lsnapcasel

Ok, I've been searching but can't find any info on these turbos. First, I know they're both the k26, but how much boost do they run stock? How about what's their max? Anyone know the specs on either? Any help greatly appreciated.

cuatrokoop

I actually just emailed BorgWarner's turbo division (aka Kuhnle, Kopp & Kausch) about trying to get more info on the K26 my '86 uses (flow rates, efficiency, etc).

Factory boost was 0.5bar, +/- 0.1bar. Boost usually goes up to 1-1.2bar after chipping (going from memory, so those that have chipped want to chime in here?). Probably somewhere around 300hp in stock trim. If you can get a hold of a K27 or larger, you can make a factory motorsport type hybrid.

www.turbodriven.com is BW's 3-K site.

SteveAngry

Factory boost was:

MC1 Engine with MAC11 ECU:
1.42 bar absolute(6.1psi of boost)
MC2 Engine 1.39 with MAC14 ECU:
1.39 bar absolute(5.6 psi of boost)

With your basic chip, boost is usually increased to 1.8 bar absolute(11.6 psi)with some chips giving up to 1.9 of overboost for a few seconds...

The chip also changes the fuel map and moves the overboost fuel cutoff from 1.7 bar to 1.95 bar...

A 1.8 bar chip/spring setup usually equates to 220-230 hp. Of course that all depends on who's chip you're using as they have different characteristics...

The K26 has 3-4 different combinations of compressors and turbines. These can be combined together to make a hybrid K26 with lot's of flow over the stock K26.

The K26's hotside can also be mated to a TO4E or a T3 cold side to make a hybrid that way. It will require some modifiactions to the water/oil lines. The straight K27 turbo is a little to big for our displacement cars and meant for 3.0 liter+ cars.

Majestic Turbo, 2bennett and some others do make hybrid K27/K26 turbos...

Steve
Michigan

lsnapcasel

I thought that 1bar was equal to about 14.7 Psi. Am I wrong on that? If not that would make the max boost about 20 psi. So basically the K26 is efficient until 1.95bar?

cuatrokoop

No no...There are two different ways to measure pressure. One is "absolute" which is atmosphere + the added pressure. Subtract atmosphereic to get the actual pressure.

The other type is "gauge", which only indicates the actual pressure, with no input from the atmosphere.

1.5 bar "absolute" is equivelant to 0.5 bar "gauge," assuming that ATM is 1 bar. Around here, the absolute measurement is 0.9-1.0 bar, so my car was making 0.4-0.5 bar of boost.

shortyq

Turbocharger maps are rated as Pressure Ratio on the x axis, flow on the y. Pressure Ratio = boost pressure + ambient pressure/boost pressure. The stock k26 from 1986-1989.5 are all the same, and are good for 2.2PR maximum. That's roughly 18psi at sea level.

With stock type 44 with "2bar chip", maximum HP at 2.0bar is more in the 220 range, not the 300 range. The biggest restriction to HP on early type 44 cars is 1) fuel, 2)IC restriction. Solve 1, you run into 2. Solve both, you can get about 300hp peak (not continuous) out of the stock turbo.

HTH

Scott Justusson
QSHIPQ Performance Tuning
2.5bar type 44tqw