Evan70

Ok, I was digging around my new (to me) 951 S today, and discovered a Lindsey Racing dual port wastegate. I had already found the manual boost controller in the glovebox (again Lindsey Racing). Any advice on this setup. From what I can find doing a search, their seems to be a big debate about whether the MBC is really as good as an EBC. There isn't an aftermarket boost gauge, so all I can go by is the stock gauge, but it seems to hold boost well (same gauge postion) in all gears and doesn't seem to fall off at higher rpms.

It also seems to spool up fairly quickly (about the same as I remember my 86 951 with LBE) doing, but I could be wrong (it's been a few years). Boost seems to come on really strong right at 3000 rpm.

Aslo, I did notice once that I may have gotten into overboost protection (seemed to momentarily loose all power at about 4000 rpm on one WOT run). But it's only done it the one time. I believe the car has the stock chips, but I'm not positive on that. Is there an easy way to check?

Also, the car came with what are supposedly Authothority Stage II chips for an 88 951 S. Is there any way to look at the chips and tell for sure? If there are the right chips, would they be worth putting in with this setup?

DDP

First, welcome to rennlist. Second, get a boost gauge to start with just to be sure. I dont know anything about the autothority chips for the S cars but I do know for the reg turbos they had a a/f ratio problem. Too rich in the low end and too lean in the high end. But again that was for a non S car. I think, but am not sure if the lindsey controller is setup as a dual port mode. An EBC is always better to hold the boost to redline but will take a bit longer on spool up, this difference is most likely NOT noticeable. Because you have an S you will have the #8 hotside and your turbo will hold boost until redline much better than a non S. To check the chips you need to remove the DME computer in the passenger foot area. Pull the carpet back and you will see the 2 computers, the DME and KLR, in the foot place on the pass side. You need to get them out, open up the DME unit and check the chip. To see exactly how to do this, check out www.clarks-garage.com. There are some great write-ups there. If I were you, just knowing autothoritys non S chips, I would dumb those and get a real set from one of our vendors here. Search for which vendor you like best. But back to my second statement, get a boost gauge pronto! And good luck!

Evan70

Yeah, a boost gauge is right at the top of my list along with getting all the maintenance done on the car (belts, waterpump, etc).

RPG951S

Hi Even70

Couple of things. Why aren't you 'sure' that these are Autothority chips? Do they not have stickers on them? (should say something like: Autothority Performance Eng. Copyright XXXXX, POR.01.951.320.DME/ POR.01.951.320.KLR.) The DME chips should have 28 pins/24 for the KLR chip.

The AA chips are fine at 15psi, but you must use the jetted Banjo-bolt that came with the kit (it may be already installed on your car). Using a manual controller is asking for trouble, the chips expect a falling boost curve at high-rpm. Get a real boost gauge right away!

You will definately gain some power with the 'newer' aftermarket chips, but the AA chips have been in use for years(with thousands sold) with no real issues.
I'd stay away from hammering the car until you figure out which type of chips you have.

A manual boost controller with a good wastegate is the BEST boost control setup available. EBC's will be 'slightly' better, but I don't think they're worth the extra cost, (not to mention the complexity and reliability.)

pk951

With my AA chips i was running very rich in mid range 9.1, at 6000 plus 13.0 i used them for a few years, for the street you should not have any problems. At first they were used with CV then i installed MBC set at 15 PSI still have the same HG.

Evan70

Ok, just got off the phone with Autothority and they are the proper chips. There recommendation was leave the wastegate on the car, but remove the manual boost controller when adding the chips. Any thoughts on this?

PCinDC

They recommend that because those chips are not optimized for use with boost pressure above the 15PSI they are mapped for. The jetted banjo bolt IS your MBC if you plan on retaining the AA chips.

If you want to run more than 15 PSI, get a different set of chips. You already have the DP wastegate and the boost controller so I would think this would be preferable.

Question for everyone else: Would he need to revert to a stock banjo bolt?

HTH

Evan70

Guess maybe I'll just sell the Autothority chips/bolt and keep the existing setup. Once I get all the maintenance done, then I'll start looking at what performance mods to get.

Anybody want a set of Autothority Turbo S chips and banjo bolt? What's a good asking price for them?

facboy

yes he would need to go back to the stock banjo bolt, unless he got a set of chips specifically mapped to his car (which would then take the effect of the AA banjo bolt into account). but the AA banjo bolt is prolly just going to interfere with the operation of the MBC anyway, and there's no benefit to keeping it there anyway, so i'd just take it off.

Evan70

I'm pretty sure it's still the stock banjo bolt on the car right now. The Autothority chips and bolt are still in a bag waiting to be sold at this point.

special tool

WAIT A MINUTE - the APE chips are in a bag??? And you are stumbling at 4000?
I am going to assume, therefore , that the APE JETTED bolt is still in the car, and your STOCK chips (that are also in the car) do NOT like the APE jet.
Look at the bolt in the bag, and see if there is anything inside it to restrict flow - post a picture if you can.

APE chips + stock bolt = SLOWER than stock, too rich
STOCK chips + APE bolt = overboost protection