I have done some reading. I know that if im going to get a K27 that I will get a K27/8. I know that it is only a tiny bit laggier than the K27/6. But thats all I know about these. I know the basics on turbo charging and thats about it. The topic is very confusing to me.

My situation is that I have a K28. I know that technically the K28 is a hybrid that being a K27 hot side with a K29 cold side. I love this turbo because it hits hard as hell. But its laggy. I do a lot of highway driving so for me,... most of the time, its all good. Thats because im always within the rpm range for boost. But if I was to get onto some twisty backroads,.... ehhhhhh. Very ehhh.

I went out with some otehr guys and had some trouble keeping up because of the lag. but on the straights I could of blown them away if there was a second lane

My question is,... how woudl a K27/8 compare to my K28? My goal is 300 - 320rwhp. 300 is easy. But I really want 320. Rigth now I have #65 delco injectors. I plan on getting a dualport wg from lindsey along with their maf. I haver a guru chip but dont nkow if that would be good if I was to run a K27/8. I want to get lindsey's manual boost controller too.

With all that and a K27/8,... would I be able to hit 320? At what rpm does the K27/8 boost? Would it hit as hard as the K28? With the K28 I drive aruodn at 16psi all the time. The PO said he could easily do 18psi which was an ungodly amount of power. Which is great but LAAAAAGY.

What the max psi a K27/8 can produce and can it hold it to redline? When does it run out of breath if at all all. Im just looknig for something hard hitting but sooner to hit. you know?

I know there are always compromises. I just need to know where the K27/8 falls when compared to the K28.

Thanks.

 

Well without knowing a bit more about the turbo you have, it is hard to get a decent understanding. There is no K27 turbine side that will bolt-up to a 951, and a K29 is a big (and ancient) compressor...

So I suppose the first step is to identify what turbo you are actually running.

As for the K27/8 questions - The K27/8 will easily hit 320rwhp. In fact, if that is all you are looking for, then I would go with a quicker spooling K27/6. Either variant will spool slightly slower then their respective K26 turbos, so the K27/6 will be a little bit laggier then the factory Turbo, and the K27/8 will be a bit laggier then the factory Turbo S.

 

Well,.. I know I have a K28. Thats all I know. If I remember correctly I got boost around 3400rpm. And it hit real hard. Well,... I read that the K27/8 kind of tapers off up near redline. Thats means I lose HP right? So top speed wise,... that would suck. So the K27/6 would probably be worse. I kind of like having boost well up to redline and beyond if I could actually drive past redline. I was just hoping for a bit less lag. I kind of want my car for street and track. I want to be able to take it to a track and be able to hit top speeds in my car easily.

Maybe I should just keep my K28 then? I mean,... if im on a road thats not permitting me to boost,... then maybe I shouldnt be boosting Its almost like a safety measure

 

With the Guru chip and that bigger turbo and your injectors, you can run 18psi no problem.

You mention getting a Lindsey wastegate. So you are running a stock/orignal wastegate now? if so then that will greatly add to your lag issues. You could get a new wastegate and notice a major difference in spool and boost "hitting hard" and might not even want a different turbo after that.

Also, you mention a new boost controller. What are you using to control boost now?

So I would suggest a new wastegate first and foremost.

 

i think k27/8 ...............k27/8 with 3" exhaust maf and decent tune will be more responsive then a k26/6 with a full stock car ...
I will never understand why people use a #6 housing that Porsche deemed to small for a 250hp car on a 350hp car
its a question as old as this forum i'd love to see a dyno plot overlay of the 2 turbos

 

Yeah I'm running the stock wastegate. Also everything up to the cat is stock to I believe. My car has a ball and spring reliaboost controller. You think a good wastegate will improve my spool up time that much? I think I am running a stock fuel pressure regulator too.

Todd what wheels you got on your car? Those are nice as hell.

 

A decent wastegate and removing the cat will definitely improve spool-up and response.

 

YES! A new wastegate and cat delete will make it a different car. I got about 500-700 rpm spool up gain for both the new wastegate and cat delete and I have a bigger/laggy turbo than you.

If you are running a Guru chip you should already have a 3bar FPR, but you need to check for sure and get one asap.

The reliaboost is fine.

The wheels are made by BSA and are a GT2 replica 18x8 and 18x10.

 

Really? Then I think I will keep my K28 and just have it rebuilt then. I still want to get the lindsey black know so I can adjust from the inside of the car. I will have to check whether or not I have a 3bar fuel reg. The PO never mentioned it so,... maybe I dont

You gained 500 - 700rpm just by adding a good wastegate and removing the cat!!! Damn! I would looove that. Does you car pas emission without hte cat? I remember reading somewhere that it is possible if you get the turbo hot enough before inspection. I dont know how true that is. And wont they fail you if they dont see a cat under the car? Maybe I'll gut my cat and weld it over the through pipe

And 18" rims too? Nice. I want to run 18's but im afraid. The tech bulletin says dont but so many people are without problems. Its that and im afraid of rubbing. My front 17" rub now with hard turns. Maybe a wide body and stiffer springs/ swaybars would fix that? Your rims are nice. Any side pics of your car?

Oh and your WG,... a Tial 38mm? Between the Tial and the LR,... whcih yuo think is better? Even thoguh you alredy have the Tial The LR is more expensive and they want the core. I dont know if Tial wants the core. Not that I mind sending in the core,... its just that dropping 700+ just for a WG is a bit crazy:\

 

As an FYI, the K26 #8 turbine is approximately 500 rpm later in torque peak than a K26 #6 turbine when driving either a K26 compressor or the K27 compressor.

The K26 #6 turbine will accelerate faster than the K26 #8 as well.

So to answer your question... the difference will be about 500 rpms of when the turbo hits, and the smaller turbine will hit harder as well (apples-to-apples).

The difference is quite a bit on a daily driver street car (more than the numbers would suggest).

TonyG

 

If you are running the stock WG and the original CAT, then yes, I think you will see a pretty significant difference by ditching the cat and replacing the WG.
If you want to run 18" wheels, change to the 968 caster blocks. It's no problem at all, otherwise...just get the correct offset and an alignment to make them work right.
Get the Tial. There's nothing wrong with the LR, but as you mention, the core issue is a huge hassle, unless you like having a few hundred bucks tied up for no good reason.

 

Ok. Will look into the 968 caster blocks for the 18" rims. Or maybe I'll just get some nice wide 17's. Goign to worry abuot the engine first. Once thats done I worry about getting all that power to the road.

I was thinking maybe I'll ask LR if I cuold send in my WG first and then credit towards the purchase so I dont have to dish out and wait for the $300 refund. I dont see why they wouldnt go for that. Or I can just get the tial which is well,... less money.

What about shims for the Tial? LR has shims for their WG. First,.. what are the shims for?

 

I think in 2 weeks im going to go ahead and purchase an engine hoist and stand. I should get atleast a 2ton hoist right? Atleast 1ton for an engien stand? Will any engine stand mount up with my engine? Thanks.

 

You don't need shims for the Tial.

 

Awesome.