How much HP adding a K27 and headers

[Oh Haha]

wcc, hope you don't mind but I am curious.


We will be installing a full GHL header system and a K27 to Bill's 87 930 this weekend. The car was fast already just mostly stock.

What kind of HP gain may be possible with this upgrade. I think he has an .8 bar boost spring it and that,will remain, I think.

Thanks,

[wcc]

I don't mind. I have a .7, .8 and a 1.0 BAR spring. Currently, I have the 1.0 BAR installed. So it was very quick. But to answer your question, this car after these mods will be FAST! (waving back)

I'm curious as well.........

[spuggy]

I picked up 85 FWHP and 60-odd ft/lbs of torque with a K27/HF, GHL's and a Kokeln with a Brian Leaske adjustable WUR, boosting to 12.5 PSI on a VDO gauge (although as far as I know it's a factory spring in both wastegates).

It may depend on the model of K27 what difference it makes - and you might not get quite as much with stock cams - it makes peak power @ 6100 with that configuration and SC cams. I also went from an open muffer on the first run to a factory RoW muffler (still with a separate wastegate dump pipe), which apparently costs me 10-15 HP.

[RarlyL8]

The '87 has the best (Euro style) stock heat exchangers.
The headers will do more for driveability and spool time than actual HP.
I'd say with a stock engine that headers and a K27-7200 has the potential of ~50HP to the wheels. I say potential because if you leave the stock cat/muffler on it will not be realized.
You will have less of an off/on transition to boost which will add to the experience.

[WERK I]

If you really want to wake the engine up, a cam change is in order. Even a mild SC grind does wonders in improving the breathing of the engine. Keep the '87 heat exchangers, upgrade the turbo and cams. You won't regret it.....best bang for the bucks.

[fredmeister]

So how much restriction do you think the stock muffler really makes?

[carmad]

I have stock headers, K27-7200, SC cams, B&B intercooler,1 bar Tial wastegate and GHL dual outlet muffler.
Dynoed at 365 Hp and 400 ft/lbs at the wheels.

[RarlyL8]

The stock muffler takes away 12-15HP according to my dyno results on a 300WHP 930 engine.

Julian, your numbers are in line with what I have seen with that setup when going from 0.7bar to 1.0bar boost. The SC cams are good for ~20HP over stock but change the dynamics and torque by much more.

Bill, I would expect your stock engine with headers and K27-7200 to be ~300WHP @ 0.8bar.

[equality72521]

Originally Posted by RarlyL8

The SC cams are good for ~20HP over stock but change the dynamics and torque by much more.

In a good way or a bad way?

[Darkhorse]

A K27, headers and a 1 bar spring took me to 370 FWHP.

[wcc]

This is great stuff guys! Thanks! Yup, new cams are on my list one day. Not in my recent project though. I do have the GHL muffler as well and I made a straight pipe. I'm not sure which one is gonna end up on the car yet. I thought I'd leave the 1BAR spring in there, but again that is a burning question. I may put the .8 in for longevity. We'll see....

[Oh Haha]

Bill
We HAVE to try the Zork out if we get her running Friday!!!! hehehehehehe

[RarlyL8]

In a good way or a bad way?

In a good way. The SC cams give the engine more low end torque. My 930 engine feels stronger off boost than the SC engine that preceeded it did below 3K rpm.

[wcc]

Originally Posted by Oh Haha

Bill
We HAVE to try the Zork out if we get her running Friday!!!! hehehehehehe

Sure! Hopefully we have enough time to try a couple of different things AND have time for some Hooter's Wings......

[carmad]

Here are my numbers.

[WERK I]

Originally Posted by equality72521

In a good way or a bad way?

In a very good way.

[Craig 930 RS]

I'd second what Brian said:

I'd say with a stock engine that headers and a K27-7200 has the potential of ~50HP to the wheels.

[equality72521]

Ok, so I nead headers now. I have my new K27-7200, TiAL 46mm wastegate, tensioner upgrade kit, LC1+ AFR kit, free flowing exhaust, and a few other odds and ends. I already have a Euro car so I should have a nice upgrade.

Is it simply shorter tubes that make the headers better than OEM Euro HE's?

[RarlyL8]

You won't see that much difference in power by adding headers if you already have Euro HEs and a K27-7200.

The difference is the design and flow, not the length of the tubes. Tube length affects torque placement and to a lesser degree, spool time. Look at the tube path on the Euro as compared to a set of early N/A exchangers or any aftermarket header. The unequal long lenths dumping into a long J-pipe are not optimal. The US version is an even worse design and more restrictive.

[equality72521]

I see. So I would be (slightly) better off spending my money elsewhere. Thanks for the info.