How much HP adding a K27 and headers
 

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,SmileWavy

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! SmileWavy (waving back)

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

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.

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.

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. :)

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

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.

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.

In a good way or a bad way?

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

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....

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

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.

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

Here are my numbers.http://forums.pelicanparts.com/uploa...1205888783.jpg http://forums.pelicanparts.com/uploa...1205888838.jpg

In a very good way. :D

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.

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?

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.

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