[JLMounce]

Looking for opinions on building a turbo ready shortblock. Goal is 800hp on pump gas or e85 in a Grand Touring type build. This is a street car, so it needs to have street manors.

What I have to work with:
.030 over 455
As cast KRE D-Ports
Torker ii
comp 232/238 on 112 roller (XFI lobes)

I'm thinking about a single S475 at around 8-10 psi. The bottom end of the engine currently is basic. Factory N crank, prepped stock rods, TRW pistons. Compression currently is 10.23:1. The bottom end will need beefed up.

What I'm thinking:
Check and reuse factory crank
Molnar or similar rod
Piston with either a dish to get me around 9.3:1 or custom compression height to put it down in the hole a bit. Or I run e85 and keep compression closer to 10:1

I'm specifically looking for info on the above. Do I fill the block? Mega brace? Will the factory crank live in this situation? I'll likely have a new cam spec'd.

Again, this will not be a race car. It's a street car. RPM around 5500-5700, no need to spin it higher, I'll let the turbo do the work for me.

I'll keep the factory TH400 and have it built to hold the power and shift properly under boost. Rear end should be decent as it's a Moser 12 bolt, I'll drop from the 3.73 with 26" tall tires to a 3.08 with a 28" tall tire.

Thanks in advance!

[JSPONT]

Get a good rod and all arp studs for the mains. 8-10 will give you the 800h.p.
I had the same set up for a while. Even at 8-10 psi you will kill the tranny and possibly the rear. Ask me how I know. LOL

I have been running that boost for a while, no block fill or mega brace. I do make sure my motor mounts are tight and had a chain on the left side of the motor. This past season I added a mid plate. The problem is you will not stay at 8-10 psi.

[JLMounce]

Moser "claims" my rear will hold up to 800 wheel. Claims and reality are obviously somewhat different. The plan right now for transmission is to discuss options with jakes performance for a build on my current TH400 to handle the power.

This car already has a good bit of harshness over hard bumps due to aluminum body bushings and delrin bushings everywhere. I may go directly to motor plates since the engine will have to come out anyhow.

This will go in to shore up the rest of the chassis.

https://www.cachassisworks.com/p-159...-subframe.aspx

[Tom Vaught]

We installed a similar system years ago on a 1996 Mustang that had the subframe connectors and we wanted an even more rigid chassis. We welded the parts to the chassis.

It worked better than I expected. 735 HP street car with a Vortech T-Trim supercharger.

They make nice stuff. I have a chassis works ladder bar suspension/ complete drag chassis under my race 64 GTO. Old school but worked for its time frame well.

Tom V.

[ponjohn]

For the more experienced turbo guys - should he be looking at a different cam?

[JLMounce]

I was planning on having a new cam spec’d based on the combination as well. More than likely I’ll be running something like a RA manifold on the drivers side with a fabbed header on the passenger bank, so I’ll need to keep that in mind.

[Tom Vaught]

Food for thought, When Travis Quillen installed the Single Turbo on John Welter's Firebird, (John ran 6.82 many years ago several times), Travis built the pipes going to the Split Scroll Turbine Housing using fairly small diameter pipes to the two inlet sections of the turbo exhaust housing. This turbo, if I remember correctly was like a 117mm turbo compressor wheel. BIG MUTHA.

The point being you do not need large feed pipes from the engine manifolds to the turbo.

No 4 tube header stuff required. Make it simple. Especially with fairly low boost pressures. (Like 20 psi or less). Two exhaust manifolds would work well. The hard part is getting the pipe routing in front of the front engine cross-member.

Tom V.

[BruceWilkie]

Your cam should work ok. Call Butler for his opinion.

[charlie66]

Originally Posted by JLMounce

Looking for opinions on building a turbo ready shortblock. Goal is 800hp on pump gas or e85 in a Grand Touring type build. This is a street car, so it needs to have street manors.

What I have to work with:
.030 over 455
As cast KRE D-Ports
Torker ii
comp 232/238 on 112 roller (XFI lobes)

I'm thinking about a single S475 at around 8-10 psi. The bottom end of the engine currently is basic. Factory N crank, prepped stock rods, TRW pistons. Compression currently is 10.23:1. The bottom end will need beefed up.

What I'm thinking:
Check and reuse factory crank
Molnar or similar rod
Piston with either a dish to get me around 9.3:1 or custom compression height to put it down in the hole a bit. Or I run e85 and keep compression closer to 10:1

I'm specifically looking for info on the above. Do I fill the block? Mega brace? Will the factory crank live in this situation? I'll likely have a new cam spec'd.

Again, this will not be a race car. It's a street car. RPM around 5500-5700, no need to spin it higher, I'll let the turbo do the work for me.

I'll keep the factory TH400 and have it built to hold the power and shift properly under boost. Rear end should be decent as it's a Moser 12 bolt, I'll drop from the 3.73 with 26" tall tires to a 3.08 with a 28" tall tire.

Thanks in advance!

This cam will work great for you : .050 int 243 exh 234
lobe lift .3883 .3787
separation 114 OP - CL OP - CL
Timing events 11.5 51.5 55 -1

[JLMounce]

Originally Posted by charlie66

This cam will work great for you : .050 int 243 exh 234
lobe lift .3883 .3787
separation 114 OP - CL OP - CL
Timing events 11.5 51.5 55 -1

I was definitely looking in to a reverse pattern cam. I'm going to get a few opinions of course. If I can meet my goal without spending $350.00 on another stick, that just makes it happen sooner.

[charlie66]

Originally Posted by JLMounce

I was definitely looking in to a reverse pattern cam. I'm going to get a few opinions of course. If I can meet my goal without spending $350.00 on another stick, that just makes it happen sooner.

If you go with a flat tappet you can get one for around 200.00. But you will be limited with a boost level of around 15 psi maybe 18 psi, because of the limitations in the spring pressure capabilities of the flat tappet cam . If you go roller you can do what you want with boost pressure but you wont be able to get one made for 350.00 . Will be more like 385.00 to 460.00 depending on who you go to. But ill tell you this cam will work really well. If you need phone numbers for getting one done let me know. ill PM them to you...

Good luck....

[JLMounce]

Originally Posted by charlie66

If you go with a flat tappet you can get one for around 200.00. But you will be limited with a boost level of around 15 psi maybe 18 psi, because of the limitations in the spring pressure capabilities of the flat tappet cam . If you go roller you can do what you want with boost pressure but you wont be able to get one made for 350.00 . Will be more like 385.00 to 460.00 depending on who you go to. But ill tell you this cam will work really well. If you need phone numbers for getting one done let me know. ill PM them to you...

Good luck....

I've already got a full roller valvetrain, so I'd stick with a roller cam as I already have the everything for that conversion.

My current stick uses the comp XFI lobes.