I got my Turbo Last night!

[GO DAWG GO]

I received my k27HFS (HiFlow) turbo from Imagine auto last night. It looks well
made. Talking to Stephan yesterday ordering a B&B Intercooler. He said that the K27HFS may not provide the same low end torque that the K27S might provide. I didn't want to ask too many questions because he is a busy guy and I don't want to be a nag. Anyway- So far I have a K27HFS and a B & B intercooler. I have heard most people say the turbo may be overkill for my stock motor but wont necessarily be a problem. I plan in the future to do a top end job and replace the cams and get some head work done.

Nathan has said repeatedly that this was the one I should get.

"The best KKK turbo to get using CIS/K-jet is the K27HFS from www.imagineauto.com Good spool up and high bhp." -Nathan

Question: can I run my stock headers and wastegate with the K27HFS with a 1 bar spring. Do I need to spend the money now on a header system and WG?

I have a fabspeed exhaust on the car now!

Will the stock waistegate overboost my engine?

What kind of throttle response will I get with this. will it come on at 2600 with the stock headers. Please tell me your thoughts and experiences.


Thanks

Bob

[RarlyL8]

You should know the answers to all of those questions before buying the turbo. You're not being a nag when you open your wallet for $1500+ he will answer your questions.

If you want to use your stock equipment the HFS is overkill. Even with head work cams and headers the K27S is a better turbo for the street. To see the difference you have to use both turbos on exactly the same engine.

[GaryR]

Yep, cart before the horse unfortunately.. I put headers, K27 7200, Tial WG with (for now) .6 bar spring, and Fabspeed on my car after asking a TON of questions here and elsewhere. I couldn't be more pleased with my cars linear performance. Virtually no lag, and gobs of power (for me) throughout the RPM range all the way to redline. This turbo also put out 1.2 bar (stock WG w/1 bar spring) and held it without an issue so I know she has plenty to give. Still stock I/C but that could change as soon as I trust one of the aftermarket guys enough... Getting a G50 installed this week w/ Hargett shifter, can't wait to get her back!

[GO DAWG GO]

Brian,

This is my greatest dilemma because these are the answers I keep getting. "Overkill" in my opinion that doesn't mean it wont work! You can kill a jack rabbit with a 30 06. Thats what I call overkill. What does overkill mean? (Redundancy) (Superfluous) Does that mean it will act like a super high lift cam and provide only high RPM's and no low end torque. What does better for the street mean? Smoother response? Stephan said it would work with raised eyebrows in the tone of this voice. I just want to know in definition what that means. Is it going to be a Bucking Bronco per se? Will the stock wastegate control the charge? Please explain:

Bob

[hobieboy]

My 2 cents... you need to change out your headers.

It doesn't matter how big/good your turbo is if the supply chain (header) can't flow enough or fast enough.

Turbo is always a compromise - I think the HFS is designed to flow a lot; hence you need the head work & header. And to take advantage of all that air flow, you need to find a way to supply correct amount of air and ignite them at the right time to get the benefits. Otherwise, you'll end up getting less than what a smaller turbo gives you.

Is this overkill? Only you can determine...

[GO DAWG GO]

I just figured I would hear my waistgate blubbering more often with the K27HFS. Obviously I'm wrong. The write up says it will spool up like a regular k27 and deliver charge at higher RPMs.. better than its little brother the K27S.

My rationale: Everybody said the k27s and 7200 will die at ~5600 RPMs Correct? Naturally I correlated high charge energy with higher RPM capability. The 2600 spool up sounded like the best of both worlds.

I have build many Hi-performance VW engines for sand rails with big cams. Sacrifice your low end for high end. Depends on what the owner need are.

Maybe I was confused with the lower RPM spool up at ~2600 RPM thinking this would be a efficient as the K27S at 2600+ RPM's

Is my low end going to blow...no pun intended!

[kellcats521]

Originally Posted by robert_snyder

I just figured I would hear my waistgate blubbering more often with the K27HFS. Obviously I'm wrong. The write up says it will spool up like a regular k27 and deliver charge at higher RPMs.. better than its little brother the K27S.

My rationale: Everybody said the k27s and 7200 will die at ~5600 RPMs Correct? Naturally I correlated high charge energy with higher RPM capability. The 2600 spool up sounded like the best of both worlds.

I have build many Hi-performance VW engines for sand rails with big cams. Sacrifice your low end for high end. Depends on what the owner need are.

Maybe I was confused with the lower RPM spool up at ~2600 RPM thinking this would be a efficient as the K27S at 2600+ RPM's

Is my low end going to blow...no pun intended!

Overkill: putting a huge EFI setup on a tame motor, or putting 2.5" primary headers on a 2.7 motor.
You've done the same thing - the turbine side of this HFS needs BIG AIR to spin the wheels. It is for sure an efficient design that will do better than say a K-29 (similar sized unit with older housing/wheel technology), but the bottom line is that the exhaust flow of a stock motor w/stock exhaust is waaay to low (especially at low RPMs) to make this turbo cook.

What this turbo will do on your motor is this: lag more than the stock unit at low RPM, then produce BIG boost from ~3.5K-4.5K which will quickly hit the wastegate and open it - once the gate is open, you have no more boost than ANY other turbo that opens the gate (including that 3LDZ which also opens the gate all the way to redline). I'll 'maybe' allow that the intake charge will be a few degrees cooler than your OE turbo produces, but that's it.....

This issue that a 3LDZ or K-27/7008/7200 'runs out of steam at 5K' (or whatever RPM) is BS IMO when you look at a stock 930 motor. Every turbo
I've been exposed to will trip a 0.7 bar spring way before 5K, and keep the gate open up to redline. If the gate is open, you're bleeding off boost. Who cares if the turbo is producing less at 6K than it did at 4.5K when the gate opened, it's still making more than you can use. It's only when you get into big motors that can handle 1.0 bar (actually more than 1.0) that you will EVER see one of these turbos 'blow soft enough' to close a wastegate at high RPM, thereby justifying an upgrade.

I agree with the concensus in that you asked questions too late - I have a very bad opinion of the B&B I/C as well as agreeing with others in that you have waay too much turbo. I have a fairly built CIS motor (3.3 with euro head,lines, injectors, C2 cams, modded WUR, and 1.75" headers), and IMO the HFS is too much turbo for me....

Pat K
87 930

[rsrfan]

At the very least, I would recommend headers. They will reduce lag/bring the boost on sooner with the HFS. From my understanding, the K27HFS is a great turbo with a very linear boost threshold which flows well past 7000 RPM. The question you should be asking yourself is how often are you at 7000 RPM. If you are predominantly driving on the street, the K27 7200 or K27S might be a better turbo. For track work or sustained high boost sessions, the K27HFS might be the ticket. I have communicated with several members running the K27S with cams and headers and they all report that boost begins at 1600 - 1800 rpms and the car has an almost naturally aspirated response feeling. When I upgrade my K27 7006 this fall, I am going with the K27S. However, my car is 99% street driven and weighs 2600 lbs +/-.

JP

[RarlyL8]

I think you got your answers.
Don't beat yourself up over it, your goals have just been set a little higher that's all. You can pump up your motor to match the new turbo and then thumb your nose as you blow by us!

[Facey]

a little harsh on the responses....

however i believe the answers to your questions are somewhere in there.

1. yes its alot of turbo, which it doesn't sound like you'll be using. HOWEVER, there will be some advantages but with some very noticeable down sides (LAG)...

headers will help fix that problem, as will some head work. what you'll have is a wastegate working over time (which it should be able to handle...very simple device).

[NathanUK]

Robert, maybe you could ask Stephen if he can give us some info on exactly how many rpm's later the HFS will spool up compared to the S?

A guy on the Rennlist 964t forum replaced his stock K27 on his 3.6 964t with a K27HFS and he says it made his car much easier to control.

Are you considering changing headers soon? If so I would change them now & refit your 3LDZ for a few miles to burn off any crud that may be inside them from when they were welded. This will save wear/FOD to your new turbo. This is what I am doing.