JoBy

I made an all new from a flying lead harness.

MikeP84

Thanks, I was going to ask what ECM you were using but I just saw you already listed it

JoBy

I bought two K&N air filters for the new C7 Corvette. A single filter is used by the 2017 Z06 rated 650 hp. Two should be enough for me. I like these filters because they mount to a flat surface like a flat panel filter, but have much more area.

https://www.knfilters.com/search/pro...px?prod=E-0665

The ducting from filters to turbo maintains the area of a 5" pipe or more all the way. It was a lot of work to make the air duct over the radiator but it was worth it.

I also replaced the stock 48 mm TPI throttle body with a 58 mm. I never liked having an oval joint with hose clamps so I welded aluminum piping directly to the throttle body.



















































And finally a before picture:

MikeP84

WOW!!! looks like you just bought it! great construction. gives me ideas for mine!

Gibbles

It looks like you still have the 84 hood, had any issues with fitment due to the cold air channels in the hood?

JoBy

Radiator is lowered 2-3 inches to make room for the air duct. And the duct uses all available space. The TPI hood would give more clerance.

C409

..... Very Impressive fabricating skills ! .....

ON 8TH

JoBy, I remember you from the CrossFire forum

JoBy

Thanks!

Yes, that was many years ago now.

Mike Holmen

Outstanding fab skills there JoBy, wow very nice job. I'm planning on building a sheet metal cold intake for my car. Questions for you?
-You running a ram air cold intake? Aka cutting the license plate area out and forcing air into your cold air intake?
-Wow that sheet metal intake is a beauty. What turbo you using?
-On your exhaust, looks like your not using rubber isolators?

I have a 85 vette and just installed a LQ9. I'm just using a 90 deg rubber elbow into an air filter just so I can drive the car. Last weekend I just completed my home built by me, 3in exhaust. I built it out of a bunch of 3in pieces I bought over the counter. I have $120 into it.

I'm just going to use home made steel exhaust hangers/supports for now. So far it seems to work, originally I thought I would have more rattles going that way than I have.

Thanks for inspiring us.

JoBy

Cold air but not ram. This is looking up under the front with the filters in front of the intercooler:




Garrett TBP7501 turbo.
Compressor: 75mm inducer, 102mm exducer, 0.75 A/R.
Turbine: 98mm inducer, 87mm exducer, 1.26 A/R.


At the rear I am still using the stock hangers after the mufflers.

The dual 3" with X-pipe I built back in 2005 after installing the 4L80E was only hanging in the headers up front and after the mufflers.

The current exhaust with a 5" center pipe is bolted solid to the rear of the transmission to maximize ground clearance. See picture below. At the front near the converter I have a short flex pipe. That makes moutning of the headers or downpipe much easier and temperature expansion is not a problem. I don't notice any major sound differance from the solid mount. Probably the flex pipes help, and also the transmission does not have a solid mount to the frame. The exhaust headers are monted solid to the heads so that is not a big differance. I would say that the main reason for the stock center rubber mount is temperature expansion.

JoBy

So, was there any change with that new air intake?

Well ... With the old setup I managed so get about 18 psi boost with the wastegate fully closed. I had to use boost control valves on both sides of the wastegate diaphragm to get enough closing force. Above about 15 psi I did not notice any performance increase.

With the new intake I had to remove all boost control. With a 7 psi spring and fully open wastegate I still got more boost than before. This is one of the first test runs on a back road in an industrial area.

I start at 3000 RPM and 3 psi boost ( 119 kpa absolute )

Blue slope is speed measured at the front wheel.

Yellow is calculated wheel spin.

Top red line is RPM and as you see it saw-tooth up and that is the traction control working like crazy.

Middle red is spark advance and it is retarding 20 degrees to control wheel spin.

The blue spikes are spark drop when spark retard is not enough.

60 mph (96 km/h) after 3.254 seconds.
100 mph (161 km/h) after 6.065 seconds.

sprink94

Mister...that is some seriously nice engineering work!! Well done !!

JoBy

Thanks!

Some more information about the graph.

The smoth RPM around 3 seconds is because I had a 7000 RPM pill in my MSD 6AL. RPM peak was about 6900 RPM and MSD was soft clipping and dropping spark. That is why traction control does not have to work in that area.

RPM drops when shifting to second and engaging TCC lockup. I had some problems with the TCC control and just after the last blue spike TCC released causing RPM rise. Then RPM came down when shifting to third, so last smooth part is third without TCC.

JoBy

The new Hoosier DR2 295/50-16 does fit without problems. I have raised the rear about one inch and I have also mounted longer rubber stops to prevent the rear from squating too much.

1993C4LT1

Can't wait to see some runs

Mike Holmen

Outstanding job, Joby. Man you have a ton of hours in your car.

Very impressive car.

JoBy

With the stock rubber stop the tire could get a bit too close to the fender.



I also installed new QA1 double adjustable shocks at the front.
A bit more travel before fully extended.

Mike Holmen

You have any more pics JoBy of your front coil overs? I'm wanting to try those QA1 stocks, but I heard that the coil overs will hit the front sway bar on the earlier year C4's

JoBy

I still have the stock transverse spring. I only use the QA1 shocks. No fitment issues with them.