Pipe dream?

[topnotch]

Looking to make close to 400hp with a stock unported stock valve head, is it do able?

My current setup

1988 notch
2.5 crank, stock rods, flat top pistons
stock iron turbo head
roller rockers an cam
ported e6
hx40 plan to goto 30psi
ported lower an upper
BIG FMIC
LA3, plan on J3 chip
big vam
stock tb, trying to go bigger
62lb injectors.

What am i looking at now with this setup and what needs changing to achieve my goal?

thanks

[Stinger]

With a stock head and cam, that HX40 is going to be a complete dog. I wouldn't expect it to do much of anything before 4000 rpm and probably won't reach full boost until 4500rpm or so. That's a problem when the stock cam only likes to rev to 5000-5200 rpm. An HY35/HE351 would be a better match. It's also going to take closer to 35psi to get there. I know of one SVO that made just over 400rwhp on a stock head and I'm almost positive boost was in the mid 30's. svojohn is the one who did it. Maybe he'll chime in.

[svojohn]

400 at the wheel or the crank? There's a big difference between the two. I agree with Stinger on the HX40 being a complete dog on a stock head/cam combo. Make sure your cylinder head has a good seal on the valve seats and use better than stock valve springs. Also I had no luck with stock head bolts at 35 psi, ARP head studs and the Felpro 1035 worked well for me.

We have an 86 SVO here that's mostly stock and it put down 326 rwhp @ 5700 RPM and still holding 324 @ 6100 RPM with 28 psi. The turbo is a Chinese T04E 50 trim which was purchased from Ebay for $150.00. At 326 rwhp the MAF peaked at 43 lbs/min of airflow which is around 390 crank hp. The car has been 89 MPH in the 1/8 mile with a 3200 lb race weight. Here's the combo: stock shortblock, stock head/cam, stock upper/lower intake, stock throttle body, ported E6, 3" downpipe, T04E 50 trim, front mount intercooler with 2.5" piping, PE with Moates chip, HPX mass air sensor, 95lb injectors, 255hp fuel pump, 38mm external wastegate, Taylor spark plug wires, NGK TR6 spark plugs gapped at 0.026, 93 pump gas and the knock sensor is still connected.

[svojohn]

FYI: For us to reach 500 crank hp with the above combo, we'll need to find a turbo that's happy at 40 psi and flow 54 lbs/min of air.

[Stinger]

Thanks Jon. What about the one that threw a rod, didn't it make just over 400rwhp before it grenaded?

[svojohn]

The one that threw a rod put down 390rwhp according to my data logs and on the dyno it put down 440rwhp. I believe the data logs to be more correct than the dyno. The MAF would peak a little over 50 lbs/min of airflow at 5500 RPM and 35 psi of boost. The reason for the engine failure was more my fault than anything else. I added a 100 shot of nitrous and took the car to the track to make a glory pass. The valve cover started leaking oil at the track so I decided to unbolt the valve cover and fix the leak. This required removing the nitrous lines and jets. In the process I accidentally dropped the fuel jet on the ground, it fell in the dirt during night time and I never recovered it. The only jet I had with me was 2 sizes bigger so I just assumed it’ll run a little on the fat side. Normally I would make the first pass without nitrous to make sure everything is good but it was getting late in the evening and the line was long so I made the first pass on nitrous. We all know the end results.

I had a few people who I believe are really good with engines to take a look at my broken engine parts. They all came to the same conclusion, it looks as if the engine had too much fuel in it during compression which caused the cylinder wall to give away first. I believe the stock shortblock will hold up well if your tune is spot on. Get careless like I did and you’ll have metal parts lying on the ground.

[Stinger]

Turned from glory run to glory hole...