300whp 951 on a budget

[Fast951]

I'm using a ball & spring MBC upstream of a "black knob" MBC... the two in combination seem to work very well!

The ball & spring gives initial quick boost build

The black knob is a safety preventing any ball & spring spikes and overboost (I understand that B&S can spike dangerously)

A proper ball & spring MBC with a ceramic ball should function fine by itself. Have experienced spikes yourself? If so, would you share some information, pictures of the B&S MBc you have?

As far as over boosting, any MBc will over boost or under boost. If you set boost while the outside temps are warm (ex. 80F), if temps drop (ex. 35F) then a billed type or a B&S MBC will over boost. The opposite in temps variations will underboost.

The solution is a closed loop EBC, but that's more $.

Just to clarify, in case someone is not aware.
A B&S MBC is to be used with the stock single port WG, it does not work well with the dual port WG.
A bleeder type MBC is to best suited for dual port WG. It can be used on a single port WG, but does not offer best performance.

The bleeder type MBC is a mini pressure regulator as the one used on air compressors. In a pinch, you can pick one up at a hardware store. Not all bleeder types MBCs are the same, there is the build quality, precise control and flow characteristics. There are good ones for $20-30.

[Fast951]

You can use the Bosch 3 Bar FPR with the stock fuel rail. Looks just like the factory one. That's what I use.

Fast951 sells turbos -- or at least he used to -- he's Vitesse Racing. His Stage 2 turbo would be perfect for your goals, but I'm not sure if he still sells them.

The Bosch 3bar FPR is the way to go, but prices have gone up greatly. There are alternatives. An adjustable FPR is another option.

For the time being, I'm not offering any turbos. Parts availability has been an issue. Yet to see it fully recover.

[danmartinic]

A proper ball & spring MBC with a ceramic ball should function fine by itself. Have experienced spikes yourself?

No, I haven't experienced any spikes.. though I've read about this issue quite often. I guess I'm just over cautious. Thanks for the extra info regarding temps and differences between the control types

Sometimes I wish I kept the stock system. If I understand correctly, it's already an EBC and has the added benefit of being factory with knock-control (boost cut) via the KLR

I am a little surprised no one has made a chip or mod for the stock system to increase boost yet keep all the saftey in place..?

[Fast951]

Sometimes I wish I kept the stock system. If I understand correctly, it's already an EBC and has the added benefit of being factory with knock-control (boost cut) via the KLR

I am a little surprised no one has made a chip or mod for the stock system to increase boost yet keep all the saftey in place..?

Making a chip to target a certain boost is doable. However, it will be fixed, and not user adjustable.

A possible approach that provides flexibility and keeps the KLR as a EBC, would be by altering the boost feedback signal that the KLR relies on. Use a bleeder type MBC on the pressure line feeding the KLR.

By bleeding the pressure signal before it reaches the KLR, you are tricking the KLR into reading lower boost than actual. In return, the KLR tries to hit its target boost (by raising boost). So you are able to run higher boost than the KLR chip was programmed to target.

The actual KLR target overboost has been raised, but still there.

Of course be careful and proceed at your own risk!!!!!!

[Tom]

Sometimes I wish I kept the stock system. If I understand correctly, it's already an EBC and has the added benefit of being factory with knock-control (boost cut) via the KLR

I am a little surprised no one has made a chip or mod for the stock system to increase boost yet keep all the saftey in place..?

Making a chip to target a certain boost is doable. However, it will be fixed, and not user adjustable.

A possible approach that provides flexibility and keeps the KLR as a EBC, would be by altering the boost feedback signal that the KLR relies on. Use a bleeder type MBC on the pressure line feeding the KLR.

By bleeding the pressure signal before it reaches the KLR, you are tricking the KLR into reading lower boost than actual. In return, the KLR tries to hit its target boost (by raising boost). So you are able to run higher boost than the KLR chip was programmed to target.

The actual KLR target overboost has been raised, but still there.

Wouldn't the DME 'overboost' protection (over-load protection) kick in anyway?
Of course be careful and proceed at your own risk!!!!!!

[Fast951]

Wouldn't the DME 'overboost' protection (over-load protection) kick in anyway?
Of course be careful and proceed at your own risk!!!!!!

I would assume, anytime boost is adjusted away from stock, the DME chip has been modified to support the new boost curve.
A performance chip must address the overboost/overload protection in the DME.

Actually, you do not need to alter the boost curve to trigger overload in the DME. Enhance the engine VE (better flowing head, free flowing exhaust) and you can trigger overload even with a stock boost curve. Overload is based on air flow, RPM and time.

One must look at the DME/KLR as a system.

In my earlier post, I should have been more clear. The KLR will be able to still control or limit boost (vs. saying overboost).

[stitch2k1]

You can use the Bosch 3 Bar FPR with the stock fuel rail. Looks just like the factory one. That's what I use.

This? https://www.paragon-products.com/Porsch ... 11.541.htm

Fast951 sells turbos -- or at least he used to -- he's Vitesse Racing. His Stage 2 turbo would be perfect for your goals, but I'm not sure if he still sells them.

Oh good to know, he should add that to his signature :p
I would love a MAF kit...but that's not happening today.

Are you keeping the AFM and just adding a cold air snorkel to replace the black plastic from the factory?

Not going to use the stock air box whatsoever, I do not want to pay for one. Just going to run piping from the AFM to grab air from down in the fender, hopefully find a way to get some ram air without sucking up rain water. I might just opt for a lazy filter right where the air box is just to get the car driving. Once it runs I can iron the kinks out..

As far as over boosting, any MBc will over boost or under boost. If you set boost while the outside temps are warm (ex. 80F), if temps drop (ex. 35F) then a billed type or a B&S MBC will over boost. The opposite in temps variations will underboost.

Luckily I am in Florida, where temperature is pretty consistent once the summer rolls in. But that's easy enough to keep an eye on.

The solution is a closed loop EBC, but that's more $.

Electronic boost controller would be nice. What would you recommend other than just ditching Motronic for standalone?

Just to clarify, in case someone is not aware.
A B&S MBC is to be used with the stock single port WG, it does not work well with the dual port WG.
A bleeder type MBC is to best suited for dual port WG. It can be used on a single port WG, but does not offer best performance.

Thanks, that's news to me. I have a stock 951 wastegate, and I plan to use that for now. That's single port correct?

A possible approach that provides flexibility and keeps the KLR as a EBC, would be by altering the boost feedback signal that the KLR relies on. Use a bleeder type MBC on the pressure line feeding the KLR.

By bleeding the pressure signal before it reaches the KLR, you are tricking the KLR into reading lower boost than actual. In return, the KLR tries to hit its target boost (by raising boost). So you are able to run higher boost than the KLR chip was programmed to target.

Stupid idea incoming. Correct me if I'm wrong:
What if you had a spring based MBC in the engine bay (for example) set to 20 psi, and a bleed based MBC on the line to the KLR set to 18 psi, and the KLR was maxed at 15 psi. You would need to monitor the pressure in the boost line to the KLR (factory gauge in the cluster), and monitor the real manifold pressure via a standalone boost gauge?

[stitch2k1]

Also adding to some earlier stuff: talking to four0four off here got me into googling HG stuff. Old forum posts, so who knows how much is right but what I saw was:
Widefires seem to necessitate an o-ring'd head to gain performance. I should check my two spare 951 heads for that. Otherwise run stock, and I happen to have a spare stock head gasket already. Maybe I ought to just pull the head* and replace it with a stock hg and use the Raceware studs. MLS also came up in these forum posts, and they said don't even try without getting the block and head decked. Sounds too expensive for this project. Still do ACL rod bearings while it's out though.

*since I still need to clear debris from the cylinders, due to the motor being stored without plugs in it.
No this doesn't concern me about the rest. I've looked over it enough to know it's good to use.

[danmartinic]

The KLR will be able to still control or limit boost (vs. saying overboost).

Doesn't the stock KLR control or limit boost via the cycling valve? The aftermarket systems don't use the CV..?

[Fast951]

The KLR will be able to still control or limit boost (vs. saying overboost).

Doesn't the stock KLR control or limit boost via the cycling valve? The aftermarket systems don't use the CV..?

You wished you "kept the stock system". It includes KLR and CV... When you install a bleeder valve at the pressure line to the KLR, you continue to use KLR and CV for boost control. You are altering the input pressure signal to the KLR in order to trick it to raise boost.

The most popular boost control methods, take away boost control from the KLR by eliminating the CV and using a EBC or MBC.

There is a way to take boost control away from the KLR but keep using the CV. An electronic boost controller is needed to control the CV (as a boost solenoid). I have done it with a piggyback controller.