key off - Circa 210hp at the crank

So in conclusion it's healthy although not making stock power - there is the subjective element of the dyno, calibration, traction etc. Also we are running a haibeck chip which was gifted to us but we don't know if it could be causing a problem due to it not being for a 91 car (would this make a difference? @teamzr1 ). I also have a Doug Rippie chip so I might go back and do 3x runs - Stock, DRM and Haibeck to compare the differences.