1970 GTO Version 3.0

[Kenova]

.......... The current plan is to build the 5.3L with forged rods and pistons, and possibly a forged crank, along with other durability measures, like main and head studs.

Andrew

If you don't have pistons yet maybe use a 6.6 crank. Forged with eight counterweights and more stroke.

Ken

[andrewb70]

If you don't have pistons yet maybe use a 6.6 crank. Forged with eight counterweights and more stroke.

Ken

The 6.6 crank has a 3.90" stroke. This doesn't generally go too well with the 5.3L 3.780 bore. More bore is better than more stroke, given the same displacement increase. I considered the 6.6 crank for my 6.2L, it's a very nice piece.

[protour_chevelle]

Matt,

I totally get what you're saying. Stock stuff makes a lot of power and seems to last in certain environments. But I am building this to last for a long time. Street engines get loaded differently that drag engines. I don't want this combination to drive like a little engine with a big turbo. My goal is to have the same driving experience as having a 600ci big block, which means boost coming in early. This tends to stress everything much harder than bringing in boost at 5500RPM and revving the engine to 8K. I could be wrong about all that, but that's the angle from which I am approaching this.

Thanks for the words of support from everyone else. I am definitely in unchartered territory as far as my own experience, but that's what makes it fun.

Andrew

Definitely have you're approach and what you want to do, do your thing!

To comment on methodology. I feel youre going to struggle to replicate the feel of a 600ci bbc engine with a 327ci engine and small turbo that wont fall on its face above 6000rpm, depending on your power goals and power range. Im doing the same idea of a combo with a 6.0l right now. Mine is designed to turn 7800rpm and drive like stock with quick, progressive spool. Jody is also doing a similar combo but with even more CI.

Boost coming in early is harder on the rods due to cylinder pressure. Thats how you keep a SBE engine alive, push the cylinder pressure/tq into higher RPMs, easier on the rod and doesn't cause it to fail. The failure point in a 600-700rwhp ls turbo engine is in poor valvetrain design from cam specs to people over complicating rocker ratios and cheap injectors.

[andrewb70]

Matt,

Thanks for the input. Here is how I see it. The 5.3L made 425hp at the crank and I see no reason that I can't double that with boost. There are numerous turbos that will flow the needed amount at the top and should still offer excellent response on the low end. What am I missing?

The cam is staying the same, and it's the Summit Ghost cam, which is also their stage 1 turbo cam.

[protour_chevelle]

Matt,

Thanks for the input. Here is how I see it. The 5.3L made 425hp at the crank and I see no reason that I can't double that with boost. There are numerous turbos that will flow the needed amount at the top and should still offer excellent response on the low end. What am I missing?

The cam is staying the same, and it's the Summit Ghost cam, which is also their stage 1 turbo cam.

Im not telling you not to, just stating you seem quite particular with what you want(or maybe I just read your post and mind wrong). Comparing a 600ci to a turbo 5.3 is 2 totally different animals and also very subjective. Words are also subjective, excellent to one could mean moderate or phenomenal. When I think 600ci engine, I think back to the 760rwhp N/A combo in a friends car and comparing that to the last quick spool 5.3 that made 790rwhp, you cant even compare the 2. Me personally... I love the power and control of the 600ci, I hate the big cam shaft, I hate the huge headers, etc. The LS just packages nicer, modern, mild cam, better fuel mileage, less babysitting, day to day manners, etc.

Only one way to find out. I can guarantee you'll enjoy the boost regardless.

[andrewb70]

Im not telling you not to, just stating you seem quite particular with what you want(or maybe I just read your post and mind wrong). Comparing a 600ci to a turbo 5.3 is 2 totally different animals and also very subjective. Words are also subjective, excellent to one could mean moderate or phenomenal. When I think 600ci engine, I think back to the 760rwhp N/A combo in a friends car and comparing that to the last quick spool 5.3 that made 790rwhp, you cant even compare the 2. Me personally... I love the power and control of the 600ci, I hate the big cam shaft, I hate the huge headers, etc. The LS just packages nicer, modern, mild cam, better fuel mileage, less babysitting, day to day manners, etc.

Only one way to find out. I can guarantee you'll enjoy the boost regardless.

You're right about all of the above. Time will tell and it'll certainly be a learning experience.

Andrew

[Interceptor5588]

My 5.3 has a Ghost Cam and small-housing 7875. It feels like there's ALWAYS just a wee bit of boost just puttering around and it comes in immediately when you get on it at all. 3000 stall, I shift at about 6500, and it's only about 550 rwhp. But, it's still not immediate tire-smoking big-block power. I think that if I had started with a 6.0 or 6.2 it would be.

[andrewb70]

My 5.3 has a Ghost Cam and small-housing 7875. It feels like there's ALWAYS just a wee bit of boost just puttering around and it comes in immediately when you get on it at all. 3000 stall, I shift at about 6500, and it's only about 550 rwhp. But, it's still not immediate tire-smoking big-block power. I think that if I had started with a 6.0 or 6.2 it would be.

I guess I will find out. I clearly have some ideas of what I want, but I can very well be wrong.

Andrew

[ryeguy2006a]

Are you planning to retain the shaker hood with the new motor?

[andrewb70]

Are you planning to retain the shaker hood with the new motor?

I am going to retain the shaker scoop, but I see no way that I can keep it functional.

Andrew

[wfo guy]

I'm late to the party. I was unaware that you had moved. Also unaware that you had started on the GTO. Looks to me that the only thing you're missing is a full aftermarket frame. It will be interesting to hear your comments after completion about the suspension changes . I've been working as hard as I could on a project so my time has been very limited with forums. Hope the supply chain doesn't stall you out.

[KacyZ28]

I guess I will find out. I clearly have some ideas of what I want, but I can very well be wrong.

Andrew

Andrew how did you like the ghost cam NA? I am collecting parts for a 6 liter swap in a c3 with 706 heads maybe a turbo down the line.

[andrewb70]

Andrew how did you like the ghost cam NA? I am collecting parts for a 6 liter swap in a c3 with 706 heads maybe a turbo down the line.

I swapped the Cougar 5.3L in my GTO to the Ghost cam a few years ago and it was better in every way than the ASA cam that I had in it before. It has a nice smooth idle with a little lope and very good manners. It is easy to tune and pulls strong all the way to 7000RPM.

Andrew

[andrewb70]

Truth be told, this project is pretty overwhelming. I am delving into new territories for me and I find myself questioning every decision I make. I've never had a hot rod with an automatic transmission, but I knew that for a turbo build, that would be the right choice.

Having said that, I also have trust issues with vendors. I tend to go with vendors that I have dealt with in the past or that have been referred to me by friends that I trust. This was the case for choosing a vendor for the 4L80e. I went with Redline Powertrain in Batavia, IL. My good friend, BA, had a 4L80e built by them and is very happy. The owner of Redline is Carl, and he is clearly passionate about what he does. I like that.

Carl listened to what I was doing with the car and suggested a list of components. I know there are some upgraded billet bits.












He assured me that this trans will handle the power that I want to make and will be super reliable.

Andrew

[STREETFIGHTER50]

Nice progress Andrew. I really like them brakes you installed. What did that set up run? So no more TKX? I think the manual would be much more fun. Idk I never had a turbo car.

[andrewb70]

Nice progress Andrew. I really like them brakes you installed. What did that set up run? So no more TKX? I think the manual would be much more fun. Idk I never had a turbo car.

Those brakes were installed back in 2008. I haven't got a clue what they cost, but I do know I got them from Tobin at Kore3. He has always been great to deal with and he will take good care of you.

Yes, a manual would be fun, but at the power level that I am planning on making, the TKX is not going to hold up. It is already sold, but I need to deliver it to Alabama after the holidays.

I have never had a turbo car either, so this is all a new experience for me. I am really eager to see how it all works. The turbo should be getting built tomorrow.

Andrew

[ekmxryda]

Good luck with the turbo build Andrew, lookin good!

[Motown 454]

Andrew are you using a trans brake?

[Way2qwk4u]

I like the 4L80e in my car. I like the adjustability of the newer E autos. I'm sure it will work well.

[andrewb70]

Good luck with the turbo build Andrew, lookin good!

Thanks! I need an intercooler credit card...

Andrew are you using a trans brake?

No trans brake. The turbo I am having built should spool very quickly.

I like the 4L80e in my car. I like the adjustability of the newer E autos. I'm sure it will work well.

Part of the reason for doing a 4L80e is learning more about the trans tuning.

Andrew