HansB

This is correct. You do not loose boost as such, you hit the overboost protection. Different KLR/DME chips fix this.

If you have a LR wastegate, you only a MBC, and youn can loose the Cycling valve if you want. This valve modulates the boost perssure and makes it "roll on" When deleted, the boost will definitly hit harder.

Lindsey can supply you with the necesary vacuum line diagrams. This is also a good time to change all the vacuum lines with their kit.

When using a MBC, you must use an aftermarket boost gauge, at the risk of blowing a head gasket. MBC adjustment is very sensitive, one turn is 1.5 PSI, so makes the difference between optimal power and a blown headgasket.

The raise of the rev limiter is a useless function. On a stock, and even on a modified engine the torque curve is such that you have to change gears between 5600 - 6000 rpm anyway for max performance.

jbscreens

Hans

Thanks for reminding me, I also have the vac/boost guage as well.

Porshhh951
If I disconnect the alledged enhancer do I connect the rubber hoses back together right? I was unclear with your sollution.

jbscreens

The vac/ boost guage will be installed tomorrow with all the other goodies.

jbscreens

I feel confident I will have this boost problem solved thanks to you guys. Thanks.
But can I run these welt. chips with no cat? and to shim or not to shim?

rhesus

any way to get a picture of the boost enhancer?

porshhhh951

You can reconnect the rubber hoses.CV being bypassed you do not need any of that. Your manual boost controller hooked up to your wastegate will be how you modulate boost pressure. So just get rid of it completely. You no longer need it.

If you have the proper aftermarket gauge's then your set. Someone mentioning vac line's is a pretty big deal. If you aren't getting desired boost it's very possible you have a vac. leak. What's your idle H.G. readout on your vac/boost gauge. Normally anthing above 17-18 is good H.G. If you are less than that then you might have some sortof vacum leak. Lindsey does sell a great kit. I have it on my car and have had no leaks of anything to date.

Jeremy Himsel

The welt chips really aren't that bad. They're actually a fairly safe chip that won't rub you on the ragged edge like some other's. Yes, you can run them with no shim and no cat. You won't do any damage. I think the statement about the cat you read could be related to an slight increase in boost and decrease in spool-up that is seen when you remove the cat. Just a CYA by the manufacturer. If you are running a MBC, and a boost enhancer, remove the boost enhancer as suggested earlier in the thread.

Peckster

Sounds like a Lindsey boost enhancer, they have pix on their website. Your stock banjo must be installed too, not the one that comes with the chips. That's what Lindsey recommends.

black944 turbo

bypass your cv and you will be fine. My bet is that you have a blown vacume line on the cv. I was having the same problem and I bypassed the cv and all was well. But when I took my intake manifold off I found the problem. I have pics if you need them.

pk951

My Swiss was using welt chips before his upgrade at 13psi he was running rich 10 to 1 AFR on dyno. He got 240RWHP at 13psi.

The dyno was a Mustang!

turbo944

I ran the Welts in my 86 (although the package they came in was from Autothority as was the receipt....weird...) that were installed by the PO for about a year until I installed the Guru's a couple of months ago. The Guru's are definitely better, but the Welt's weren't that bad.

My car has the Lindsey dual port wastegate, didn't have a cat, no cycling valve, MBC and was running about 15psi. No running problems due to them.

Install them and your other parts and enjoy them.

facboy

i dunno, am i the only one here who is a bit uneasy with this whole thing? i think u should do a bit more reading on the forums about MBCs, chips, AFRs, and the like before you start tinkering (do a search).

i may be way off here, and don't take this the wrong way, but based on what you've written it sounds like u don't really know much about the car or how it all hangs together. lots of guys have replied with good advice, but none of it is really giving u the big picture (ie bypass the CV and get rid of the boost enhancer doesn't really tell you much about what either of them do, and why you would want to remove them).

i would get someone knowledgeable to have a look at your car, tell you exactly what you've got and how it's set up, and proceed from there.

btw i'm a total newbie as well. if i'm way off base here, i apologise, but if i'm right, i'd hate to see you get a hefty repair bill because of a couple of seemingly minor mods.

Jaak Lepson

I'v got myswiss' old welt chips and I have no problems with them!!

I do have a LBE + the chips and the car keeps chirping the rear tires in 1st and 2nd gears under boost!

I did have all the vacuum hoses replaced, a few exhaust gaskets replaced, O rings on injectors replaced, had the intake manifold glued to the heads with same sealant as the 911 heads, teracleaned the fuel system and other basic routine maintenence items done. There has been no other performance enhancments done to the engine.

This car does move. Oh, and I had the cycling valve replaced as it was cracked.

This may help you:





Jaak Lepson

jbscreens

I checked lindsey's site and confirmed that, yes it is thier boost enhancer. When I dropped off the car to the mechanic this mourning I told him about this. He confirmed with me that they disconnected the BE. It's still in place and actually connected to the hoses. He showed me farther down the line were they disconnected it and plugged to prevent vac leak. I'm gonna have him double check it though. Doesn't seem right. I'll also have them most likely bypass the CV too.

Ben Z.

I think facboy's post has some good advice that you really should consider taking.