zogster

So… I am about to replace the k26/6 in my '87 RHD 951 with a k26/8, and have a couple of questions about raising boost and power.

Quick background: I'm doing this because the existing turbo needs a complete rebuild right now, and it was quicker and easier to get a low-mileage k26/8 than to get this one rebuilt. Plus it allows for tuning if I want to go that way in future.

My plan is to drop in the k26/8, and replace the existing DME and KLR chips with factory chips from a later 250BHP car. So for now I'm basically just updating my '87 to a later model year spec. I may want to take things further in future, but I want to get the simple turbo replacement done and have everything running properly before I tinker further.

Question 1: that's all there is to it, right?

As far as unleashing more power goes, I'm thinking about a ProMax level 2 chipset. Now, I am not experienced in tuning and chip swapping, but I understand that the chip needs to be matched to the turbo and other components and their behaviour…

Question 2. If I install ProMax level 2 chips, do I need a dual-port waste gate, manual boost controller, and 3 bar fuel pressure regulator? Or can I achieve an intermediate level of raised tune by simply replacing the CV with a boost enhancer/controller and keeping the existing FPR and waste gate?

schip43

I run a Pro Max chip but I don't know what version?? A 89 Turbo S and to your list above if you add 55 lb injectors and a cat delete, you can run 17 lbs of boost on pump gas.

And in first gear it will smoke the tires w/o clutch dumping ... you just give it a little more gas cuz it's kinda slow from a dead stop and the next thing you know?? It lights up the rear tires??? It goes from kinda lazy to full boost in the blink of an eye?? as terrified to let my wife it for the first time! But she had no issues?? But then shes kinda slow and lazy with the throttle so just before it starts to build boost, she shifts gears. And in forth or fifth at cruising RPM ... the party is over. You gotta start dropping gears if you in a hurry. And in third gear at about 75 mph and 3200 rpm?? It will take off like it was launched from an air craft carrier!! At any rate it's a good chip but I think the AFM is responsible for the "lazy" throttle response?? The gas peddle at low speed, and low RPM act's more like an On/Off switch instead of a Rheostat??

In any case , you talk to them, tell them what you got and they'll burn the chip for you. and if your CA, it will pass smog with the chip but you gotta put the cat back on,

blade7

Promax have ceased trading, so I'm not sure you if can still buy the chips from Andy. You would need to use a 3 bar FPR and a manual boost controller with the chips. JMG Garage can supply chips etc, just make sure you speak to Jon Mitchell if you call them.

schip43

Hmm maybe I got the company wrong?? I have a "Max chip." Russell Berry" I think?? Ok I, checked it's from here.

http://www.maxhpkit.com/

blade7

I think the ProMax chips were mildly tweaked Lindsey chips, and Lindsey could have been connected to maxhp? So in a roundabout way you may not be that wrong.

zogster

Yeah, I realise that ProMax went out of business… the chips I'm thinking of are second hand. Which I guess means I need to check exactly what spec of engine they are for as they won't be burned to order.

blade7

They may have some stock left.

mtnman82

Your first step is correct - if just replacing the k26/6 with a k26/8 and not raising boost, all you need are a set of the '89 chips for your DME/KLR.

Once you want to go beyond that, Vitesse/Lindsey M-Tune/VEMS are the 3 main players at this time. These systems read your boost and keeps the tune in check - i.e. you can turn up/down the boost and you're till running an optimum tune. The MAXHPkit/Promax/etc. products are tuned for a specific boost level - they don't read the boost. If you're going to run a black **** boost controller, your boost will vary depending on temperature and/or altitude. I would recommend a boost-based tune/kit.

Edit: I believe the Promax chips also had a module which gets wired between your AFM and DME (?). If you go that route make sure you get that piece too if required.

Humboldtgrin

If you use 55 lbs low impedance injectors make sure to use 1 ohm resistors per batch if you plan on using the stock DME.

blade7

Do 89 chips fit an 87 DME? And there's no module with ProMax chips.

zogster

I think re. '89 chips in an '87 that I need to solder in 4 more pins for the later chip (or de-solder the 24-pin socket and replace with a 28-pin one), and add a jumper to the circuit board - pretty straightforward.

schip43

Yep ... 17 psi at altitude 4000 some odd feet in Dayton NV equals 21 psi at sea level, San Jose Ca. It can do that, 21 psi but not suppose to on 91 octane. I blew off the J boot mid trip, in the middle of the night!! So I couldn't boost at all. But it limped along the rest of the 150 mile trip. We fixed it (for the most part) the next day and took it out, after warm we hit the freeway and I nailed it. I was like holly $hit! And my friend riding shot gun ... quickly dialed it down! No harm no foul.

I think your spot on with your recommendations, it seems .... silly to me use some random chip that may or may not introduce "issues??" The chip for my car was burned for it and my friend reports he had to have two other burned before this one. The Op won't have that support??

The MAXHP chip is still available from the company or LR the Rough/LR AFM chip kit would "most likely" provide better "off boost" drivability?? I find low rpm off boost throttle response, kinda slow and lazy?? But my friend most likely did not care?? The chip was burned for him and how he drove so I don't know if it's the chip or the limits of the AFM at low speed/rpm?? The Vitesse, option is also a very good option ( at more upfront cost admittedly ) as among other things one can ditch the AFM ( that may or may not be my issue??) but the tuning issues have already been solved!



.

zogster

This whole turbo upgrade thing is quite the rabbit hole…

From user comments I can believe that the Vitesse products are first-rate… I may have to drop the fella a line. Though I have also just bought pre-owned ProMax chips (£80, seemed too cheap to pass up)

My normal driving doesn't cover much range altitude-wise (not too many mountains in southern England), but I take the point about gas laws, boost, and temperature/altitude

schip43

£80 ... you already got it?? Well count that as a "cheap lesson leaned" or perhaps "issues" avoided??

Times have changed and there are better "options" available, although even the least expensive are gonna cost more than that??? But you know ... do you want to drive your car or "trouble shoot it "with no support??" How much is your time worth??? Cuz right now that is the "rabbit hole" your getting ready to go down??

You have better options available for not much more that "questionable" for you car chip cost. An actual, http://www.maxhpkit chip for your car is $345 and a Vitesse, chip (I did not know he still chips??) is about the same. Most likely supporting mods still required but you'd know what they are and you'd have "support!"

And I can say as far as sheer hp and torque go?? LOL, my Max chipped 89 Turbo S, could beat down a stock Turbo S like a wet dog!! Freaking insane, it does quite well, thank you very much! But day in day out in ... it's just not very "civil??" The throttle is an off/on switch?? It's just slow, off idle and if you get impatient and give it a quarter inch or so more throttle??? It say's OK ... time to get busy and 15 psi (I'd dialed it down) making a left turn??? Back end goes up in smoke and full power slide from a light making a left turn, WTH??? More than a couple times ... I got lucky there were no cops nearby! Tools tend to "tick me off!" And if I nail it, it answers hard and fast!

I blame the AFM but I don't know?? Maybe my friend ... did not care?? So he had the chip tailored for him. Off boost performance just kinda sucks but I never drove a Turbo S, so I don't know?? But back on point, the Rough AFM, kit might be better?? But apparently "Rough" is no longer involved with his product?? That's not good "if" you have "issues??" So for a chip, I'd go with a "maxph" chip, straight from them, but sadly, Russell Berry, has passed on.

So I don't know what that means for his company and support of his products?? So that leaves Vitesse, as the last man standing for chips. And he is still here and I've heard no complaints about service or products!

But wait ... there's more! If you want to ditch the AFM, which may or may not be an issue as regards civility?? There is this ...
http://www.vitesseracing.com/html/95..._air_flow.html

If you feel your thirty old wiring harness and those freaking reference sensors are still good to, there you go! A full plug and play solution also with a bit more work admittedly! But it's not that much more the Vitess Maf kit. But the old engine harness can be gone if you want??? But if you want to keep it and hope for the best it can be gotten as a plug and play! Pull the DME out and put the VEMS in and there you go.

We have a thread here on that one. : https://rennlist.com/forums/944-turb...s-install.html

I'm thinking about pulling the trigger on that one myself as I have another car that "needs" a standalone but while not an issue for you?? Most likely, I don't like the Metric gauge display, but hey that's just me?? At any rate as I train my dogs to do ... "Make good choices!"

968to986

You raise a lot of questions??
I'm actually upgrading my 87 951 to K26-8 as well and I am seriously considering the A-Tune offered by Lindsey Racing. I already had their Max chips with the K26-6, which was quite effective with Tial, 3.0 FPR and MBC. https://www.lindseyracing.com/LR/Par...IP-A-TUNE.html