Re: What's the most boost used
Posted: Thu Oct 22, 2020 11:43 pm
Good question. It's 1.2mm deck height and as delivered CB Wedgeports (67cc chambers).
It should be 8,1-8,3 or something.
It should be 8,1-8,3 or something.
Shoptalkforums.com
For Your Air Cooled Pleasure!
https://shoptalkforums.com/
What's the most boost used
Page 2 of 4
It should be 8,1-8,3 or something.
Re: What's the most boost used
Posted: Thu Oct 22, 2020 11:45 pm
Splitting a cylinder on a wrongly tuned engine, or other malfunctions are not the same as splitting it by it maxing out it's capabilities.Schweg wrote: ↑Thu Oct 22, 2020 7:49 pmI think those split at around 36 psi. But I can’t seem to find the whole article on how it was set up. Blow through or draw through and ignition timing.madmike wrote:Dave Kadwell did some dyno testing on 94mm pistons & cyl's I'll try and find them results
I remember reading one some where where a guy saw a 45psi spike due to a severed waste gate line then torched a cylinder head. But who knows as his gauge maxed at 45.
Sent from my iPhone using Tapatalk
It will take 45psi on a good tune.
Re: What's the most boost used
Posted: Fri Oct 23, 2020 12:28 am
It also has a lot to do with: what fuel is used.
Bug66 runs E85. Big difference with regard to detonation sensitivity and you can much easier run bigger boost, we sometimes forget.
Most I saw was once on the dyno for 'all out' on my old 2,2 type 4 with the short Oettinger/Mahle alu-nikasil barrels: 30psi at 5-5,2K, then dropping back to 24psi or so (turbo was out of airflow) at max power. That was 465 hp (crank, or about 400 rear wheel) at 6300 or so iirc.
I only run on gasoline (E5) btw
Bug66 runs E85. Big difference with regard to detonation sensitivity and you can much easier run bigger boost, we sometimes forget.
Most I saw was once on the dyno for 'all out' on my old 2,2 type 4 with the short Oettinger/Mahle alu-nikasil barrels: 30psi at 5-5,2K, then dropping back to 24psi or so (turbo was out of airflow) at max power. That was 465 hp (crank, or about 400 rear wheel) at 6300 or so iirc.
I only run on gasoline (E5) btw
Re: What's the most boost used
Posted: Fri Oct 23, 2020 12:32 am
I soooo agree. 99% of all 'split cylinders' do so because of detonation imho, not because of lack of structural integrity.
Re: What's the most boost used
Posted: Fri Oct 23, 2020 2:03 am
I've split my share of cylinders..
It's been because of bad vacuum signal (used 1 runner for the fuel regulator..)
It's been because of bad valve springs
It's been because of splitting a silicone coupler
Never because it just could not hold together
It's been because of bad vacuum signal (used 1 runner for the fuel regulator..)
It's been because of bad valve springs
It's been because of splitting a silicone coupler
Never because it just could not hold together
Re: What's the most boost used
Posted: Fri Oct 23, 2020 11:25 am
Didn't you also run a healthy dose of water/methanol while running that high of boost?Wally wrote: ↑Fri Oct 23, 2020 12:28 am It also has a lot to do with: what fuel is used.
Bug66 runs E85. Big difference with regard to detonation sensitivity and you can much easier run bigger boost, we sometimes forget.
Most I saw was once on the dyno for 'all out' on my old 2,2 type 4 with the short Oettinger/Mahle alu-nikasil barrels: 30psi at 5-5,2K, then dropping back to 24psi or so (turbo was out of airflow) at max power. That was 465 hp (crank, or about 400 rear wheel) at 6300 or so iirc.
I only run on gasoline (E5) btw
Re: What's the most boost used
Posted: Fri Oct 23, 2020 11:33 am
Indeed! always have used 50-50 water-meth injection, plus big intercooler, plus knock sensing and control (but its still no match for E85).Chip Birks wrote: ↑Fri Oct 23, 2020 11:25 amDidn't you also run a healthy dose of water/methanol while running that high of boost?Wally wrote: ↑Fri Oct 23, 2020 12:28 am It also has a lot to do with: what fuel is used.
Bug66 runs E85. Big difference with regard to detonation sensitivity and you can much easier run bigger boost, we sometimes forget.
Most I saw was once on the dyno for 'all out' on my old 2,2 type 4 with the short Oettinger/Mahle alu-nikasil barrels: 30psi at 5-5,2K, then dropping back to 24psi or so (turbo was out of airflow) at max power. That was 465 hp (crank, or about 400 rear wheel) at 6300 or so iirc.
I only run on gasoline (E5) btw
All because detonation is a bitch!
Re: What's the most boost used
Posted: Fri Oct 23, 2020 12:19 pm
Very interesting. I would have thought it would have started to lift the heads at 40 psi or so.
I'm running stock rods so i won't be trying anything nuts myself, but i was really just more curious than anything. Most likely be limiting myself to 25 psi or so with this turbo. I run E85 most of the time too. Small turbo on a 2054 with 1 3/8" header.
I'm running stock rods so i won't be trying anything nuts myself, but i was really just more curious than anything. Most likely be limiting myself to 25 psi or so with this turbo. I run E85 most of the time too. Small turbo on a 2054 with 1 3/8" header.
Re: What's the most boost used
Posted: Fri Oct 23, 2020 12:47 pm
My opinion (FWIW) on 'small turbos' is maybe even more interesting: they kill motors more then big turbo's.
Another one: your 25 psi is 'completely' different then my 25psi with my turbo...
How about that?
Re: What's the most boost used
Posted: Fri Oct 23, 2020 1:04 pm
For sure it's different! That may be a whole new topic coming up!
Re: What's the most boost used
Posted: Fri Oct 23, 2020 2:06 pm
Is it more a sustained boost issue with the small turbos?
Re: What's the most boost used
Posted: Sat Oct 24, 2020 12:34 am
My guess would be a big turbo 25psi is cooler than a small maxed out turbo at 25psi
Verstuurd vanaf mijn SM-A515F met Tapatalk
Verstuurd vanaf mijn SM-A515F met Tapatalk
Re: What's the most boost used
Posted: Sat Oct 24, 2020 6:28 am
Yea if i remember correctly it was 36 lbs, on a draw threw 1915cc , I thinking it was tuned correctly too , Dave knows his $hit 
Re: What's the most boost used
Posted: Sat Oct 24, 2020 7:00 am
Dave definitely knows his $hit. I could have sworn it was much lower boost than that. Seems like i had that link saved but was no longer there.
Edit: found this post about it.
viewtopic.php?f=3&t=102753
Edit: found this post about it.
viewtopic.php?f=3&t=102753
Re: What's the most boost used
Posted: Sat Oct 24, 2020 7:06 am
The forum discussing said 36 for sure. Detonation and a bent wrist pin. They also where running just some aa 94s and showing how you can push not so high performance parts.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk