[Adam W]

I'm dead set on using a methanol kit to run very high boost (26-30psi I guess) on my setup (been limited to around 16psi so far as race fuel is so expensive here). Probably using the PHR ECU, maybe the AEM if that doesn't work out like I hope it will. I've been thinking about weak points in my current setup.

1) Blow off valve: Currently using a TurboXS Type H-RFL. No problems so far, but I can see it being blown open at high boost, it just sues a spring to hold itself closed. Is there a unit which is proven to work reliably at 30psi? Will I need to switch to using two BOV's?

2) Valve springs: Head is all stock, valve springs have 150k miles on them. Are the intake valves going to get blown open by the boost pressure? I have no plans to raise the rev limit.

3) Clutch: Currently using the Clutchmastsers stage 3 full face kevlar unit. Can anyone tell me what the max bhp/torque handling capacity of this unit is? Anyone used it and "overpowered" it with a high boost, big turbo setup? The car isn't being built for the strip, but I want it to be able to stand up to a few runs a year, probably on street tyres but maybe on Nitto dr's.

4) Ignition: Currently using stock everythin except for magnecor leads and NGK grade 7 copper plugs (one grade cooler than standard). I think it would be worth switching to a colder plug, but is there enough spark energy using the stock setup or does it need looking at?

If anyone has any input on these, or can think of any other issues I might run into, then shout out; your input is much appreciated as always

 

[Woooossshhh]

as far as the bov goes... i donno how the rfl will last but if you want to be sure get an hks ssqv... it is designed so it cant leak...

 

[Trent]

Most BOV's are designed to hold up to about 25psi. You could go with a Greddy Type R or a HKS Racing Type 2 and either of those would hold 30 psi easily. If you wanted something smaller, you would have to go with two of them.

 

[hawkeye]

The stage 3 should be good for around 500 hp.

 

[X-man]

The TurboXS valve is supposed to be able to hold better than 30 psi, it not only has the spring holding it shut but the boost psi coming in from the line to the top of it also helps to keep it shut. The guy from TurboXS told me that they had tested it on cars running high boost and well over 650 rwhp. I made one pass the other night at 25 psi and the valve held fine with the SP67. The valves being blown open is something I've wondered about myself. Mine only have 25,000 on them, but who know's at higher boost levels. I think Will is still on the stock ignition so I don't think that will be a problem. I have a Greddy type R on the shelf and it is way to stout to be of any use at street level boost psi. Dr.J ran into surge issues with something similiar on his car. The clutch will be interesting though, I'm still waiting to see if my Spec stage III will hold. When the boost controller came unhooked the other night my clutch tried to slip alittle, but I only have 100 miles of city driving on it. It holds up to 20 psi just fine, but I only have a 20 psi gauge so I don't really no what it did the other night but it pegged the gauge hard.

 

[Adam W]

Thanks X-man. I have access to a tensile test machine at work which I could check the spring pressures on at different displacements, so I may well dig out the spring specs and make sure mine aren't fatigued or anything while the head is in pieces. I beleive the Spec sg 3 is equivalent to a CM stg 4, ie a paddle clutch, so a bit tougher than what I have now.

Do you have any dyno numbers or time slips for your 67 setup? I would love to hear how you're getting along with it, I haven't run mine for ages and even then I only saw 10 psi! Whats it like when you run it in anger?

 

[X-man]

Well the 20 plus psi goof was awesome, after I made sure the car was okay. Absolutely zero detonation, thanks to a safe tuning baseline from Will N. to get the car up and running. The rear end of the car started on around as boost psi came up, note to self, make sure the car is pointed straight and hold on. 13 psi is where I've been running it with a few 18 psi blasts and it is a completely different car then it was when I took it apart. I was worried about running a bigger turbo on the street but now I wouldn't have it any other way. I will be dynoing soon when I finish breaking the clutch in. I'm supposed to give it 400 city miles but who know's. We put them in commercial vehicles every day with 1850 ft/lbs rating on them and take them out and hook 40,000 lbs to them and go up the road and they last 700,000 miles if the centers don't break. Those don't even get the flywheels surfaced most of the time.

 

[MRSUPRA]

The Greddy type R BOV works fine at low boost. I was using mine at 10psi for a while. I did notice some surge when letting off the gas at hyway speeds, but it went away over time for some reason.

 

[Racerstud2004]

i thought the line coming off the turbo xs was a vacuum line, not a line that holds boodt to keep it closed under high boost. Somebody correct me? wo

 

[aljordan]

i thought the line coming off the turbo xs was a vacuum line, not a line that holds boodt to keep it closed under high boost. Somebody correct me? wo

Is this your car in the avitar???

 

[X-man]

Running around at cruise speeds or at idle it is a vacuum line, that is the one of the reasons you shim the spring to make sure it has enough pressure to be closed at idle. The other is so that it doesn't open when you first come under boost. After you build positive pressure or boost the vacuum lines have boost psi on them.

 

[SupraMkiii24]

Is this your car in the avitar???

No, that is not his car, in the avator. He replied in another post somewhere, that his car is torn apart and that this car resembles his closly. so he is using it for the time being. He also stated he's going to change it as soon as he gets pics of his ride.

 

[Racerstud2004]

No, that is not his car, in the avator. He replied in another post somewhere, that his car is torn apart and that this car resembles his closly. so he is using it for the time being. He also stated he's going to change it as soon as he gets pics of his ride.

yeah, what he said

 

[turbotoy]

I'm dead set on using a methanol kit to run very high boost (26-30psi I guess) on my setup (been limited to around 16psi so far as race fuel is so expensive here). Probably using the PHR ECU, maybe the AEM if that doesn't work out like I hope it will. I've been thinking about weak points in my current setup.

1) Blow off valve: Currently using a TurboXS Type H-RFL. No problems so far, but I can see it being blown open at high boost, it just sues a spring to hold itself closed. Is there a unit which is proven to work reliably at 30psi? Will I need to switch to using two BOV's?

Two blow off valves will not help anything if they are releasing due to insufficient spring force, they would just present less backpressure.

2) Valve springs: Head is all stock, valve springs have 150k miles on them. Are the intake valves going to get blown open by the boost pressure? I have no plans to raise the rev limit.

Not an issue. The frontal area of the valve is small enough you would only be applying ~25 lbf max. Besides, the only time there isn't pressure in the combustion chamber when the intake valve is open is during the exhaust stroke.

 

[X-man]

Not an issue. The frontal area of the valve is small enough you would only be applying ~25 lbf max. Besides, the only time there isn't pressure in the combustion chamber when the intake valve is open is during the exhaust stroke.

Good point.

 

[Adam W]

Something else I've thought of. I'm currently using ARP headbolts, I torqued them down to 65ft/lbs on my old setup and they held up fine at 17psi on my 60 trim CT26. Will I be OK sticking with the bolts and crancking them up to about 90ft/lbs, or shoul I switch to using studs?