What turbo for high compression??

[jayson427]

I have a built motor 10.5 compression, crower 2 camshafts and im wondering what would be the best turbo to run on that? Im right around 190 hp now and I only want around 300hp. Any suggestions would be great or personal experience with this topic. Thanks

 

[Nicklepage1010]

16g.

 

[Josh97eclipse]

A 50 trim. Piece together a kit

 

[jayson427]

i was looking at a 16g from godspeed but didnt know what was going to work better.

 

[3kgt2nv]

do a hta68. there will be like no lag because of the high compression and you will hit your power goal without much effort and still have room to grow

 

[WES_393]

i was looking at a 16g from godspeed but didnt know what was going to work better.

I would stay far away from Godspeed. They are in the business of cheap knockoffs.


A legit 16g would be a decent choice, but you have to consider how much heat they can produce. High intake temps + 10.5:1 compression = low preignition/detonation threshold. If you want to leave the option of pump gas on the table, you'll want a more efficient turbo.

 

[jayson427]

I would stay far away from Godspeed. They are in the business of cheap knockoffs.


A legit 16g would be a decent choice, but you have to consider how much heat they can produce. High intake temps + 10.5:1 compression = low preignition/detonation threshold. If you want to leave the option of pump gas on the table, you'll want a more efficient turbo.

yeah i want to run on 91 and have no dentonation issues. i know alot of guys are starting to run 10.5 on turbo set ups but i want mine to last. what would you suggest? i know i cant run alot of boost maybe 5-10psi max.

 

[3kgt2nv]

you could do like the honda guys and run a huge turbo on low boost. less psi but more airflow

 

[Slo2gen]

190 ehh, have a Dyno chart? For that kind of power I would recommend a 20g or something around that. If you wanted maybe even a HX35 if your on that band wagon.

 

[jayson427]

No dyno chart but I have smoked a few of the new scion tc's which have a 180hp so I know im a bit above that. I have a lot of motor work done. appreciate the tips but still doesn't give me enough info to just go buy a 20g or something else. Ill just keep looking. I would like to read on someone that has done this with a 420a

 

[dsmcrzy]

OP I have a 10.5:1 engine as well and I got a evo3 16g to run on mine but I also plan on running meth injection to help keep the intake temps down. Might be something to look at. I know guys over at 2gnt.com have higher comp 420As. Adding meth is definitely a safe way to protect your engine and if you have a megasquirt you can easily piece together a kit since the 2 expensive parts are the controller and the pump.

 

[xxNocturnalxx]

Yep, 180 to the flywheel, which would be roughly 145-150 to the wheels depending on the dyno, I'm sure the TC weights a bit more also. Anyways I agree with the 20g sized turbo ideas, focus a little more on airflow than boost.

 

[bryanwheat]

yeah i want to run on 91 and have no dentonation issues. i know alot of guys are starting to run 10.5 on turbo set ups but i want mine to last. what would you suggest? i know i cant run alot of boost maybe 5-10psi max.

10.5:1 compression with a turbo and 91 octane sounds like a recipe for disaster. You could probably get away with 93 if you scale back the timing a lot, (i assume that you will be using megasquirt), but you won't make good power.

 

[Josh97eclipse]

I am running a godspeed turbo for 2k miles now so far no problems, I do not plan on keeping it much longer.....Only till I can save up for a turbo manifold to be made so I can run a holset

 

[ramsack]

I just wouldn't bother. I would either lower your compression ratio goals for the fuel you intend to run or raise your fuel octane to match your compression ratio goals. I wouldn't bother with that high of a compression with even 93 octane.

 

[glowryder]

turbo wont really matter.. any choice will be ok (within reason..

This is the most important thing here "10.5:1 compression with a turbo and 91 octane sounds like a recipe for disaster"

You better have MS standalone to tune the fuel and timing precicely, b.c at that compression, youll need it. Your question should be " hwo safe is it to run boost on high CR?" Its safe as long as youhave the tune.. The reason people gow Low CR is for a larger "tolerance" in the tune. Your tolerance for mistakes/Det on that CR is little to none.. one det could easily take you out. GL.

 

[ramsack]

People use a low compression ratio because they want to run pump gas, make horsepower, and not have dog-shit retarded timing. Those cars are the ones that spool at nearly 6k. You'll find with a ratio that high on pump that it's going to be an endless battle to keep a tune that will be knock-free. I also don't agree that one knock event is going to grenade the thing. Obviously to get to 10.5:1 it's going to have high quality parts and everything will be clearanced for boost. It wouldn't be even close to akin to running a 9:1 n/a 4g63 block with a turbo on it.

 

[glowryder]

"People use a low compression ratio because they want to run pump gas, make horsepower, and not have dog-shit retarded timing." Thats the same differnce as tuning window... It not really "tuned" , just tuned to work. It makes the turbo work more. No, 1 event MAY not kill it, but it very well could.. and has been done.. depends on tuning and the size of the event.. Regardless, he will be way more supseptibule to a catostrphic event with that CR.

I run 9:1 boosted, thats as high as i felt i needed to go for a street car. To me High CR is for N/A builds or drag cars.

 

[LandSpeed-DSM]

An engine that is less thermally efficient (lower static or dynamic compression) has more heat energy in the exhaust gas to spool the turbo.

Higher comp motor will pull through the spool up transition faster, arguably, due to greater off boost torque. But a lower comp motor is not necessarily spooling later.

I've run anywhere between 10.4:1CR and 7.5:1CR on my turbo motors, and for the LSR/Mile motor I am using ~8.0:1CR.

You can get away with 10.5:1, but there is less margin for error as noted. You will make more power on less boost, all other things held equal.

91oct is only going to make the safety window smaller. Look into a serious intercooler and water or water/meth kit if you have no other primary fuel options.

 

[glowryder]

"You can get away with 10.5:1, but there is less margin for error as noted. You will make more power on less boost, all other things held equal." exactly, this is what im trying to get across. Its all a balance.. To add to something , you have to take from something, Its a law (Literally).

"91oct is only going to make the safety window smaller. Look into a serious intercooler and water or water/meth kit if you have no other primary fuel options. " This is good advice, but this also makes your tuning have added complexity, and your also relying on more vairables. Dont get me wrong, alll possible, but your asking "what turbo works" , , and no offence, that tells me you dont have much of an idea of whats going on...Just my .02.

300 is an easy target on a low comp 420a With boost. 6 psi is in the 210 range (depending on tune. so few more pounds and youre there. But do you have the trans upgrades to support 300 would be my question.. GL

 

[LandSpeed-DSM]

I missed the 300whp goal, this should be pretty easy.. and if you are only injecting water with a small nozzle, like 1gph pre or post compressor you won't have to touch your tune unless you want to get more agressive with it.

If you are adding meth to it, you will have to play with your tune. Meth has a different AFR scale vs. lambda.

 

[L1v1ng L3g3nd]

Because of an ACL bearing failing in my built block, I am driving an 4G63 non turbo block right now on my car (10,4 compression).

With 0,8 Bar boost on the HTA68 and 95 octane I see no knock - never.

I produce that boost at under 3.2k rpm

 

[Slo2gen]

People have been running higher compression boost for a long time now. You are right, the window for error is a LOT smaller, but for only 300 whp it would be an awesome street car. Look at Honda's. How many stock motors get boosted and make good numbers with low boost, and they are running on 93/91 octane. Its very doable. I still say S20g, IMO its one of the best all around street turbo's. For what its worth I'll add my numbers in here....my 2gnt-t was a 10.5:1 motor with an S25g, made 415whp/365wtq @17psi. My Honda was a 10.2:1 stock motor with a T3 Garrett 60-1 and made 420whp/265wtq @ 10psi.

 

[Josh97eclipse]

I can vogue for both zacs cars....He no longer messes with low comp....its boring and a dog out of boost, I already want to build a high comp motor for my 2gnt.

 

[jayson427]

People have been running higher compression boost for a long time now. You are right, the window for error is a LOT smaller, but for only 300 whp it would be an awesome street car. Look at Honda's. How many stock motors get boosted and make good numbers with low boost, and they are running on 93/91 octane. Its very doable. I still say S20g, IMO its one of the best all around street turbo's. For what its worth I'll add my numbers in here....my 2gnt-t was a 10.5:1 motor with an S25g, made 415whp/365wtq @17psi. My Honda was a 10.2:1 stock motor with a T3 Garrett 60-1 and made 420whp/265wtq @ 10psi.

well how is your 2g holding up? have you had any big break downs with your set up? and what kind of fuel do you run?

i only have 91 and 95 in my town so i could run 95. im fine with my car now its fast for a 420a n/a. i just know down the road i want to turbo it and im making good money right now to save up soon to do so. im just trying to get a head of the game and find out what i need to do. i know your suppost to run lower cr but i have seen a few 420's run higher cr with a turbo but i never knew their out come or longevity of the motor. i have heard of all the stories of not doing it right and blowing motors. thats why im making this thread like i said all i want is around 300hp nothing crazy. its my weekend driver when im not working over the road.